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smallyachtsailor
04-04-2016, 12:23 PM
Hello all. I'm not new on the forum but haven't posted very much--mostly been mooching ideas from everyone else for years. A couple weeks ago I started building a new boat of my own design, hoping to finish it in time for the Wooden Boat Show. I thought some of you might be interested in this rather different type of boat. I've been designing and building kayaks and other small boats for about 45 years now--mainly just as a hobby. This new boat will be a 17-foot car-toppable boat for two persons (my wife and I) propelled by two Hobie Mirage drives. Last year I finished a single Mirage drive boat and showed it at the Wooden Boat Show, so this is a development of that one.

Here's a couple photos of last year's boat:
http://www.wildlifeofct.com/wbfphotos/wood duck 06sm.jpg
http://wildlifeofct.com/wbfphotos/0992sm.jpg

And here's a video of it moving along at near full speed:

https://www.youtube.com/watch?v=6FSkU-7hGLY&feature=youtu.be

The boat is so comfortable and fast that I almost feel guilty using it after a few decades of roughing it in sea kayaks. My wife likes it too, and so a double is needed.

and here's an early sketch of this year's double:

http://www.wildlifeofct.com/wbfphotos/1737sm.jpg

Construction will be my usual; batten-seam using 1/8" okoume plywood over frames. I've optimized the design to match the Mirage drive's characteristics. It should have a top speed of perhaps 7 mph (I can hit 6.5 mph with last year's 16-foot model), but that takes a fair effort and I'm not 20 anymore. More pointedly, the Mirage drive is great at cruising at about 4 or 5 mph, so I've designed this hull to easily reach that speed with minimal effort. I've attempted to minimize wetted surface in a fairly stable boat of about 30" beam at the sheer, and to build in a goodly amount of seaworthiness.

I've got a week or two of building to post, which I'll do shortly. I hope you enjoy the thread.

smallyachtsailor
04-04-2016, 01:10 PM
After the initial sketch I draw up the plans to a larger scale, then loft full-size patterns for the frames and upper side panels (uppermost strakes). Then, using battens, I lay out the side panels on 1/8" okoume plywood:

http://www.wildlifeofct.com/wbfphotos/1739sm.jpg

Next, the side panels are cut out--a utility knife works well here, or a sabre saw:
http://www.wildlifeofct.com/wbfphotos/1741sm.jpg

The boat has four strakes per side, and 9 battens, 3/4" square, which run the full length of the boat. I use a disk sander and jig to scarf them to the full 17' lengths:
http://www.wildlifeofct.com/wbfphotos/1742sm.jpg

I find it handy to use some lengths of aluminum angle to clamp the battens in position while gluing the scarfs. Properly clamped, this ensures the joints are straight:
http://www.wildlifeofct.com/wbfphotos/1744sm.jpg

smallyachtsailor
04-04-2016, 01:23 PM
The uppermost, or sheer strakes are assembled first with battens on each edge, one batten becoming a sheer clamp:
http://www.wildlifeofct.com/wbfphotos/1750sm.jpg

On this particular boat I'm joining the panels with butt blocks, also of 1/8 okoume ply, rather than scarfing the plywood because I like the extra strength and stiffness added by the butt blocks. Mainly because as you'll see further on, the center frame is centered on these butt blocks.
http://www.wildlifeofct.com/wbfphotos/1752sm.jpg

The center frame divides the 10-foot double cockpit evenly in half. As you can see below, it's made of 1/8" plywood and incorporates a thwart. The interior curve is stiffened by laminating strips of pine--and mahogany uppermost for appearance. This makes for a very lightweight and stiff frame:
http://www.wildlifeofct.com/wbfphotos/1763sm.jpg

The small transom is reinforced on the inside and already has the knees attached--making it easier to set up the whole boat frame and align the side panels:
http://www.wildlifeofct.com/wbfphotos/1764sm.jpg

Rich Jones
04-04-2016, 01:30 PM
I'll be interested to see the project. Learning to post pics on this forum is a pain!

ZZ
04-04-2016, 01:37 PM
SYS, your pix aren't showing up, try Thorne's thread;

http://forum.woodenboat.com/showthread.php?121390-Thorne-s-new-and-improved-quot-how-to-post-photos-quot-instructions/page2.

I liked your boat at last year's show, took a couple of pix. Looking forward to seeing you and your new design this year, build fast!

ZZ

smallyachtsailor
04-04-2016, 01:43 PM
The stem being tested for fit at the forward end of one of the side panels:
http://www.wildlifeofct.com/wbfphotos/1768sm.jpg

Although the hull is hard-chined, I decided I wanted a smoothly-curved transom for appearance's sake. So in the photo below, the odd clamping arrangement is being used to curve the aftmost ends of the side panels to match the corresponding curve on the transom. Pre-setting this curve in the side panels makes assembly much easier--it's one less thing to worry about while you're trying to align all the frames and side panels:
http://www.wildlifeofct.com/wbfphotos/1772sm.jpg

All the parts needed to start assembling the frame are finished. The two solid bulkheads go at each end of the cockpit, forming watertight compartments at each end of the boat:
http://www.wildlifeofct.com/wbfphotos/1773sm.jpg

And now what I call the "wobbly stage". Using strap clamps, tape, whatever works. First you tape or strap the side panels together at bow and stern, then bow them apart and insert the frames and transom:
http://www.wildlifeofct.com/wbfphotos/1774sm.jpg

Here's a view of the bulkhead at the aft end of the cockpit, already notched for the rest of the battens, and the transom temporarily in place. Nothing is glued until everything is checked for fit and alignment. The whole frame is resting on two parallel and level crossbeams--those do most of the work of ensuring the boat is straight.
http://www.wildlifeofct.com/wbfphotos/1778sm.jpg

smallyachtsailor
04-04-2016, 01:50 PM
Thanks for the replies. I did check with Thorne's instructions and the pics seem to be working now. Thank you Thorne! Simple and yet somehow tricky if you don't know the right procedure.

I should be at the WBS even if this boat isn't finished in time, but I think I can do it. My wife does most of the finishing work, so that saves me a lot of time--besides, she's better at it than me. Finished boat or not, my brother plans to be there with his new guideboat, and the Mystic Seaport Ship Modelers will be showing off some of their boats also (I started the group a few years ago).

rgthom
04-04-2016, 02:10 PM
Hmm, still not seeing the pics. Looks like they are in a Dropbox folder which is not public. I would like to see your boat!

Thorne - Does Dropbox work for picture sharing?

smallyachtsailor
04-04-2016, 03:17 PM
At this stage the keelson is inserted temporarily to make sure the hull is straight and the curve of the rocker is as intended. So far everything looks very good--exactly as planned. There will be two more intermediate frames in the cockpit, although I've already decided that two additional frames planned at the bow and stern won't be needed. It'll be plenty strong enough without them, so I might as well save the weight.
http://www.wildlifeofct.com/wbfphotos/1784sm.jpg

Here's the stem inserted with the keelson laying on top of it. Once I'm sure of all alignments I'll go around and glue the joints one at a time:
http://www.wildlifeofct.com/wbfphotos/1786sm.jpg

The keelson lying in the frame notches:
http://www.wildlifeofct.com/wbfphotos/1788sm.jpg

Ok now I'm caught up to date. I'll keep posting more pics as I make progress. Off to volunteer at the Seaport tomorrow so I may not get much done till Wednesday.

Rich Jones
04-04-2016, 03:33 PM
Very nice. Will be following with interest.

rgthom
04-04-2016, 05:05 PM
Great. I like last year's, looking forward to the new one.

smallyachtsailor
04-06-2016, 02:38 PM
Today I'm getting several of the frames glued in to the side panels. This is the center frame that divides the double cockpit in half. Lots of clamps to hold everything in proper position, and I reinforce the side panel/frame joints with triangular "fillet" strips. I don't like to use epoxy fillets or fiberglass because it adds so much weight.
http://wildlifeofct.com/wbfphotos/1793sm.jpg

smallyachtsailor
04-09-2016, 07:30 PM
Here's the transom being glued in place with clamps going all which way. At the same time I put the keelson strip in place and check the entire hull for alignment. Getting the transom square across the hull is key.
http://www.wildlifeofct.com/wbfphotos/1795sm.jpg

And at the other end, the same process with the stem. Note that in order to keep the "C" clamps from sliding off the bow, I first clamp sticks on each side of the bow that are notched at the end to offset the "V" of the bow. The "C" clamps are then clamped over these sticks and don't slide off!
http://www.wildlifeofct.com/wbfphotos/1796sm.jpg

With the bow and stern glued, the boat's frame really starts to firm up and there's less worry about getting something out of alignment.

Two more frames to make for the cockpit area. These are open frames that are positioned near the front edge of the two seats that will eventually be installed. Here, the laminated reinforcing strips are being glued in place around the inside edge of one of the plywood frames. Lead weights hold the frame flat on a worktable:
http://www.wildlifeofct.com/wbfphotos/1798sm.jpg

Eleven weeks to the WBS!

ZZ
04-11-2016, 02:19 PM
Excerpt from another thread;

Mirage Well Assy.

It's suggested for boat building projects, they finally recognized us.

http://www.hobiecat.com/forums/viewt...0cd1b378fcf935 (http://www.hobiecat.com/forums/viewtopic.php?f=60&t=50883&sid=e6a2dc0535a133e1de0cd1b378fcf935)

Your well needs to be the depth of the boat's draft plus a 3" or so.




79050001 MIRAGE WELL ASSY - INFLATABLES

5 1/2" Tall

smallyachtsailor
04-12-2016, 03:09 PM
Excerpt from another thread;

Mirage Well Assy.

It's suggested for boat building projects, they finally recognized us.

http://www.hobiecat.com/forums/viewt...0cd1b378fcf935 (http://www.hobiecat.com/forums/viewtopic.php?f=60&t=50883&sid=e6a2dc0535a133e1de0cd1b378fcf935)

Your well needs to be the depth of the boat's draft plus a 3" or so.





79050001 MIRAGE WELL ASSY - INFLATABLES

5 1/2" Tall











Thanks ZZ. I've noticed that even compared to a few years ago, Hobie drives and accessories like the drive mount you mention are far more widely available, which is good, and a reflection of the fact that more people are building them into boats themselves. Last year at the WBS in Mystic, a fellow from Australia came by several times and meticulously measured and photographed the drive mount in my first Mirage drive boat. He was going to put one in a kit boat--I think it was one of the CLC boats--the Mill Creek if I recall corrrectly. As with my first mirage drive boat I'll again build my own drive mounts out of wood. I use two large screws with knobs to hold the drive in, and I'll probably do so again. Someone (also last year at the WBS) said he liked my system better than Hobie's because Hobies mounting system with the two levers sometimes popped loose on him. I don't know about this myself since my wife and I only tried the drive unit for an hour or so once in a Hobie-built boat. But that was all it took to convince me to get a drive unit and build my own boat.

ZZ
04-12-2016, 04:21 PM
There's an excellent photo of your mounting setup on the WBS slideshow for the "I Built It Myself" category. http://www.thewoodenboatshow.com/ibim.php Scroll down to the slideshow. I think your boat is in about ten photos.

Woxbox
04-12-2016, 07:27 PM
Nice. I like your approach, working with wood on wood instead of mixing in the glass and chemical goop from the get-go. What glue are you using where it's needed?

Reynard38
04-12-2016, 09:24 PM
Man that thing really moves.

smallyachtsailor
04-12-2016, 09:39 PM
Nice. I like your approach, working with wood on wood instead of mixing in the glass and chemical goop from the get-go. What glue are you using where it's needed?

Thanks. I go for light weight and stiffness, and of course glass is neither of these, so I mostly avoid it. I think the only thing I've used fiberglass on in the last 20 years were paddle tips for abrasion resistance, and for that it's worked fairly well. I've always built my kayaks and other boats using seam batten construction instead of glass tape or other. I find on a typical plywood kayak, it saves 10-15 lbs. My 18-foot sea kayak weighs in at about 39 lbs--easy on the back, and behaves much better in the water.

In this current build I use whatever glue best suits the purpose--from epoxy to woodworker's glue (the yellow stuff), polyurethane, even CA at certain times for tacking. It really depends on the tightness of the joint and how much working time I want. I tend to prefer using the less noxious stuff whenever possible, and anything that is at least water-resistant. These types of lightweight boats are only in the water for a few hours at a time, so as long as you keep up the finish water should never even get to the glue. If it does, you've got a lot more problems than some glue joint failing. That's one thing I've learned over the years--maintenance of the finish is more important than what you initially choose to finish the boat with. My oldest boat is a skin-on-frame kayak about 35 years old now--covered in canvas duck and painted with latex housepaint. Aside from one small tear in the canvas, the paint is still good.

If I get a scratch through the finish on one of my plywood boats I let the boat dry out thoroughly and then seal the scratch before I use the boat again. Then a light sanding and fresh coat of varnish or paint every other year or so. Of course without a thick layer of glass on the bottom of the boat, you don't want to be dragging them up onto gravel, but then I wouldn't if I owned a $3000 kevlar boat either.

smallyachtsailor
04-12-2016, 09:50 PM
Man that thing really moves.

Yes, I was very impressed when I first tried a Mirage drive. The Hobie sit-on-top kayak it was mounted in was far too short and couldn't get out of its own way, but the power in the drive unit was amazing. I've kayaked for a few decades now and--at least when I was younger--could maintain 7 mph in my 18-foot sea kayak for a mile or more. Now, speed is nice, but nowadays I'm more interested in going a reasonable speed with less effort, and the Hobie drive fits that bill. I think even in a longer, sleeker boat a Mirage drive would still probably limit-out at perhaps 7 or so mph. I don't think you could work the pedals much faster--beyond a certain point I think you'd just be flailing the water. However, last summer I had no trouble keeping up with (or perhaps leaving behind!) my sea kayaking friends, especially after a few hours of paddling. Arms tire more rapidly than legs.

smallyachtsailor
04-19-2016, 06:28 PM
All the frames and bulkheads are in and here's the keelson gluing in:

http://wildlifeofct.com/wbfphotos/1805sm.jpg

While I still have access for simple clamps, I decided to glue the lower rubbing strake (cherry) in place. There'll also be an upper rubbing strake at the sheer.
http://wildlifeofct.com/wbfphotos/1806sm.jpg

Now that it looks like I might actually finish this thing by the WBS at the end of June, I decided on a name (Pinniped--literally "finned feet") and registered for the I Built It Myself part of the WBS.

Now to put the rest of the stringers in place. Here's a join at the transom end of things. I can't recall the name of this type of angled joint--anyone know it? I thought there was a particular name for it.
http://wildlifeofct.com/wbfphotos/1815sm.jpg

Here's all the stringers finished at the bow. Those 3/4" square stringers took some soaking at the ends before they'd twist enough:
http://wildlifeofct.com/wbfphotos/1819sm.jpg

smallyachtsailor
04-19-2016, 06:36 PM
Bow view with the frame completed. The keelson is nice and straight, which is usually a good thing!
http://wildlifeofct.com/wbfphotos/1821sm.jpg

And a view from the stern. This perspective makes the rather small transom look much bigger than it really is.
http://wildlifeofct.com/wbfphotos/1822sm.jpg


And a view from the side, sort of. I haven't much space to build, so my wife allows me to commandeer a big patch of basement and get sawdust all over, including in our cat's hair. Boats everywhere, and I still don't really know where this one will live when it's not in the water.
http://wildlifeofct.com/wbfphotos/1824sm.jpg


An inside view down the cockpit frames makes a pretty picture:
http://wildlifeofct.com/wbfphotos/1828sm.jpg

Time to clear the building table and start planking the bottom of the hull. I'm hoping to finish that by the end of the month if not earlier. Still on track I think. In the meantime I've gotten some other parts done to be added later--rudder, handles, etc.

lupussonic
04-19-2016, 07:15 PM
Following with interest, loving your work.

ZZ
04-20-2016, 10:52 AM
"Here's a join at the transom end of things. I can't recall the name of this type of angled joint--anyone know it? I thought there was a particular name for it."

Blind mortice? Blind lap? Who cares? The build is coming along fine and you've still got time. Hope nothing gets in the way before the WBS.

ZZ


http://wildlifeofct.com/wbfphotos/1815sm.jpg

smallyachtsailor
04-24-2016, 10:13 AM
Here's most of my collection of larger pony clamps working hard. I figure if you have them, use them. I'm doing the hardest planks first, at the forefoot. They're twisted about 80 degrees over 4 feet, but pretty narrow so they really were no problem.

http://www.wildlifeofct.com/wbfphotos/1832sm.jpg

Another plank clamped and gluing. I'm doing the garboard strakes first. I have a few boxes full of they plywood "clamps" and a box full of wooden wedges from previous builds.

http://www.wildlifeofct.com/wbfphotos/1837sm.jpg

Before the planks can be put in place of course the outer surfaces of the battens need to be cambered. I mostly use a wood rasp with one end taped over. With lines drawn down the centers of the battens, its easy to get the correct angles by resting the taped end of the rasp on the next batten. Remove wood up until the pencil line begins to be removed, then turn the rasp around and do the other batten.

http://www.wildlifeofct.com/wbfphotos/1840sm.jpg

I count four different types of clamps now; pony, "C" clamps, bar clamps, and those plywood and wedge things:

http://www.wildlifeofct.com/wbfphotos/1841sm.jpg

One thing I really like about this plywood and wedge clamping system (besides the price) is that it is very quick to put in place. Sliding wedges in is far faster than turning "C" clamp screws. And of course they can be made in any dimensions and can reach across and clamp both sides of a plank at once.

http://www.wildlifeofct.com/wbfphotos/1842sm.jpg

Still on schedule and already more than half the hull is planked. At least three planks will go on today, and maybe more.

NoEyeDeer
04-24-2016, 04:02 PM
Good thinking on the taped rasp. I hadn't thought of doing it that way. I've always relied on the old rebate-plane-with-screw-in-guide, but I can see the rasp being an advantage at times.

I agree about the plywood and wedge clamps too. I find them very quick and convenient. I also use wedges for clamping laminations around a jig. Much easier and faster when I'm trying to get a bunch of steamed or sticky strips to behave.

smallyachtsailor
04-25-2016, 01:42 PM
Good thinking on the taped rasp. I hadn't thought of doing it that way. I've always relied on the old rebate-plane-with-screw-in-guide, but I can see the rasp being an advantage at times.

I agree about the plywood and wedge clamps too. I find them very quick and convenient. I also use wedges for clamping laminations around a jig. Much easier and faster when I'm trying to get a bunch of steamed or sticky strips to behave.

Yes, the rasp works in some situations, but I also use a plane at times; whichever is easier or does the better job. The plywood/wedge clamping has another advantage in that you don't have to worry about leaving marks in the wood or having to use clamping blocks to avoid "C" clamp circles.

Only 8 more planks/panels to go, that's out of 24 total on the hull, so 2/3 of the way!

smallyachtsailor
04-29-2016, 06:29 PM
Lots of spiling this week. Counting down to the last planks:

http://www.wildlifeofct.com/wbfphotos/1855sm.jpg

And finished with the hull planking before my end-of-the-month goal:

http://www.wildlifeofct.com/wbfphotos/1856sm.jpg

Here's a view from straight on the bow. The keel strip (cherry) still needs to be faired in along the stem.

http://www.wildlifeofct.com/wbfphotos/1858sm.jpg

And a stern-view. I just noticed looking at this that I have one more plank end to trim at the transom, on the starboard side...

http://www.wildlifeofct.com/wbfphotos/1859sm.jpg

After some sanding of seams I'll get the boat turned over--maybe tomorrow even. Then there's lots to do in May: seal the inside, decks, cockpit coaming, hatches, Mirage drive boxes, seats, and steering gear and rudder. I'm also planning a two-wheel dolly and some rollers up on the back of my car. This boat will be heavier than my previous, but I still want to car-top it.

Marco Giai-Coletti
04-30-2016, 12:16 AM
How do you seal the seams, i.e. where the plywood panels meet each other?

smallyachtsailor
04-30-2016, 09:10 AM
How do you seal the seams, i.e. where the plywood panels meet each other?

Good question. In seam-batten construction the 3/4" x 3/4" longitudinal battens are behind and overlap the panel seams. The panels are glued to the battens and edge-to-edge to each other. What I'm doing now (and my wife is helping) is filling any gaps in these seams with glue and immediately sanding the outside. This thickens the glue with sanding dust and fills the seam, and at the same time smooths the outside of the panel join. It's a quick and easy way to do all of it at once. Since I'm painting the hull below the rubbing strake you see on the hull already, I don't have to be too careful, it just needs to be smooth. So the short answer is that the seams are thoroughly glued. Compared to stitch-and-glue, I find seam-batten construction saves me something like 10 to 15 lbs of weight in a boat like this, or a kayak, since no fiberglass is used (it's the weight of all the epoxy needed to fill that fiberglass that is so heavy). This seam-batten construction on frames also lets me attain exactly the hull shape I desire.

tom151
04-30-2016, 12:26 PM
Great stuff... thanks for the very nicely detailed pictorial of the build. Love it - giving inspiration to try this batten-seam approach for a boat I was planning as S&G.

Really appreciate you comparison to stitch-and-glue, weight-wise.

If using epoxy, are you using any structural filler at all in the joint where the ply is glued to the batten?

Cheers,

smallyachtsailor
04-30-2016, 01:26 PM
Great stuff... thanks for the very nicely detailed pictorial of the build. Love it - giving inspiration to try this batten-seam approach for a boat I was planning as S&G.

Really appreciate you comparison to stitch-and-glue, weight-wise.

If using epoxy, are you using any structural filler at all in the joint where the ply is glued to the batten?

Cheers,

Glad you're enjoying the thread.

I've been building with batten-seam (or seam-batten--whatever!) construction for a few decades, and frankly I don't remember why I chose it. I have not found a better alternative unless you go to lapstrake ply. To give you an idea of weight saving, my 18-foot sea kayak (batten-seam) weighs 39 lbs. The lightest similar production 18-foot kayak I could find was a $3000 kevlar boat that weighs 45 lbs. Of course in fiberglass you'd add another 5-10 lbs, and for ABS, even more. Probably the greatest benefit from the light weight is in the ends of the boat. With so little weight in the ends of the boat, even an 18-foot kayak behaves wonderfully in a sea, and isn't such a bear turning. But then I like kayaks that don't track as well as most people seem to like.

Regarding glues, I used to use thickened epoxy for the batten-plank joints, but lately I've been avoiding epoxy to a large extent and going with either a polyurethane or basic woodworker's glues. I get the joints fitting tight enough by beveling the outside surfaces of the battens, so I don't have to thicken the glue to stay in the joint. That makes for a stronger joint anyway, so it is most desirable--more wood in the boat, and less glue. Once the planks are in place, whatever gap might be left between the edges of the planks I squeeze more glue into to be sure they're filled, then sand over the outside, which adds sanding dust to any exposed glue, thickening it in place. Mostly the advantage to this method is that it is a very quick and easy way of finishing the seams.

I've been following a lot of the discussions on this forum and others, and have come to the conclusion that sealing everything within thick layers of epoxy just isn't necessary. I think the most important means of preventing rot is to maintain whatever finish you use--not the original choice of finish. I expect a varnished boat that is cared for and re-varnished every 2 or 3 years will last longer than a thickly epoxied boat that isn't checked regularly and resealed. That's my philosophy in any event. I don't worry much about abrasion because we don't drag our boats up and down the gravel beaches, we get our feet wet. But even if I had a nice production glass or kevlar boat, I don't think I'd drag them around either. My 18-foot sea kayak was built in 2001 and has had a lot of use from Maine to Florida, and is still in great shape with no fiberglass in it.

BTW all, I'm looking to either build or buy a 2-wheel dolly for this boat--any recommendations? I'd like something smaller and lightweight.

ZZ
04-30-2016, 06:28 PM
Some, if not all, of Hobie's well assemblies have a pair of holes to accept vertical dowels on their own dolly design. You could do something similar at the central frame on your hull, a block of wood inside against the frame, two holes into it from below to take dowels on your own dolly. Just a light strap to keep the boat from bouncing too much on that unpaved path to the water. I found that keeping the dolly located in relation to the hull could be a pain if just relying on a strap cinched around the hull. Then again, your design of that frame looks like that's what you had planned for, lots of compression at that point. And the larger diameter wheels you use, the easier the manouvering on rough ground. Of course, regardless of what you have in mind for wheels, one is cheaper than two; is your rudder mount beefy enough to support the hull on a single wheel? Seems to me you had a handle on the bow of your solo boat. Options, options. Hot air balloon anyone?

smallyachtsailor
04-30-2016, 06:53 PM
Some, if not all, of Hobie's well assemblies have a pair of holes to accept vertical dowels on their own dolly design. You could do something similar at the central frame on your hull, a block of wood inside against the frame, two holes into it from below to take dowels on your own dolly. Just a light strap to keep the boat from bouncing too much on that unpaved path to the water. I found that keeping the dolly located in relation to the hull could be a pain if just relying on a strap cinched around the hull. Then again, your design of that frame looks like that's what you had planned for, lots of compression at that point. And the larger diameter wheels you use, the easier the manouvering on rough ground. Of course, regardless of what you have in mind for wheels, one is cheaper than two; is your rudder mount beefy enough to support the hull on a single wheel? Seems to me you had a handle on the bow of your solo boat. Options, options. Hot air balloon anyone?

Some good ideas there yes, I'll have to think about them. I have no worries about compression with this boat, it's already extremely stiff and strong. I should be able to strap a dolly anywhere along it's length. I use one wheel on my trimaran, locking in the gudgeons where the rudder goes, but I find it a bit awkward with one wheel. I'd like two wheels on this, and probably closer in toward the center of the boat to take more of the weight. I was also thinking of the Hobie idea that maybe I should make something that slips up inside the rear drive mount hole from underneath--thanks for reminding me. As a matter of fact, while I write this I may be deciding that's best. I already have comfortable wood handles made for this boat, as I did on last year's boat. I have time to ponder.

I do like the idea of a crew in a hot air balloon following me around the rest of my life lifting anything heavy that needs lifting at a moment's notice...

Jbtate3
05-01-2016, 09:31 AM
Glad you're enjoying the thread.
BTW all, I'm looking to either build or buy a 2-wheel dolly for this boat--any recommendations? I'd like something smaller and lightweight.

Chesapeake Light Craft has plans for a kayak cart. I built one and use it several times per week. I built mine by looking at their site.
Link: http://www.clcboats.com/shoptips/fitting_out/kayak_cart.html

upchurchmr
05-01-2016, 10:59 AM
Just found this thread, I'm mostly replying so I can keep track of the rest of the build.

I'm very impressed with lots of your design detail, and the craftsmanship is first class.

However this is very irritating to see a 39# boat in the same length as my 45# stripper. I'm going to have to rethink some things.

Please keep it coming.

Marc

smallyachtsailor
05-01-2016, 11:22 AM
Just found this thread, I'm mostly replying so I can keep track of the rest of the build.

I'm very impressed with lots of your design detail, and the craftsmanship is first class.

However this is very irritating to see a 39# boat in the same length as my 45# stripper. I'm going to have to rethink some things.

Please keep it coming.

Marc

Thanks for the kind remarks. I know that batten-seam construction isn't very common in kayak-type boats--maybe I'm about the only one doing it. Most people assume my boats are CLC designs that are stitch-and-glued. But so far I have yet to find a lighter method of building--other than glued lap as I mentioned, which perhaps is equivalent. I've only built 12-foot canoes with glued-lap so I can't compare directly--its a different beast. Of course there's the ultralight skin-on-frame boats, but that's a whole different thing. I would like to build one of those sometime. This build is going to be much beefier, since it's a two-person, hence my interest in two-wheel dollies. BTW I seached my storage area and found an old two-wheel dolly I made years (decades!) ago and forgot I still had. It'll do until I get something nicer made or bought.

smallyachtsailor
05-01-2016, 11:47 AM
Today was a big day. The bottom is ready for painting, which will have to wait till after the upper strakes are varnished, so it's time to turn the boat over. I can't stand back much in the basement for a photo, so the transom looks much larger than it really is in proportion to the rest of the boat. It's really only about 13 inches wide, whereas the maximum beam of the boat is about 30-31 inches.

http://wildlifeofct.com/wbfphotos/1862sm.jpg

The hull will be dark blue below the lower rubbing strake, with the top strake varnished. There'll be another cherry rubbing strake at the sheer, which has to wait for the decking before it can be added.

http://wildlifeofct.com/wbfphotos/1865sm.jpg

Bow view shows the cherry lower rubbing strake and keel strips well. Of course the perspective makes it look tall and narrow. I did design this hull to handle rough seas, and of course it'll have bow and stern WT compartments. The bow should cut through waves quite well, but with enough flam to lift it and not worry at all about diving.

http://wildlifeofct.com/wbfphotos/1866sm.jpg

It's nice to turn a boat over and see that the interior doesn't need a huge amount of touching up. Some glue blobs here and there, and pencil marks to remove. The cockpit will get carlins added in the frame notches, and side decks about 4" wide.

http://wildlifeofct.com/wbfphotos/1867sm.jpg

St.J
05-02-2016, 02:55 AM
SYS,
Thoroughly enjoying your thread. Thanks for all the details.
Your use of batten seam construction sent me back to my books. I've never seen it in the flesh; it's a really interesting method that deserves more attention.
I'm fascinated by your design and hoped that you could give us more details about how you designed and drew it.
Looking forward to seeing it in the water.

My only contribution is a caveat about the Hobie style dollies. We use a slot in trolley on our Hobie Tandem Island. It's a great design until you're trying to get the balloon tyres under the boat in the water! Hard to do single handed even on dry land. That said your boat is going to be a lot light than a HTI. The two wheel strap on designs (which I'm sure you've used on sea kayaks) are much better with a lighter boat.
St.John

keyhavenpotterer
05-02-2016, 03:43 AM
I have been looking for a Mirage Drive design for ages. Would it be possible to somehow obtain the drawings for the single or the double? I would be hugely appreciative.

Brian

smallyachtsailor
05-02-2016, 07:58 AM
SYS,
Thoroughly enjoying your thread. Thanks for all the details.
Your use of batten seam construction sent me back to my books. I've never seen it in the flesh; it's a really interesting method that deserves more attention.
I'm fascinated by your design and hoped that you could give us more details about how you designed and drew it.
Looking forward to seeing it in the water.

My only contribution is a caveat about the Hobie style dollies. We use a slot in trolley on our Hobie Tandem Island. It's a great design until you're trying to get the balloon tyres under the boat in the water! Hard to do single handed even on dry land. That said your boat is going to be a lot light than a HTI. The two wheel strap on designs (which I'm sure you've used on sea kayaks) are much better with a lighter boat.
St.John

St. John,

Glad you're enjoying the thread. Over the years I've found it interesting that so few use batten seam construction for small boats. Maybe stitch-and-glue has gotten so popular that it's just been pushed aside. Although I don't recall the exact reasoning, I think I may have adopted it because I really wanted to avoid using fiberglass and S&G. I recall trying some of CLC's early kayaks (the Cape Charles comes to mind) and thinking I could design a much better shape by building on frames and battens, especially around the forefoot. Obviously the use of battens at the seams avoids the use of stitching and fiberglass. I remember the Cape Charles and some other kayaks back then had bottom panels that carried too flat into the ends and tended to pound in any kind of waves.

I'm not sure what details I might be able to relate about designing this boat. As with most boat designers, I steal most of my ideas and maybe at most put them together in a bit different way. It's rare to see anything truly new in boat design. My design process is pretty straightforward. I look around at similar boats, then the new boat takes shape in my head, usually over a period of months. At that point the design is pretty much set. Once I'm satisfied that I've got the design I want, the rest is pretty much busy-work. I sketch it out on graph paper (I included that near the top of this thread), then from the sketch, draw it out larger and fair the lines. From that I loft the frames and stem full-size, then build. I don't use any of the boat design software; I have a drawing board. I've tried a few hull design programs but have never taken to using them.

With this boat in particular, I thought a lot about the characteristics of the Hobie mirage drive. I knew I wanted a boat a bit wider and more stable than a sea kayak because your legs are up in the air--the CG is higher and you're not bracing your knees under the deck. For last year's boat--my Wood Duck, I decided on single-chine because I thought I could use a bit of dynamic lift from the flatter bottom and a bit more buoyancy aft to keep the stern from settling at speed. This worked out fairly well, but I realized that I should have optimized for cruising speed rather than top speed. So this time I was shooting for 4-5 mph. I designed this hull with low wetted surface and a fine run, not really worrying about the stern settling at speed. Basically tuning it for the least drag at 4-5 mph, without making the boat too narrow. I doubt it'll make much wake at that speed, so most of the drag will be the unavoidable drag from the wetted surface. I think the top speed on this hull should be around 7 mph, but we'll probably only hit that for short periods to show off. No point in designing for top speed.

While I'm designing the hull, I also have to consider how the boat is constructed. First I assemble the upper strakes and battens, and tape them together bow and stern, then bow them apart and insert the frames. All of this done upside down on sawhorses (or in this case a long table). You don't really need much in the way of plans to build a boat in this manner--it could be built simply "by eye". But I like to know ahead of time where I'm going.

So the curve of the sheer results from bending these side panels apart. Before bending, the top edge of the side panels is actually a straight line. Drawing up the design on paper revolves around "predicting" the resultant sheer correctly. If I get this right, everything falls into place with maybe only a little tweaking: the frames all fit right, and the rocker and hull shape turns out as predicted, and the boat actually ends up looking like the plans.

I hope that's something of what you were looking for with respect to the design.

I'm continuing to think about a dolly. I was thinking I could stick it up through the rear drive mount hole, but then thought I'd be better off with a generic two-wheel dolly that I could use on any boat. Sounds like you've come to the same conclusion, so maybe I'll stick with that. This boat will definitely be heavier than my previous boats, but nonetheless, fairly light compared to many.

Thanks for the comments.

Paul Denison
05-02-2016, 08:25 AM
This has worked well for me, and it's cheap. http://www.amazon.com/TMS-CART-CANOE-KAYAK-KY001-Carrier-Trolley/dp/B0082365AQ/ref=zg_bs_10208138011_1

smallyachtsailor
05-02-2016, 08:33 AM
I have been looking for a Mirage Drive design for ages. Would it be possible to somehow obtain the drawings for the single or the double? I would be hugely appreciative.

Brian

Brian,

I appreciate the interest in my designs. I've had a lot of people ask me about them over the years, but aside from designing some boats for a few close friends I haven't taken it beyond being simply a hobby. And frankly, given today's lawyer-ridden society, I'm kind of afraid to do so without first at least forming an LLC. But doing that, and finishing out the designs themselves to the point where others can understand them, involves a lot of additional work. And my health has always been an issue too--I often don't have the energy. A Canadian company even wanted to kit my trimaran design, but it would've involved more time and effort than I could manage. Perhaps some of the forumites could chime in on the legal issues of boat plans--maybe I worry too much about that? Seems to me that forming an LLC would be a minimum step though to protect yourself.

smallyachtsailor
05-02-2016, 08:36 AM
This has worked well for me, and it's cheap. http://www.amazon.com/TMS-CART-CANOE-KAYAK-KY001-Carrier-Trolley/dp/B0082365AQ/ref=zg_bs_10208138011_1

Thanks for the recommendation--I like the price. Maybe I'll give that one a shot.

ZZ
05-02-2016, 03:17 PM
While everyone is picking your brain I might as well chime in. What's your experience/opinion of the various Mirage models? I don't find any explanation of the different models in their catalog. Is the V2 simply the latest update in the Mirage evolution or do different versions have different charachteristics?

I'm refering to the drive units here, not Hobie's boats.

St.J
05-02-2016, 04:19 PM
Thanks for your reply. Much appreciated.
Best of luck with the rest of the build. It's a very neat job.
St.John

smallyachtsailor
05-02-2016, 06:21 PM
While everyone is picking your brain I might as well chime in. What's your experience/opinion of the various Mirage models? I don't find any explanation of the different models in their catalog. Is the V2 simply the latest update in the Mirage evolution or do different versions have different charachteristics?

I'm refering to the drive units here, not Hobie's boats.

Good question. Here's what I know, although I may not have it all exactly right. V2 is a second generation--an update that happened some years ago, I don't know exactly when, where they changed some of the parts to improve the unit. So to order some replacement parts, you now need to specify V1 or V2. I think my first unit which I bought a few years ago is a V2 ST Turbo. There are three fins available, the Standard, the ST, and the ST Turbo. The Standard fins are shorter with rounded tips, and the ST are about the same length (something like 11 or 12 inches) with squared-off tips, and the ST Turbo fins are a couple inches longer (about 14"), also with squared off tips. In the Hobie catalog they refer to these three as "low, medium, and higher gear". I should say that I tried a Hobie boat with the shorter regular fins, and much preferred the longer fins, as did my wife--they produce much more power. I just bought a second drive, and it is still a V2, but has roller bearings, so instead of being a Mirage GT, its a Mirage GTT. GT stands for "Glide Technology", which means it has roller bearings and supposedly operates even more smoothly with less effort. I don't know what my earlier unit has--I haven't taken it apart since it hasn't broken yet, but it certainly is easy and smooth to pedal.

They sent me a catalog, and looking at it, it lists three choices now:

Mirage Drive GT - ST fins
Mirage Drive GTi - iSeries (I have no idea what this is or what "i" stands for--maybe there's a plug for an iPhone? Everything seems to need one nowadays)
Mirage Drive GTT - ST Turbo fins (this is the new one I just bought)

I've read where the "Standard" drive is discontinued...Looking on the Hobie website right now, it looks like only the ST or ST Turbo fins are available--at least on new drives.

Then in their parts section they mention the V2 Comfort (threaded sprocket) and the GT ST (threaded/bearing sprocket), the V2 Turbo (threaded sprocket), and GT Turbo (threaded/bearing sprocket).

What I can make of it is that you need to know which generation (V1 or V2) you have, whether it is the newest "GT" with roller bearings, and which of the three sizes of fins you have.

I hope this helps.



Meanwhile, getting things ready on the boat to seal the inside and then get the decking in place...

ZZ
05-02-2016, 08:57 PM
[QUOTE=smallyachtsailor;4877191]Good question. Here's what I know.............
I hope this helps.

It does, thanks. You basically confirmed my thoughts, I'll go for the GTT - ST Turbo and not be disapointed. I'm currently working on a dual finned version of Harry Bryan's Finboat drive for my punt, the Mirage drive will go in a wherry I'm planning to build over the winter. Trouble is, I can't concentrate on either one, aaaack!

smallyachtsailor
05-03-2016, 01:29 PM
[QUOTE=smallyachtsailor;4877191]Good question. Here's what I know.............
I hope this helps.

It does, thanks. You basically confirmed my thoughts, I'll go for the GTT - ST Turbo and not be disapointed. I'm currently working on a dual finned version of Harry Bryan's Finboat drive for my punt, the Mirage drive will go in a wherry I'm planning to build over the winter. Trouble is, I can't concentrate on either one, aaaack!

I hope we see some pics of your finboat, and a report on how it runs in the water. I've seen them and am curious how well they work. Seems like they'd make the boat wig-wag a lot, especially a short boat. I know Hobie or some aftermarket company has a fixture to mount a mirage drive on the stern of a boat also.

I've always thought a wherry, such as those designed for sliding-seat rowing, would work really well with a mirage drive. I'd always wanted to build a pedal-prop driven boat sometime too, but then the mirage drive showed up ready-to-buy.

ZZ
05-03-2016, 03:19 PM
The few videos I've seen of Harry's design in action show lots of wiggle, "the tail wagging the dog." I'm building a dual opposed fin version that hopefully will provide thrust without the wag. Whether the dual fin works well or not, the Mirage drive is still the way to go as far as I'm concerned, I'm just fooling around to satisfy my own curiosity. I've seen a picture of a stern mounted Mirage drive, I think it was at a gathering in the UK, but I seem to remember reading somewhere that the drive needs a hull above it to work at its full capacity. To me, one of the plusses of the Hobie unit is that it doesn't neccesitate major modification of an existing hull shape in order to be used. You just install the well and a seat and go, nothing hanging off the stern (which adds to transportation problems.)

nedL
05-03-2016, 03:58 PM
Very nice! Nice clean work too!!!! (ahhh, .... maybe a bit too clean. :D )

smallyachtsailor
05-04-2016, 11:56 AM
Very nice! Nice clean work too!!!! (ahhh, .... maybe a bit too clean. :D )

Thanks.

I should apologize for and explain the overly-clean "shop". It's actually not my shop, its the basement outside the door to my shop. Here's the hidden mess under my bandsaw inside my shop:

http://wildlifeofct.com/wbfphotos/1871sm.jpg

I don't have room in my shop itself to actually build a boat, and outside the shop we have two large automated dustmops:

http://wildlifeofct.com/wbfphotos/1872sm.jpg

So we try to keep the dust down before they do the mopping.

The cockpit carlins are in, so just a couple breasthooks and I think I'll be ready to seal the inside of the hull in preparation for putting the decks on:
http://wildlifeofct.com/wbfphotos/1882sm.jpg

ZZ--thanks for the PM with the links to articles on some of the drive units out there--interesting stuff.

I know Hobie makes some claims about the mirage drive that perhaps are not entirely substantiated, but I went with the mirage only after I actually tried one out myself. Last summer I got a lot of use out of my Wood Duck with the single drive, and I loved it. I think I only used my sea kayak once all summer, and that was mostly out of guilt for leaving it hanging in the garage. Perhaps the only drawback I found with the mirage drive was that it can collect weeds, even the smallest of which will slow you down noticeably. But it only takes a minute to pull the drive up and remove the weeds, and then with the extra speed from the mirage drive, I can then easily make up the distance to my friends in their sea kayaks.

In shallow water I could keep moving by not sweeping the fins in a full arc--I could still move reasonably well in maybe only a foot of water. In most cases I could simply get the boat up to full speed and zoom over a shoal and back into deep water. Even if the sea kayaks with me cut the corners through shallow water, with my extra speed I could always catch up easily.

I did find one curious characteristic of the mirage drive while pedaling offshore in rough water. When you're pedaling the drive, it acts as a powerful stabilizer. While my friend's sea kayaks were bouncing around in the chop next to me, I realized my boat was holding incredibly steady as long as I pedaled. If I stopped pedaling and held the fins pointing straight down, they acted much like a sailboat centerboard and still had a somewhat lesser steadying effect. And then when I folded the fins full up against the bottom of the boat it started bouncing around as you would normally expect. I also noticed the boat went into the wind seemingly effortlessly compared to a kayak. I normally have used an unfeathered kayak paddle though, and that probably accounts for most of the difference. Of course the biggest advantage of a pedal drive is that your legs don't wear out nearly as fast as your arms.

smallyachtsailor
05-07-2016, 01:55 PM
A few coats of polyurethane on the inside already, thanks to my wife. She's better at varnishing than I, and was even asked at the Seaport to refinish the Morgan's wheel before it sailed to Boston. I'm a lucky guy.
http://www.wildlifeofct.com/wbfphotos/1883sm.jpg

I really like the look of contrasting wood. Unfortunately the cherry I'll use for rubbing strakes and cockpit and hatch coamings won't turn dark soon enough for the WBS in June--seems it takes about a year to really darken and give a nice contrast with the varnished okoume plywood. So far I've used okoume ply, pine (yes, that's right, pine) for the battens, cherry for trim strips, maple for the rudder stock, and mahogany here and there. For this kind of boat that's only in the water for a few hours now and then, I don't tend to have any problems with using even the "non-boat" woods, as long as they're all kept sealed with regular maintenance.

Today I finished putting the rudder assembly together (below). I've simplified the design from last year's, which I had just a bit of problem with--the rudder would stick a bit between the wood side-plates--so I eliminated that aspect entirely. This one has a screw adustment with the aluminum plate rudder offset on one side of the rudder stock. Simple. Hopefully it'll work fine. You can tighten it down till there's almost no play, and yet the rudder swings up and down easily, which will be done with a cord leading along the port-side deck also. As with last year's, I'll steer with a pole along the port side-deck. Starboard side-deck will be reserved for the double paddle used to get in and out of the launch.

http://www.wildlifeofct.com/wbfphotos/1886sm.jpg

...still on schedule...I think...

ZZ
05-07-2016, 10:56 PM
Looking great and still plenty of time. Sunlight will darken that cherry trim, they're promising some soon, send the boat out in the yard for tanning sessions. Have you figured out just where the drive wells will be located yet or are you going to float the hull first and both hop in for a photo op?

smallyachtsailor
05-08-2016, 09:47 AM
Looking great and still plenty of time. Sunlight will darken that cherry trim, they're promising some soon, send the boat out in the yard for tanning sessions. Have you figured out just where the drive wells will be located yet or are you going to float the hull first and both hop in for a photo op?

No time for tanning sessions, and it's a bit of work to squeeze it out the door. All the drive and seat positions were calculated early on in the initial sketches along with displacement, CB, and CG. I even worked it out to balance with tall/short/heavy/light pedaler combinations. The frame positions are arranged from all the calculations so they won't be in the wrong spots. Hopefully it all works out.

Five major things to do--deck, hatches, cockpit coaming, drive wells, seats--so at one week for each I should be done in time if all goes well. My wife is skeptical.

Working on an 11.5-foot laminated, slightly bent steering pole right now. Sitka since I had a bit lying around and it's light and stiff. I promised my wife she would be able to steer from the front seat.

smallyachtsailor
05-16-2016, 08:34 AM
Here's the steering pole being laminated from sitka--laminated because I needed it curved to match the curve of the deck edge--it'll be on top of the deck alongside the cockpit on the port side:

http://wildlifeofct.com/wbfphotos/1888sm.jpg

The bow section, the hardest of the four deck panels to install because of the severe camber, is clamped and nailed in place with small brads. The straight "V" cut at the cockpit is only the initial cut to fit the panel--it will be trimmed to a curve later.

http://wildlifeofct.com/wbfphotos/1890sm.jpg

And the stern panel--much easier with much less camber. The brads will be removed and the holes filled merely by squirting glue in, and sanding lightly while the glue is wet--the holes nearly disappear.

http://wildlifeofct.com/wbfphotos/1891sm.jpg

...and the side panels--no brads needed here:

http://wildlifeofct.com/wbfphotos/1892sm.jpg

All the deck panels in place and trimmed, and the upper cherry rubbing strake is being installed:

http://wildlifeofct.com/wbfphotos/1893sm.jpg

More brads along the edge to hold the rubbing strake in place while the glue dries:

http://wildlifeofct.com/wbfphotos/1894sm.jpg

smallyachtsailor
05-16-2016, 08:36 AM
The lifting handles at bow and stern are in place, and the holes cut for the hatches. Next, the cockpit and hatch coamings:

http://wildlifeofct.com/wbfphotos/1895sm.jpg

Five weeks or so to the WBS, still on schedule...no major problems so far.

smallyachtsailor
05-19-2016, 03:07 PM
I've already got the plywood parts of the hatch and cockpit coamings in place, so now there's a lot of strip-work to do:

http://www.wildlifeofct.com/wbfphotos/2239sm.jpg

Here's the forward hatch before any stripwood is in place. I've used this type of hatch (what I call a "turret" hatch) in a bunch of my boats and it's worked very well and is fairly easy to build. I developed it about 15 years ago after a number of iterations.

http://www.wildlifeofct.com/wbfphotos/2240sm.jpg

Never enough clamps:

http://www.wildlifeofct.com/wbfphotos/2245sm.jpg

More clamps. These are the strips for the hatch coamings and hatch covers being bent inside a bucket of about the right diameter (1 foot). I just soak them first for an hour in a wallpaper tray, then they usually bend fine without breaking.

http://www.wildlifeofct.com/wbfphotos/2246sm.jpg

Here's the first pine strip clamped around the rear hatch coaming:

http://www.wildlifeofct.com/wbfphotos/2247sm.jpg

Cherry and pine laminated around the cockpit coaming to create a striped look on the edges. The hard cherry wears very well also and protects the lighter, softer pine.

http://www.wildlifeofct.com/wbfphotos/2251sm.jpg

At this point I think I'm getting ahead of schedule...which is good.

smallyachtsailor
05-29-2016, 10:28 AM
It's almost June and a few weeks to the Woodenboat Show, but things are going fairly smoothly. Here's the forward hatch coaming finished, and the thingumies for holding the bungee cord that will hold the hatch cover down. Many years ago now, Nick Schade had similar hold-downs on a kayak of his, and he was happy to let me borrow the idea. I've liked the look and function of them so much I'm still using them. The hatch hole is 12" in diameter which seems to be enough to swallow a small backpack and most of the stuff we take to the beach.

http://www.wildlifeofct.com/wbfphotos/2257sm.jpg

Here's the rear hatch with the cover in place. Closed-cell foam weatherstripping around the underside of the hatch rim seals it, with pressure from the bungee cords pushing down. These hatches generally seal so tight that I once had to drill a tiny airhole in one compartment because it was not only water-tight, it was air tight. Setting the boat in cold water caused the air inside to contract and oil-can the deck downward.

http://www.wildlifeofct.com/wbfphotos/2260sm.jpg

Bow view with the hatches and cockpit coaming finished. The hull is now on horses so it's lower, and clamped upright in preparation for working on the drive boxes.

http://www.wildlifeofct.com/wbfphotos/2263sm.jpg

I'm very happy with the lines. I was pleasantly surprised when I moved it off the higher table onto the horses. I thought it'd be heavier than it is--about 50 lbs so far--still not bad for a 17-footer for two people. I was expecting 10 or 15 lbs more at this point. This is heavy compared to most of my previous boats, but I had decided to go for more strength from the start, mainly to make it easier to get in and out of the cockpit without worrying about where you can grab or put your weight.

http://www.wildlifeofct.com/wbfphotos/2264sm.jpg

Now the drive boxes. Here's the hole and all the supports you really need already in place. The rest of the box stiffens things and keeps the water out. The drive rests on four points--on the keelson fore-and-aft, and crosswise on each end of the axle. I actually place the drive unit in the boat to position these accurately, and I use a jig to keep everything positioned properly.

http://www.wildlifeofct.com/wbfphotos/2268sm.jpg

smallyachtsailor
05-29-2016, 10:36 AM
Here's the forward drive box position with the rectangular frame jig in place. It's used (along with the drive unit itself) to position the two axle supports on each side of the drive unit. I've modified last year's drive box a bit to make it simpler with fewer pieces. It'll also allow for a wider range of motion of the built-in leg length adjustment of the mirage drive, something that's not necessary in this case because my seats will adjust for leg length, but it will allow for more options in adjusting seating position.

While I'm busy with the drive units, my wife is varnishing (poly) the upper hull strakes and deck.

http://www.wildlifeofct.com/wbfphotos/2271sm.jpg

Rich Jones
05-29-2016, 10:37 AM
I like it!

Gib Etheridge
05-29-2016, 10:51 AM
Excellent and very interesting thread. Definitely an experienced and skilled builder.

That thing's going to be fast!

ZZ
05-29-2016, 03:13 PM
Looking wonderful! Besides drive boxes and seats, is there anything left? That's assuming the dustmop crew don't interfere with the varnishing crew. Maybe time for a test on the river before the show. See you there!

smallyachtsailor
05-29-2016, 09:57 PM
Looking wonderful! Besides drive boxes and seats, is there anything left? That's assuming the dustmop crew don't interfere with the varnishing crew. Maybe time for a test on the river before the show. See you there!

Thanks much.

After the drive boxes I'll do the seats, but then it's only a few small items: install the rudder and steering pole, both of which I've already made, floorboards, and bungees for the hatches. I think that's about it. Five or six coats of poly on it already, and it'll need a few coats of dark blue paint on the bottom. I certainly hope I'll have time to try it out before the show, its always nice to be able to claim that it does indeed float.

2dogsnight
05-31-2016, 10:20 PM
very impressive design, and very clean fitting build. Absolutely love it !

smallyachtsailor
06-01-2016, 07:58 PM
Here I've got the new drive unit in the forward position, clamped vertically. I'm using it and the rectangular jig to locate the lateral axle supports:

http://www.wildlifeofct.com/wbfphotos/2273sm.jpg

After the drive supports are in, the box gets fitted and glued in place:

http://www.wildlifeofct.com/wbfphotos/2280sm.jpg

Then more bits are added. This view shows some of the locking mechanism on the sides of the box:

http://www.wildlifeofct.com/wbfphotos/2290sm.jpg

If all goes well tomorrow I'll finish the drive boxes. Seven coats of varnish on the outside of the hull now, so that's probably done--except for the blue bottom paint.

BlueCanoe
06-01-2016, 08:28 PM
A few coats of polyurethane on the inside already, thanks to my wife. She's better at varnishing than I, and was even asked at the Seaport to refinish the Morgan's wheel before it sailed to Boston. I'm a lucky guy.
http://www.wildlifeofct.com/wbfphotos/1883sm.jpg



After seeing so many glued lap boats slathered with epoxy on the inside, I was surprised to see one varnished. Could you expand the pros/cons of using varnish instead? It's certainly beautiful and sounds more pleasant than working with goo.

Thanks,

Steve

smallyachtsailor
06-02-2016, 10:49 AM
After seeing so many glued lap boats slathered with epoxy on the inside, I was surprised to see one varnished. Could you expand the pros/cons of using varnish instead? It's certainly beautiful and sounds more pleasant than working with goo.

Thanks,

Steve

I know exactly what you mean. I "slathered" epoxy on the insides of my 12-foot peapods when building them, and I've regretted it ever since.

I think I may have talked about finishes earlier in the thread, but certainly avoiding epoxy has its advantages. After using epoxy (with poly over for UV protection) at times, and polyurethane alone at other times to finish boats, I simply haven't seen a big difference in longevity between the two. Keep in mind we're talking about fairly lightweight boats that are only in the water a few hours at a time, are not dragged on gravel beaches, are always checked for scratches that might go through the finish (and are fixed before the next use), and finally are re-varnished every 2-3 years. I think regular maintenance is the key. Epoxy perhaps has better abrasion resistance, but maybe only because it's a thicker coating most of the time. But it's also a pain to finish and as you noted, usually doesn't look as good as poly alone, although I'll gladly admit that some of the forumites seem to be much better at using epoxy than I am. It also adds more weight--at least in my experience, most certainly if you use glass. I do continue to use epoxy for various joints and bonding around the boat--wherever it works better or is more convenient than other glues.


After years of inadvertantly scraping over submerged rocks, I've found that most scratches do not go through the finish, whether it is epoxy or varnish. They really just mar the finish. Only the worst of them dig through the finish and hit bare wood, and I can only think of a single instance of getting a hole in the boat. In this case it was a submerged pointy stick that punched a 1/8" hole in the plywood, although not clean through. So most of the time, letting the boat dry for a day after using it, and then sealing any scratches (usually I do so temporarily with CA), keeps water away from the wood. Then a light sanding and a new coat of poly every 2 or 3 years.

I guess in a nutshell, epoxy is more work and heavier, so with careful boat handling and regular maintenance, I can get away with polyurethane alone. I don't know if everyone would have the same experience.

Bob

ZZ
06-03-2016, 03:04 PM
How come the new drive box configuration? Is the new drive slightly different or will they be interchangable? I would think the design in your single boat would be easier to manouver around.

lupussonic
06-03-2016, 03:25 PM
I'm loving your work Sir. I like the design and build ideology so much I would suggest you make plans available on WB... I think there would be plenty of people who would buy them, particularly as you have honed the design and tweaked out so many problems along the years. This is excellent.

smallyachtsailor
06-03-2016, 10:26 PM
Thanks so much for the questions and encouragement.

ZZ;

Yes, I have modified last year's drive box a bit. I discovered after-the-fact that the more compact diamond design in the Wood Duck last year didn't quite allow for the full throw (12") of the built-in leg length adjustment of the mirage drive. My wife and I inhabit fairly different elevations above ground, and we had a bit of trouble adjusting the Wood Duck to fit her. This new "boxier" design does allow the full adjustment, and it also is easier to build and has fewer parts. The locks will operate the same though. The seats in this boat, as in last year's, will also slide for leg adjustment, so I think I should be fine in that regard. The new mirage drive is indeed exactly the same configuration as the older one, so yes, they are interchangeable between the drive boxes. To the best of my knowledge all the various models of mirage drives over the years still fit the same way.

lupussonic;

Glad you're enjoying the build. I'm not sure how "honed" this particular design is yet--hopefully we'll test it in a couple weeks--then I'll know better. I don't know what's involved with making plans available through WB. But regardless, I'd like to try the boat for a while to see if I've anticipated every problem or not. Sometimes things that look great on paper or in the shop simply don't work as well as you hoped out on the water, but I guess that's the real test of boat design and construction.

smallyachtsailor
06-07-2016, 01:35 PM
Still making progress this past week between bouts with a stubborn kidney stone. The drive boxes are done--and finished with polyurethane. Here's the rear box with the drive in place. I have the lock mechanism parts finished but don't have them installed yet--they go in the two small holes on each side of the box:

http://wildlifeofct.com/wbfphotos/2303sm.jpg

The pointy end showing the blue bottom. It'll look better once the cherry rubbing strakes darken, which unfortunately takes a long time--won't be dark by the WBS.

http://wildlifeofct.com/wbfphotos/2306sm.jpg

...and the forward hatch in place, without the bungee cords on yet. I seem to have picked a piece of ply with a line of knots across--that's ok. I'm fine with just about any natural woodgrain. Gives it character. Same here, all the cherry strips on the hull and coamings need to darken.

http://wildlifeofct.com/wbfphotos/2308sm.jpg

The lifting handles at bow and stern are mahogany, which matches the cherry strakes well once they darken:

http://wildlifeofct.com/wbfphotos/2310sm.jpg

Seats are started, then some floorboards between the seats and drive boxes--just enough to have somewhere to step into the boat, and then install the rudder/steering pole and bungee cords and it's done. It's nice and warm here now, and the water looks inviting...

tom151
06-07-2016, 02:26 PM
Stop it, you're killing me... some of your pics look more like computer renderings. They're so perfect!
Loving it.

ZZ
06-08-2016, 04:18 PM
Computer renderings wouldn't have the clutter of real life in the background.

cprinos
06-08-2016, 09:50 PM
Looking really good so far. What is the spacing between the two pedal stations? I've got a Mill Creek 16.5 that I have though about converting to Mirage drive, but I don't think I could get two seats w/ legroom for the drives.

chris

smallyachtsailor
06-09-2016, 02:08 PM
Looking really good so far. What is the spacing between the two pedal stations? I've got a Mill Creek 16.5 that I have though about converting to Mirage drive, but I don't think I could get two seats w/ legroom for the drives.

chris

Thanks Chris. After a lot of measuring I allowed five feet for each person, so it has a 10-foot cockpit on a 17-foot hull, with a 4-foot WT compartment in front, and 3 feet WT in the stern. I did a lot of CB calcs too, trying to allow for different height and weight people. I considered making it 18 feet overall, but 18 gets a bit long to handle, either in the water or out. Besides, I was shooting for easy cruising at 4-5 mph, and 17 feet is optimum for that. At that speed an 18 might actually take more effort to pedal since you're mostly talking wetted-surface at that speed.

I'm about 6-1 with extra long legs and my wife isn't, so both the seats and drives adjust. Five feet gives me just a few spare inches of legroom adjustment, and enough so I won't whack the person ahead of me in the back of the head with my foot pedals. I could've saved another foot by making the front station one foot shorter, but that would've limited the boat to one tall person and one shorter, maybe 5' 6" at most.

Last year at the WBS I had a guy from Australia take a lot of photos and measurements of the drive box in my Wood Duck. If I recall right he was going to put a drive in a Mill Creek--a single drive I think. Maybe he's on the forum and can reply? It'd be interesting to hear if he went forward with it. Maybe if you put one drive in and the other is just a passenger? I suspect you probably wouldn't see too much of a difference in speed, but you probably would see more of a difference in effort. Hopefully I'll be able to confirm that within a couple weeks.

Good luck on your CS-17--neat work!

Bob

cprinos
06-09-2016, 03:33 PM
Bob, yes what you are describing is a much bigger cockpit than the Mill Creek, plus at the forward position the person's knees are partially under decking (fine for paddling, not so much for a Mirage). For a single it would work. Looking forward to seeing you finish this one... I've pedaled a hobie tandem island in kayak only mode (no amas or sail) and I think this is a great concept.

Thanks for the note on my CS17. I had to take a couple of years off from building due to work, but have recently been able to resume. I learned after building the mill creek not to give myself a deadline though :)

chris

smallyachtsailor
06-14-2016, 12:10 PM
Ok, back at it after a few days off relaxing in the local hospital. Not feeling well but I'm determined to finish this thing now that I'm so close. I think the boat will be done, now I'll have to start worrying about getting there myself. Hopefully so.

Here's the completed drive box, showing the details of the locking mechanism. I thought some of you out there might be interested if you're planning on trying to install a mirage drive and building your own drive boxes.

It's basically a screw clamp mechanism consisting of a knob at the top attached to a threaded rod that is threaded into an oak stick at the bottom. In the photo below, this lock is rotated out of the way of the vertical channel in the drive box, into which one of the side axles of the mirage drive is lowered.

http://www.wildlifeofct.com/wbfphotos/2311sm.jpg

And here's the mirage drive in place with the locking mechanism rotated into place over the side axle, and screwed down snug. There's a locknut and washer on the threaded rod of the lock just under the top lip of the drive box. This pushes up against the top lip of the box to lock the drive axle down:

http://www.wildlifeofct.com/wbfphotos/2312sm.jpg

Here's a clearer view without the drive unit in the way. I put a steel rod in place of the mirage drive axle:

http://www.wildlifeofct.com/wbfphotos/2314sm.jpg

Hopefully all that makes some kind of sense? It only takes a few twists of the two knobs to loosen or tighten the locks and install or remove the mirage drive.

The rudder and steering pole is finished and on the boat:

http://www.wildlifeofct.com/wbfphotos/2318sm.jpg

Here's a finished hatch with the bungee cords holding it down. Closed-cell foam weatherstripping under the edge of the hatch cover seals it. You can see the curved steering pole on the left, and also the thinner black cord to raise and lower the rudder.

http://www.wildlifeofct.com/wbfphotos/2320sm.jpg

The seat frames are half finished, and it's only them and two small patches of floorboard left to do...9 days left.

ZZ
06-15-2016, 11:07 AM
The boat show will be MUCH more relaxing than any hospital ever was, hope you're feeling better. The boat is looking great, excellent job.

smallyachtsailor
06-19-2016, 10:00 AM
The boat show will be MUCH more relaxing than any hospital ever was, hope you're feeling better. The boat is looking great, excellent job.

Thanks ZZ.

I was about 2 weeks ahead of schedule a few weeks ago, but now I'm back to just finishing in time if I have no more rude interruptions. I don't know if I'll manage to get out to try it before the show, but I still hope to at least once.

I have the seat frames finished and today I'm putting the seat slides in the boat. The seats will be canvas stretched over these frames.

In the meantime I have discovered a new building rule: "Measure twice cut once" is the usual rule, but it becomes "measure three times cut once" if you're on pain meds...and check four times that you don't have two lefthand parts instead of a left and right.

I've stolen the seat geometry from my recumbent trike so I can be sure its just right for pedaling. It worked well in last year's Wood Duck so no sense in changing it.

http://www.wildlifeofct.com/wbfphotos/2321sm.jpg

After the seats, just two small patches of floorboards, if I get to them before the show.

ZZ
06-19-2016, 07:25 PM
Recumbent trike? Is that the tow vehicle?

smallyachtsailor
06-21-2016, 08:01 PM
Finished!

Tomorrow we see if it'll fit out the basement door into the garage. If not I'm getting a new 36" wide basement door...

I'll post more photos once I get it out in the sun. See you at the WBS--looks like good weather for the weekend.

smallyachtsailor
06-22-2016, 01:30 PM
Ok, it fit out the door with only an inch or two to spare. Three months to build and it's done. Off to the show tomorrow:

http://www.wildlifeofct.com/wbfphotos/2331sm.jpg

http://www.wildlifeofct.com/wbfphotos/2356sm.jpg

http://www.wildlifeofct.com/wbfphotos/2339sm.jpg

http://www.wildlifeofct.com/wbfphotos/2348sm.jpg

http://www.wildlifeofct.com/wbfphotos/2373sm.jpg

ZZ
06-22-2016, 03:01 PM
In the sunshine and no chainsaw needed, excellent! Looks loooooong in that last shot. Will you be doing the morning TSCA excursions on the Mystic River?

smallyachtsailor
07-06-2016, 10:25 AM
Finally got the boat out last night and it floats! We took a short cruise down the Mystic River against the incoming tide. I didn't have a gps or camara onboard (I like to keep shakedown cruises simple with no distractions) but it handled much like last year's single, and seemed to be of similar speed (4-5 mph cruise, maybe 7ish top speed). I'm sure I'll get a gps reading sometime. My wife and I have never owned a double so this is a new experience--more weight but more power. For short sprints we got a pretty good bow wave (in addition to the normal stern wave) going. I expect with the extra drive that hull speed is easily attainable--which should be somewhere around 7-8 mph. It floated about where I'd calculated, right up to the lower rubbing strake at the bottom edge of the varnished side--so my math still works.

Some minor adjustments in the seats and the boat should be set. Now for a break in building and some time spent outdoors instead of in the basement.

Thanks to all those who followed this thread and stopped by at the WBS...

St.J
07-06-2016, 01:12 PM
Congratulations. Looking forward to seeing it fly.

Jay Greer
07-07-2016, 07:21 PM
I tip my hat to you sir! Excellent job both on design and construction.
Jay

smallyachtsailor
07-11-2016, 09:32 PM
Thanks for the kind words....

My wife and I just went out and did about eight and a half miles. The seats, after a few minor adjustments, are very comfy. By GPS, we easily maintained 4 mph against the incoming tide in the Mystic River, so 4 or 5 mph is an easy cruising pace. We topped out over 6 mph without really pushing it to the limit, so I think 7 or so mph should be doable (the 6+ mph was also against the incoming tide). Boat wakes and small waves were all we encountered because it was a north wind day and pretty calm out in the sound, but the boat behaved as expected. We even purposely ignored boat wakes and let them hit us in the flank and barely even got splashed.

I made one of those poles that extends out the side of the car for loading it on the cartop one end at a time, and used a homemade 2-wheel cart to run it to the water's edge, so I only had to lift half the boat at a time--at most. Easy. Overall the boat behaves and performs pretty much as expected.

What next?

Dryfeet
07-16-2016, 05:59 AM
Thanks for the kind words....

My wife and I just went out and did about eight and a half miles. ...Overall the boat behaves and performs pretty much as expected.

What next?

More VIDEOS, of course! (I'd REALLY like to have something similar myself. My wife and I enjoy the Hobie but blue plastic boats erode my self esteem....)