Building a Wharram Hitia 17

[kharder]

For the past several years I've wanted to build a wooden boat and my friend Cam has been sitting on plans for a 17' beach cruising Wharram catamaran. We eventually realized this and decided it was time to built a boat together. This will be his build and his boat, but I will be documenting for posterity.

I haven't seen many threads on Wharram cats around here so hopefully this can serve as a reference. I'll be cross posting to both this thread and our blog as we go.

It wouldn't be a build thread without a picture so here is the design:


We hope to splash in time for next season, wish us luck!

[yesiam]

Great -- looking forward to this build and more pictures.

[kharder]

To make the production work with the good plywood go faster we will be using a router and templates. Another benefit will be using the templates to visually plan our cuts on the expensive ply so there is as little waste as possible and if we ever want to build a sister-ship, we'll have a head start.

Earlier in the week I carefully marked out the measurements for the bulkheads and beams on cheap 1/4" ply using a 4 foot drywall square. This was a lot of fun and you start to get a sense of the scale of the boat. The hull shape is pretty simple so no complex lofting here.



We used a scrap of plywood as a batten to draw the curved sides and tops. Admittedly, plywood is not the best batten material, but it worked out ok. Then it was time to finally make some sawdust.



Here Cam is cutting one of the bulkhead edges with a circular saw set just a bit deeper than the plywood thickness to make following the curve easier.



With all six bulkheads roughly cut it was starting to get dark. We set up the bench sander and got one template finalized by flashlight before the mosquitoes and darkness got the better of us. Of course, we still don't have anything that will be part of the actual boat but it feels good to have finally started.

Tonight: finish the templates

Saturday: pick up the marine ply and lumber, cut bulkheads and hull sides, start epoxy coating.

Sunday: resaw lumber for stringers, bracing, keel, etc., glue hull panels together

[dirtsailor]

I've always liked this particular Wharram. I've wasted many a good work hour looking at the photos and watching the videos on YouTube Looking forward to following this build!

[kharder]

Last night we made a few more templates including the fore and aft stems and the rudders. These parts are shown with full size patterns on the plans. You can check for paper expansion with a few measurements, some of which were pretty off ans some were right on. Makes you wonder about the drawing accuracy, but we tried our best to get them right.

The outline of each part was marked with a nail into the plywood. Then it was a game of connect the dots and cut them out using the circular saw.



Some areas like the handle at the top of the stems you just have to free hand until it looks right. Here you can see our pencil lines following the nail marks as well as some improvisation.



We're going on the theory that if it looks right it is right. Should be a big build day today so more progress to follow, check out the blog for more photos.

[peterchech]

looks like a fun project!

[JimD]

This will be fun to watch. Thanks.

[kharder]

Saturday started with a run to the lumber store at 7:30am and ended 12 hours later with all the hull panels and bulkheads cut and lumber sawn to dimension. But in our haste to get as much done as possible we also cut twice as many bulkheads as needed. The extra bulkheads can be salvaged for a lot of small parts, but we'll need at least one more sheet of 4mm ply, maybe two.

Everything began by laying out two sheets of the 4mm okoume plywood end to end and marking out all the measurements for the front and rear hull panels.



It took some double checking to get the outline and bulkhead locations to all agree, but pretty soon we had a batten through all the marks and could see hulls taking shape. Then it was time to cut out the hull side panels and clean them up to serve as a template for the marking the rest. We set up a temporary frame on the deck using the douglas fir boards that would eventually become the keels and stringers to slide the panels by the sander. Once the shape was close we finished by hand with a sanding block right to the pencil lines.



Next we used the first set of hull panels to mark and rough cut the other three pairs. We didn't want to waste any plywood (the irony!) by mixing up which sheet had been used for fore or aft panels so we laid out the bulkhead templates based on the layout guide in the plans and cut them out as well. Unfortunately we marked them out on all eight sheets instead of the four sheets required.

Lesson learned - if it's hot and you're tired and in a hurry to make progress, you're likely to make mistakes. We slowed down substantially after we realized what we had done and made sure to re-consult the plans at every step.

Next we took a break from the plywood and started to re-saw the douglas fir into the 3/4" x 1/2" keels and 1" x 1/2" stringers. Here you can see the grain spacing on a 1" wide strip.



By the time we were done re-sawing it was time to call it a day and to clean up the small mountain of sawdust under the table saw.



Up next, routing the hull sides and lots of epoxy coating.

As always, see the blog for more photos.

[kharder]

So after a very busy day of cutting and routing the plywood pieces, here is where the project stood on Sunday morning. Six pairs of bulkheads with their corresponding templates, four bow panels, one pair of hull panels trimmed to final shape and three pair of hull panels roughly cut.



I wish we stopped to take photos of the next part because it was kind of clever, but i'll describe it instead. In order to hold the good hull sides to the rough cut pieces during the routing we used a staple gun around the edges instead of two sided tape like we had been using on the bulkheads. This turned out to be very quick and stable and the bottom edges are going to be heavily epoxied and fiberglassed anyway because of the stitching later on.


After the SNAFU with cutting out extra bulkheads we took the time to lay out all the panels on the lawn and identify which sides to determine the inside and outside for each piece. That meant it was time to break out the 5 gallon jug of West epoxy and start coating. Every internal surface gets two coats of epoxy hot on hot so that they will bond chemically.



After the first coat the panels were moved to the shade to cure until tacky to the touch. The timing worked out perfectly so that after we gave each of the eight panels one coat, the first was ready for the second coat.



After round two of epoxy the panels were brought down to the basement to dry over night. We didn't have time to do the bulkheads so those will have to wait for another day.

[kharder]

The hull panels have been drying in the eves of the basement and are just itching to be sanded and glued together.



Over the week I made some steady progress coated a couple of bulkheads a night after work. Now all the bulkheads are covered on one side. By next weekend they should all be coated and maybe have the floor and deck supports glued on as well.



New England is bracing for hurricane Irene. The rain is going to start in a few hours so we can't do much this weekend. One day I'll have a proper workshop and a measly tropical storm won't have to slow me down.

[NomadRip]

At least you have the bulkheads already cut for a sister ship? That's all I've got

[kharder]

That was the first thing that came to my mind as well! I think we'll be able to salvage a lot of small pieces and at least it was the sort of lapse in thinking where no one got hurt.

More importantly, if my friend is going to have a beach cruising catamaran then I'm going to need a beach cruising Sooty Tern pretty soon.

[kharder]

Time to keep this project moving. One of the many tasks between us and stitching up the hull sides is cutting out the stems and rudders. Having learned our lesson cutting out the 4mm panels, we layed out all the templates carefully to conserve as much space as possible and followed the plans exactly. Smile for the camera, Cam.



Hopefully that means we won't have any trouble in the future. Next we used a scrap board with a nice straight edge as a guide for the circular saw to put as clean a cut as possible on the rudder to stem edge while we cut it.



We used the same technique to cut the long edges of all four stems and both rudders. Next we cut out a rectangle that will become the backing pads for the beam lashing points. Had to double check the math to make sure we allowed for the right number of saw kerf widths but it should be just right. Next time the table saw is out we can rip it down to final width and then cut it up into our blocks.

I'd be nice to have everything ready to stitch at the end of the weekend. Not sure if that is doable but it's a nice goal.

[kharder]

It's a beautiful day and I'm long overdue for an afternoon of sailing, but first time to keep moving forward on the Wharram. It seems like a good day to glue the support pieces on some of the bulkheads so lets get to it.

The deck and bulkhead supports are made of the 1" x 1/2" fir we ripped earlier. Each one was measured against the bulkhead and then cut to length. Here they all are labeled and ready to go.



I only have the saw horse space (and motivation) to do bulkheads 1, 3 and 6. The bulkheads and fir strips are laid out and the gluing surfaces coated with raw epoxy then the strips are coated with thickened epoxy and pressed into place. Wharram suggests temporarily clamping with nails, but I'm afraid the fir would split and I don't have any drywall screws short enough so I used staples instead.



Once the glue is firmed up I'll scrape out the excess and probably give the unfinished sides their two coats of epoxy.



My little dinghy is getting jealous of all the attention spend on this new bigger boat, so now I'm off to the beach to take her for a quick sail.

More pictures on the blog...

[kharder]

The deck curve at bulkhead #2 is a full 1" which means that our 1" wide deck supports would be too thin on the ends to offer any support. You see the outline of the 1" support against the curve at the top of the bulkhead here.



I could have just added a strip at the bottom to make the whole piece taller, but I thought i would do something a little stronger and lighter. I actually gave the solution away in the first photo, it's the triangular pieces on the far right. They will fit below the full length strip making the whole piece about 1" thick and orienting the grain properly at the edges. Not as fancy as laminating up a curved support but more than enough for a stitch-and-glue beach cat.


I wasn't sure how to cut this at first, but finally decided to just do it by hand with my new Japanese pull saw. The more I use that saw the more I think power tools are over rated.



And here it is all glued up and again held with staples. Staples aren't the prettiest, but it worked and it's all going to be painted later anyway. Here it is with the glue dried and two coats of epoxy.



One more afternoon of glueing and all the bulkheads will be assembled and coated. I'll trim the top edges on the router table and they'll be ready for stitching into the hulls.

[kharder]

Last weekend, after a nice morning of working on the Hitia's bulkheads, I took my wife out on our sailing dinghy named Tipsy.



The wind was a good 12-14 knots and it was some exiting sailing until we broke a lee board and then very soon after broke the other. That left us trying to sail home (straight upwind) with no foils and making a tremendous amount of leeway. I was very glad to have a set of oars on board to row home, even if they were the dinky 5' pair that came with the boat.



They were just a piece of 1/2" plywood with mitered edges, nothing fancy or efficient so I wanted to make new foils anyway. So now i have two projects moving to the top of the pile for the winter: make a nice pair of foils and finish the pair of 8' oars I have glued up.

More pics of the lee board damage on the blog...

[kharder]

It's been almost two months since we worked on the boat last. Between weather, busy schedules and a bit of burn-out we needed a good break. Yesterday we finally got going again and not only made significant progress but proved that our skills are improving.


Last time we caught a mistake we made in measuring the bow panels using the right measurement from the wrong reference point. As a result we cut the angle too. Here you can see what we cut and the line that is what we should have cut.





So that leaves us with this weird shape for a new bow panel.





A quick go with the Japanese pull saw and here is our new bow panel. We then used this piece to mark and cut the other four panels. We're a little worried about the narrow point breaking when the panels are stitched but hopefully the epoxy will hold it all together





Next, all four panels got two coats of epoxy making sure we had two 'lefts' and two 'rights'. All told it only took 2 hours and we were back on track.

[kharder]

We aren't going to have the weather to epoxy the hull panels, stems, and bulkheads into their final shape until the spring, but we want to get everything stitched and ready to go before tucking them away in the basement for the winter. As soon as both hulls are stitched up and ready we will move on to the beams and mast for the duration of the winter.


We had already shaped the profile of the 1/2" plywood stems with patterns and the router table, but had saved the handles for later. First we used the drill press to create a pilot hole for the pattern bit and then cleaned out the handle. The bottom of the handle is cut to line up with the top of the plywood deck when everything goes together. The other divergence from the plan shape was to draw the front of the handle to flow into the 1/2" tall fir stringer that goes down the middle of the fore deck.





Here is how the rudders and rear stems fit together (the rudders haven't been routed to final shape yet). Wharram uses a unique lashing method instead of pintles and gudgeons which is very clever and light weight. We picked up the idea of over drilling the lashing hole locations and filling with epoxy from Scott Williams' blog and will be doing that on our boat as well.





The plans don't locate the lashing points exactly so we just eyeballed what looked right and marked the center lines on both stems and rudders.





We measure back for the center of the row of lashing holes . . .





and drill out each end with a 3/8" drill bit . . .





then use a coping saw to cut out the slots which are filled with an epoxy and wood flour mixture and set aside to cure. Now when we drill out the lashing holes there will be no way for water to get into the plywood end grain.

[kharder]

The holidays are always a busy time of year and this year was no exception. The hull pieces were tucked away in the basement to hibernate until it is warm enough to continue epoxy work. Our plan was to build the cross beams, mast, gaff and tillers indoors during the winter. No progress on that front yet other than building workbenches long enough for the mast.


In the mean time, here is a small nautical project I made as a Christmas gift - a bellrope!



My father in law lives aboard a trawler and I noticed while visiting that his ship's bell was lacking a nice bellrope. Having just read several marlinspike books I thought this would be a nice opportunity to try my hand at some fancy knot work.


I based my bellrope on this excellent tutorial at Frayed Knot Arts which also has tutorials on ringbolt, hitching, and grafting which are used to decorate the bellrope. The materials came from Marty Combs' website that sells both the hard cotton line and brass thimbles.


I started by picking the general proportions based on a length of around 7" to fit with the diameter of the bell. Here are #1, #2, and #3 thimbles; I chose the #2 for this project.





Then loop strands of #15b cotton line around the thimble making sure the grove of the thimble is full but not too full that there isn't room for the ringbolt hitching. In this case it took three strands. Secure each side with a small constrictor knot to hold things together and mark the ends of the ringbolt hitching. Things are still a bit long at this point but will be trimmed up later once the eye of the bellrope is formed and tightened permanently.





This is what the ring bolt hitching looks like when complete. It is made out of single strands from the cotton line which works out nicely.





Here it is all together with a piece of bamboo skewer to the middle to fill out the six pieces of line into a nice circle and also add some stiffness to the finished bellrope.





To be continued ...

[kharder]

So here is where I left off last time. The eye of the bellrope is done and the central core is made around a bamboo skewer and held tight with constrictor knots and a few strategic drops of super glue.





The next step is to build up the graduated taper with layers called 'pudding'. Each layer is held down with constrictor knots and trimmed. At each change in diameter I added wraps of sail twine to create a taper which will help smooth out the transition when the puddings are covered. A turkshead knot will eventually cover each diameter change to create the stacked cylinder effect in the final bellrope.





Now the core is done and it's time to add the final covering. This can either be hitching or grafting, but I thought hitching would be easier for my first attempt. The hitching is tied in rings of over two hitches, there is a good tutorial here. The slight left twist is from having too many hitches which don't have room to tighten enough for perfectly straight rows.





Here you can see how the circles of hitches cover the 'pudding' layers. At each step down a couple of strands need to be clipped and glued so that the circle of hitches can shrink to the new diameter. It takes trial and error to see how many need to be removed. In this case I tried to match the left hand twist of the first stage.





Unfortunately I don't have a picture with the hitching complete, I was in too big a hurry to put on the turkshead knots. Here are the top three turksheads which cover the transitions from the eye to the hitching and then each step in the pudding. Each one is a slightly different combination of number of bytes and number of passes to introduce some variety.





All that is left is finishing off the bottom of the bellrope which I'll leave for the final installment.

[kharder]

The final step to complete the bellrope is to finish the bottom. This can be done several ways but I am going to use a very large turkshead and a basket weave on the bottom. This was by far the most complicated turkshead I have ever tied and it's a good thing there are YouTube tutorials that you can repeat over and over.


Here is the first complete pass. I had no idea how much line this would take so I cut a huge piece and just managed to not run out after all three passes.





Pass number two complete, one more to go.



And here it is with the third pass and tightened down on the bottom of the bellrope. This turkshead wraps around the bottom edge creating a nice rounded end without being bulky. However this style of ending knot leaves the center of the bottom face exposed.





To dress this area up I put on a basket weave to cover the end of the core and pudding layers before applying the turkshead. This was a little fiddly to get tight but it turned out really nice.





A coat of clear poly-acrylic to keep the salt air off the cotton and the bellrope is done!

[kharder]

You have probably noticed that all of our work so far has been on temporary (and my wife might argue inappropriate) surfaces. Well no more working on the floor, we're going to build some permanent workbenches for my basement.

The first step was coming up with a design by browsing the web to see what other people were building. I wanted to use construction lumber and keep it fairly simple and cheap. In the end I combined several elements from each design to come up with something I liked and then worked out the measurements so the final product would be 24" wide and 33" tall. Here are enough 2x4 pieces cut to length to make three benches which can be moved around the shop.

This joint is one element I borrowed from a design I found online that is pretty simple to make and very strong when the surfaces are glued in addition to screws. The two stacked 2x4s will become a leg of the workbench and the cross piece will support the work surface.




After a LOT of cutting and chiseling I ended up with seven of these pairs of legs. The two five foot benches will use two paris of legs while the eight foot will have three to add more support in the middle. Probably overkill but I want these to be sturdy.




Here is one of the five foot benches coming together. The bottom cross pieces will hold the legs and also support a shelf for more storage.




So here are the structures of the first two benches. The top supports are 2x8s which will give a good vertical surface for clamping boards to plane on edge, etc. You can see how the upper boards will hold the plywood top and the lower boards will form a storage shelf.




See Part 2 for the finishing touches and the blog for more photos ...

[kharder]

While buying the wood for the beams we went ahead and got enough for the mast and sprit as well. All the spars will be made out clear vertical grain Douglas Fir. These are the best sticks I could find in the stack at Hingham Lumber and man are they pretty (at least i think so).





The 2x6s will become the beam tops and bottoms, the 2x4s will become the mast and sprit.








The two halves of the sprit were coated with raw epoxy and allowed to tack up. I then realized that I hadn't turned one board end-over-end to reverse the grain orientation. So one board went very carefully back out of the basement through the bulkhead, spun around in the back yard and put back on the workbench.







The ends are propped up with boards and the middle held down with a paint can to get the right amount of curve based on the plans. The spring back for a two layer laminate should reduce the height of the curve by 1/4 to 1/3 so that has been factored in. The tape method of clamping is adapted from Michael Storer of Goat Island Skiff fame where you clamp then wrap in tape to hold. The tape will support quite a bit of pressure, certainly enough to get a good amount of squeeze out.






Next I put on clamps over the taped sections, not to hold the two boards together, but to align the edges and keep them from sliding. Here you can see how the grain has now been properly reversed to prevent warping down the road.






The next steps when the epoxy dries will be to round over the corners with a router, trim to final length, attach the thumb cleats and start varnishing.

[seedy]

Having owned a Wharram, you're in for a treat when she splashes.

Thanks for taking the time to illustrate several projects at once.

[kharder]

Thanks for the kind words. We're still looking forward to the stage where it looks like an actual boat. In the mean time any progress is good progress.

Any advise to keep in mind while we're building based of your experience sailing a Wharram design? Right now our main concern is keeping the weight down.

[timo4352]

I'm glad to see you're back at it.

[kharder]

A bit more progress yesterday. Wharram uses a foot on the bottom of the mast and cleats on the cross beam to locate and establish the rake of the mast. The mast foot also holds the cleats for the jib and main halyards as well as the mains'l downhaul.


The Hitia 17 uses two layers of 1/2" plywood for the foot, here is the outline for one half drawn out on the plywood. You can see that the top of the cross beam is doubled where the mast steps and that a rounded block is added to the aft face which allows you to hook and then rotate the mast into place.





Here it is cut out including shaping the opening where the down-haul line runs through the foot and back up to gain more purchase when tensioning the luff of the sail.





Next the two halves are epoxied together and clamped while keeping all the edges aligned.



Once it dries it will be ready to glue between the two mast halves during final mast assembly.

[kharder]

Yesterday I rounded the edges on the sprit with a router which means the gluing table is clear so now we can work on the mast. The plans call for a box section with epoxy fillets which is then rounded using the normal progression of 4-sided to 8-sided to 16-sided to round.

The first step is to make the two 'U' shaped halves, insert the mast foot and halyard sheaves and then glue the two halves together. Wharram suggests using screws to temporarily clamp the square pieces onto the larger flat pieces then remove and fill with thickened epoxy. Here is our plan to avoid screw holes showing in the final piece, though we ended up angling the screw to provide more depth.




The last thing we want is for the fir to split so each screw location s pre-drilled with a countersink bit. Here is the bit set for the right depth and the angle we decided to use.



To get the spacing right we used 1 1/2" wide cutoffs as spacer blocks. the square pieces are 1" square so that makes a 3 1/2" diameter mast.



Once both halves were aligned and screwed we could back out the screws, coat epoxy and then re-assemble. It was a long day but getting the spars done will be a huge landmark on the way to sailing this spring.

[kharder]

The mast halves have cured and were run through the table saw with the blade at 45 degrees to get down to eight sides. The mast foot fits into recesses cut into two halves and here is the rough fit.





The next step is to support the inside corners of what is essentially a rounded box section with epoxy fillets mixed with 50/50 colloidal silica and micro balloons. There will be a lot of fillets when we get to the hulls (soon!) so this is good practice.





Filler blocks are used to make the mast solid at the ends where the foot and sheaves are supported. The plans call for 1/2" ply but we had 1 1/2" x 1/2" fir scraps so we're using those instead which should be stronger and lighter. To reduce stress points from the sudden change in stiffness at the filler pieces we used the excess epoxy mix to taper the transition.





When we're happy with all the fillets we leave the mast halves to cure.





The recesses for the foot are done, the recess for the masthead sheaves will be next and then we can glue the mast halves together and put it aside until later for the final finishing.

[AnalogKid]

Those fillets look pretty tidy to me. There's going to be a lot of epoxy in this boat by the time it's done. How were earlier Wharram's built - was it all ply over batons?

[kharder]

I'm not sure how the original Wharram boats were built. Anyone here know?

I've been meaning to read his book before our maiden voyage anyway, maybe I can find out.

[AnalogKid]

I read a copy about 18 months ago that had to be dug out from the central library's basement vaults. I don't remember too many construction details being given although there was a fair bit about his theories on permeable decks and vee hulls. Most of the photos had been torn out, I think a previous borrower took a shine to the famous nude crew shots.

[kharder]

My library system doesn't have any copies. I was hoping to get the hardcover to add to my nautical "library" but they are crazy expensive, guess I'll have to buy a paperback version from Wharram directly.

[kharder]

There are a couple of small details that need to be taken care of so we can get to gluing. The mast foot is already shaped so that end is done but the top end of the mast needs some attention.


Here are the two masthead sheaves nearing completion. The grooves were shaped with a rat tail file and a little patience. all told these took about 20 minutes.





A test fit with 1/4" line which is size of the future main and jib halyards.





The plans call for a space between the sheaves but didn't specify what so here is our answer: a 1/8" thick piece of douglas fir ripped on the table saw from some beam scraps. The two sides of the spacer and the grooves are coated in epoxy since they will be hard to reach. The whole unit is then glued together and ready to drop into corresponding cutouts in the mast halves.




We don't need these quite yet, but right to left shows the process or making the thumb cleats which will hold the stays at the top of the mast. The grain is oriented parallel to the outside edge for maximum strength even though the stays will be pulling toward the mast and downward. Who knows one day someone, probably me,f may try raising the mast by pulling on one and I'd like them to not break.




Which all lead up to the big event of gluing and clamping the mast halves together. I have quadrupled my army of bar clamps but still don't have as many as I would have liked for this job.




All told it came out nicely though and it's good to have the spars roughed out and ready for finishing when the rest of the boat is farther along. We're still waiting for the day when we have something that looks like a boat, hopefully that day will be here soon.

[kharder]

One thing we have learned is that gluing one floppy thing to another floppy thing means you're going to need a ton of clamps. Not wanting to spend the money on 30 or 40 spring clamps we went with the PVC clamp method.




It started with spending way too much time cutting 1" sections of 2" PVC pipe with a pull saw, then taking a short cut and using the circular saw, then realizing you have created a 10' radius of PVC chips in the yard and then finally shop-vac'ing your lawn to get it all cleaned up. But in the end we had plenty of clamps to get the hull sides ready for stitching.

Boston has finally warmed up enough that we can work outside again which was a treat after all that gluing in the basement. The stringers are held with the clamps and a few staples from the underside to keep them from sliding around. We also glued on the doubling blocks which go at the lashing points for the beams and mast stays.




Here is hull side #2 sunning and hull side #3 glued and clamped up. By this point we have given each panel a final home as to which side of which hull they will become. Only the outside face of each hull gets the supports for the mast rigging so we put the two panels with the roughest seams on the inside where they will only be seen by the fishes.




The forecast says rain tomorrow morning but sun again in the afternoon so that should be enough of a window to glue the last hull side.

[JimD]

Looks like this boat is going to have some fabulous bits and pieces.

[kharder]

We have been working on the boat since last June and today we are finally done with Sheet 1 of the plans! The hulls are now stitched together and ready for the bulkheads just in time for the warmer weather. We are pretty far along with other bits and pieces but we still haven't seen anything that looks like a boat, until now that is.

But before starting to stitch, we found mistake #3 with the bow panels. We made the top side too long which means the stem wouldn't fit. Something about the measurements on the plans didn't add up because the measurement from the edge of the ply was right, but the measurement from the bulkhead was wrong. You can see that we have to take off a small triangle from the front which was pretty easy with the pull saw, then used a chisel to bevel the edge of the butt block.



We also drilled the rudder lashing holes on the drill press before attaching the aft stems. These were a bit messy for our taste and so the next ones were done with a piece of wood clamped to the drill press table as a fence to keep the holes more neatly aligned.



And then it was time to start putting in stitches of copper wire! Here are the stitches along the bow. You can see how narrow the filler piece is now that we cut it down. The stitches in that area go through the main hull panel so we don't rip open that seam when the hulls are opened out.



We then stitched the aft stem and keel.



We couldn't help but open it up with one bulkhead and see what it will look like.



Check it out, it's a boat!




Unfortunately we will probably put the stitched hulls aside and go back to the beams and other small pieces while we wait for the fiberglass tape to be delivered and for a warm weekend day to do the epoxy work. Our plan is to do all the epoxy, fillets and fiberglass tape in one continuous process. It won't be this weekend and it won't be next weekend so perhaps the weekend after we'll have some glued up hulls.

[kharder]

Yesterday was the most gratifying build day yet, we can finally see the shape of one of the hulls! We have put so many hours into the pieces and prep work and it is finally starting to come together. We wanted to stitch the bulkheads into both hulls but ran out of both time and copper wire so this is all for now.

The shape is surprisingly sophisticated for a v-bottomed canoe. The flat edge of the hull panel transforms into a nice sheer line with a sharp entry and curved aft sections.



The last bulkhead was the most difficult to fit. There is a lot of curve in the plywood hulls and a lot of tension getting the bulkhead into place. The stitching holes are offset which pulls the bulkhead down into the hull as the stitches are tightened



Here is a view from the stern. The clamp is distorting the shape of the sheer a bit but we'll fix that when the stern stem stitches are in.



Now it finally looks like a boat!






With no real work left to do we held up one of the unfinished beams so we could stand in the right spots and imagined laying out on the deck, sails set cruising the Boston harbor islands, the Cape and beyond.

[kharder]

The next step after stitching in the bulkheads is to add diagonal stiffeners to brace the thin hull panels. The diagonals go on the two fore sections and the one aft section of hull. The middle sections get their bracing from the floor structure. Here is a diagram showing the diagonal bracing in bright green and how it ties the keel and stem structure up to the sheer.





I cut each piece to fit and then made sure I had scraps the right length to use as bracing. Everything went smoothly in the test fit so I moved on to gluing. Funny how everything seems to stop going according to plan once you slather on the epoxy.


The epoxy got rid of the stiffener to hull friction so the clamping pressure kept trying to slide the pieces up and out of the hull. Adding staples or clamps near the sheer fixed the problem. The plans call for stitching these in but we have already drilled enough holes in our hulls and the stitches wouldn't have provided enough clamping pressure anyway.


Installation started in the bow section re-using the PVC clamps ...





.. then the next section aft (using staples so no clamps) ...





... and finally the aft section.





This hull is ready for fillets! One down, one to go.

[timo4352]

Good progress.

[kharder]

Our catamaran is all stitched up. It's not as convenient to work on as a double-decker. Thant's ok though because there is no other way to fit the two hulls in the basement at the moment.





The top hull is held up temporarily with some scrap wood and clamps.





Here are some more details that are pretty obvious when your are stitching, but aren't in the plans. The plans give a measurement for how to cut the angle on the end of the sheer stringer, but it's much easier to clamp in place and cut parallel to the stem.





The other complication is the supports on the bulkheads are on the narrower side. So they need to be beveled to match the angle of the hull to sit flush.





Right now the sides are not sitting exactly right on the aft stem on both hulls. At least they are both the same. I think we can pull it into alignment using a rope tied to the front stem handle. It probably doesn't make much difference but I want to make sure that the deck will line up with the bottom of the handle,





That's all for now. I predict that there will be a lot more gluing in our future

[timo4352]

Man, that stich & glue sure goes together quick. Maybe this fall I'll get started on my catamaran build, but for now I'll enjoy watching yours.

[kharder]

I'm glad your enjoying it. Stitch and glue boats seem a bit like companies going bankrupt, things happen very slowly then all at once.

Getting the spars and beams out of the way over the winter was contrary to the sequence in the plans, but we knew we would't want to wait around once we had the hulls done. A couple of good weekends spent up to our elbows in epoxy and things will really be moving along!

[gstanfield]

Looking good! Keep up the good work

[Dan St Gean]

Nice job so far fellas. Are you going to try to assemble at the ramp or keep it afloat somewhere?

dan

[kharder]

In the short term I think we're going to either keep it on the beach or on a trailer. The plan is to bottom paint anyway because we would like to have it in the water over some longer camp-cruising adventures. A couple towns over has cheap and available mud berth moorings in a really nice harbor, but you may need to be a town resident so who knows.

Are there trailers that let you slide the hulls out to assemble on the trailer? It's too wide to trailer with the beams attached (~10' beam)?

[AnalogKid]

I used to drive past this Tiki 21 everyday on the way home from work, but it's moved now. The custom built trailer allows the hulls to be swung out to the right width to be lashed before launching. Pretty neat but probably quite pricey unless you can weld and get a good deal on hot-dip galvanizing.






Cheers,
Andy.

[Dan St Gean]

Yeah, at 11' you won't be able to tip it up like the Tornados do. Storing it mast up at a yard might work, a cheap mooring that dries out would be a nice option, or a special trailer. I hated the prep time for daysails, so I went with a narrower and less stable cat. It would be easier to right, but it would also be easie to capsize in the first place with it's H18 rig. If you are using it for daysailing, go with a mast up option. If you are only getting it wet for weekend+ long trips, you could store it however you want. You'd have to do a sliding trailer of some sort which frankly shouldn't be too bad. Lashing is time consuming though and your boat has 12 beam lashings and the deck too, so minimising time is critical. Use the trailer for distant cruises and go mast up locally any way you can manage.

Dan

[kharder]

Sounds like good advise. I can imagine tying all those lashes and particularly the trampolines will take up a good amount of sailing time. We're considering a solid deck between the main and aft beams for that very reason with the benefit of staying a bit drier but not sure how to do it while keeping the weight down.

[kharder]

Today we found ourselves with a free day to spend working on the boat and then it rained non-stop. The weather is always gorgeous when one or the other of us is busy, but we can't let that stop us getting out on the water. Since we are confined to the basement we decided to work on the beams and save the hulls for another day.


The compression support blocks were trimmed pretty close before we glued them, but needed some adjustments so that the top and bottom boards of the I-beams would sit level. We are trying to keep all of the saw dust generating activities out of the basement but it was raining so this was our compromise. The saw-rasp evened things up pretty quickly





We took advantage of a brief break in the rain to sand the epoxy coated faces of the center beam pieces. There was some concern with the metric conversions that we may have made the beams too narrow so we double checked while measuring for the top board of the main beam. It is actually an inch long which means we'll get that much more room when sailing.


In the dry test fit it looked like we could get away with four clamps and use the stiffness of the board to close all the gaps in a fair curve.





In reality it took 7 clamps, good thing we only epoxied up one at a time! This was about the time Cam said, "If we just had more space and more clamps, think about how much we could get done!"





Sighting down the beam makes sure that the it is straight and centered. Right after this photo we adjusted the closest part a bit to the right as you can see that it is a little off.





After a few hours it was time for more fillets. The middle two sections get a 1.25" radius fillet.





The outside sections step down to a 5/8" fillet which you can just see in the corner of this picture. Probably could have done the fillets once both boards are on but it seemed easier to do now while there was better access. For the next ones I'll wait till the clamps are out of the way, it's hard to keep the epoxy off of them.





One half of one beam down, can't wait for the weather to clear so we can move outdoors. That will solve the space issue, I'm not sure I'll ever have enough clamps though.