Choosing wood for strip-built canoe

[jaredbeck]

Hi y'all

I'm building Nick Schade's Nymph (see WB 199)



http://bp0.blogger.com/_jYPmLnC5fNM/R1IMmTO30RI/AAAAAAAAAAM/DGr1vHps_AU/s320/nymph.jpg



It's a strip-built canoe, with 1/8" strips, to be encapsulated with glass and epoxy. The design goal is a lightweight canoe. (My goal is a canoe that floats)

He says he prefers cedar, but uses basswood in the article, though he notes that basswood is heavier.

Can you recommend a choice of wood for the strips? (I live in central New York state) What would be your first choice? Second choice?

Thanks in advance, and sorry if this is in the FAQ already .. I didn't see it.

Edit: The darker strip in the picture is walnut.

[Jon Etheredge]

Northern White Cedar would be the lightest weight. Trees are typically small so the lumber tends to be knotty.

Western Red Cedar is commonly used. Slightly heavier than Northern White. The reddish color is preferred by some folks.

Atlantic White Cedar is similar in weight to Western Red Cedar. Usually not knotty like the Northern White Cedar.

Any of these would be fine.

[Wild Dingo]

A fair few people are starting to use Pauliwannia or Kiri for their strippers seems to work out nigh on perfect... and as close to Balsa light as a sneeze from a gnat ;)


oooh is Balsa light enough? :confused:

[Bob Perkins]

Having built a strip built canoe years ago... I'd say you can pretty much use anything you want (ok - maybe not balsa..).

Western red cedar is what I used. Certainly any light weight wood is good. But you can add accent strips of mahogany, walnut, cherry, whatever.. Since the whole thing gets glassed inside and out.. The wood will (should) never get wet.

So pick what you like.

[Canoez]

I tend to agree with Jon's notes.

You could also use Redwood if you've got a bottomless wallet. Another choice (for whiter wood) is Port Orford Cedar (a Juniper family actually, IIRC) - a bit heavier than Western Red or Eastern White.


I'd skip the Balsa idea - you want a wood that has a bit of mechanical strength to avoid crushing and delamination from the fiberglass.

We tend to stay away from hardwood accent strips and use Poplar, Spanish Cedar, Redwood and the like because when you fair and sand the hull, the softwood next to hardwood is eaten away first, leaving the hardwood proud. Not a good situation.

[Chan]

excellent point Canoez

[jaredbeck]

Wow, so many kinds of cedar.

On the hill behind the house I grew up in there are these gnarly old grey trees with purple heartwood. My dad used to call them "Aromatic Cedar". What is the correct name?

[Canoez]

Wow, so many kinds of cedar.

On the hill behind the house I grew up in there are these gnarly old grey trees with purple heartwood. My dad used to call them "Aromatic Cedar". What is the correct name?

"Aromatic Cedar" - I think that's correct. Bob Smalser had some great posts to a thread about good boatbuilding woods in terms of strength, weight and rot resistance. Was in the past month or so, I think. I'll see if I can dig it up.

I'd be a bit careful about Nick's building method. He's very experienced in strip building and makes it look easy. Thin strips (1/8" like he's using) don't give you much margin for error if you don't get the edges perfectly flush as you strip. Also, when you go to fair the hull, there isn't that much material there - DON'T sand through!

[JimD]

There's enough colour variety in wrc that you could make accents or patterns with it without resorting to mixing wood species.

[rdrishel]

Here in the deep south cypress would be the light, strong wood of choice. The heartwood from aromatic cedar is the stuff used in furniture but it is very brittle and usually not very long.
I wonder if standard "whitewood" construction lumber would work since it can be had in long clean boards.

[Canoez]

Here in the deep south cypress would be the light, strong wood of choice. I wonder if standard "whitewood" construction lumber would work since it can be had in long clean boards.
Cypress would be nice. "Whitewood" - usually poplar - would do the trick but would be a bit heavier.

If you can find long lengths of Sassafrass, it's nice, but a bit splintery. Makes a relatively light boat that looks somewhat like oak. Smells nice when you work it. Led to the name of one of the canoes build from it : The Root Beer Float.

[Jon Etheredge]

I would guess that almost any wood (including whitewood) could be used for this canoe. Schade has speced 4 oz. S-glass on the exterior and 6 oz. carbon/kevlar cloth on the interior. This is more exotic cloth than is used on your run-of-the-mill strip canoe. As Canoez says, with 1/8" strips you don't have a large margin for errors.

I wonder how much real weight savings there is by using this construction method. It seems like a schedule of 1/4" cedar strips with 4 oz. E-glass exterior and 6 oz. E-glass interior would be plenty strong, (much?) cheaper, easier to build, and would carry a negligible weight penalty. Anybody have any real data or other opinions about this?

[rdrishel]

There is a type of construction lumber that is readily avaialable here that is usually called spruce. I think is some kind of plantation grown canadian fir but it is a nice soft clean whitewood.
Sassafras would be really great but I doubt it is commercially avaialble. It takes a long time to build a boat when you start with a standing tree.

[Canoez]

There is a type of construction lumber that is readily avaialable here that is usually called spruce. I think is some kind of plantation grown canadian fir but it is a nice soft clean whitewood.
Sassafras would be really great but I doubt it is commercially avaialble. It takes a long time to build a boat when you start with a standing tree.
I would not use spruce or any other resinous wood. When the sap leaches out, you can have problems of delamination.

Sassafrass is commercially available, but not readily here up north. It's a "Southern" tree and can be found at a good wood supplier who deals with professional cabinetmakers. Sadly, it isn't usually in long lengths and a great deal of scarfing is required. It can also be a bit brittle.

[Cuyahoga Chuck]

There is more to wood choice than just appearence, cost, availability and weight.
There will be considerable amounts of back labor expended. The easier the wood is to work the less time you will spend eating dust. Western Red Cedar fits because it gives you workability along with the other desireable features. Because WRC is available in long, clear lengths it is possible to get fairly good color matches, too.
Wood that has knots can be prettied up if you know how to make scarf joints. This is also an option if you can only get the desired lumber in short lengths.
There is some discussion about using very thin strips. Stippers are, basically, fiberglass hulls with a wood core. The core, which can be made from materials besides wood, spaces the layers of glass apart and a much stiffer panel results. As the glass layers get closer together the stiffness decreases. I've never seen a Nymph so I don't know what may have been given up to achieve a very thin, lightweight hull.
I am a fancier of lightweight canoes myself but would hesitate to attempt stripping with 1/8th strips because the margin of error is very small. Sanding thru' a 1/8th piece of wood is rather easy especially when both sides of the strip have to be sanded.
In the eastern United States high quality, straight grained, basswood is very common. It's the woodcarvers delight. It works very well. Those large carosel animals are all carved from basswood. Not a particularly good boat wood but plenty good enough as long as the epoxy/glass layer is not penetrated.
Now that I've shot my mouth off I'm going to see what I can drum up concerning the Nymph. Retractions will be made if necessary.

"Y'all? In New York State? C'mon!"

[Canoez]

I would guess that almost any wood (including whitewood) could be used for this canoe. Schade has speced 4 oz. S-glass on the exterior and 6 oz. carbon/kevlar cloth on the interior. This is more exotic cloth than is used on your run-of-the-mill strip canoe. As Canoez says, with 1/8" strips you don't have a large margin for errors.

I wonder how much real weight savings there is by using this construction method. It seems like a schedule of 1/4" cedar strips with 4 oz. E-glass exterior and 6 oz. E-glass interior would be plenty strong, (much?) cheaper, easier to build, and would carry a negligible weight penalty. Anybody have any real data or other opinions about this?

On Mac MacCarthy's Wee Lassies, we use 4oz E-Glass in and out with decent results. I don't have any data on the strength comparison. Were I to do E-Glass inside and out on the Nymph, I'd probably put the 6oz on the outside and the 4oz on the inside, but that's just me.

The wood savings in going with 1/8" should be significant - for a boat this size I think that he's looking at about a 5 pound savings or so. Nick wrote in the article that he was concerned about the availability of Cedar which was why he was going with the basswood.

I wonder about the difference in strength that is a result of the thickness difference. I think about strip construction in terms of being a foam-core composite where the wood is the foam. The further apart the tensile (composite- fiberglass - carbon/kevlar) layers are the stronger I expect it to be.

Carbon/Kevlar composites aren't cheap or very available - the US government's efforts overseas lately have been soaking up great quantities of the stuff. The Carbon/Kevlar twill is stiff, strong, light and will hide any flaws on the inside - perhaps minimizing the finishing work on the interior. There's also the "Hi-tech" look factor to the stuff as well.

[jaredbeck]

I would guess that almost any wood (including whitewood) could be used for this canoe. Schade has speced 4 oz. S-glass on the exterior and 6 oz. carbon/kevlar cloth on the interior. This is more exotic cloth than is used on your run-of-the-mill strip canoe. As Canoez says, with 1/8" strips you don't have a large margin for errors.

I wonder how much real weight savings there is by using this construction method. It seems like a schedule of 1/4" cedar strips with 4 oz. E-glass exterior and 6 oz. E-glass interior would be plenty strong, (much?) cheaper, easier to build, and would carry a negligible weight penalty. Anybody have any real data or other opinions about this?

I would be perfectly happy with a heavier canoe if it made my bevels and my fairing a lot easier. I picked this canoe for it's looks, and because it is strip built. The lightweight aspect was just a bonus.

Thanks for all your comments so far, everyone.

[Canoez]

I would be perfectly happy with a heavier canoe if it made my bevels and my fairing a lot easier. I picked this canoe for it's looks, and because it is strip built. The lightweight aspect was just a bonus.

Thanks for all your comments so far, everyone.

You don't HAVE to bevel the strips. You could use 1/4" thick cove and bead strips. You'd still have to do some bevel work where the tumblehome meets the rest of the hull as he shows in the article... Don't think it would be hard to do. Weight for this boat would probably be in the 20-25# range built that way in WR Cedar.

[Cuyahoga Chuck]

Retraction#1. Carbon/Kevlar is too rich for my wallet. Should have known there would be a klinker in there somewhere.
Schade has a popular kayak building web site which I have vistited for years and I don't recall the Nymph ever being mentioned. There's not much carbon/Kevlar being used up here in the cheap seats.

[Canoez]

Retraction#1. Carbon/Kevlar is too rich for my wallet. Should have known there would be a klinker in there somewhere.
Schade has a popular kayak building web site which I have vistited for years and I don't recall the Nymph ever being mentioned. There's not much carbon/Kevlar being used up here in the cheap seats.
Nymph must be relatively new as a design. He had her at the WB show on display on stands.

Nope. Carbon/Kevlar isn't for the cheap seats. I think it certainly helps give that thin hull some strength, 'tho.

[Cuyahoga Chuck]

Just checked. Nymph is only 10' long. Carbon /Kevlar is a walloping expense for such a small boat with such limited applications.
Sorry, for the outburst of personal opinion. I'm not much of a fan of short waterline paddleboats.

[jaredbeck]

Just checked. Nymph is only 10' long. Carbon /Kevlar is a walloping expense for such a small boat with such limited applications.
Sorry, for the outburst of personal opinion. I'm not much of a fan of short waterline paddleboats.

Firstly, I am spacing the forms apart to give a 12' long boat, as the designer suggests for heavier people :)

Also, I had been wondering about the Carbon/Kevlar business. I had guessed it would be out of my price range, but I hadn't looked into it really.

[Jon Etheredge]

Well, I did some 'back of an envelope' type calculations on the weight penalty of going from 1/8" - 1/4" strips...

Schade says the Nymph weighs in at 15 pounds using basswood, walnut, carbon/kevlar, and S-glass.

To simplify things, I have assumed that the wood core weighs 28 lbs/cubic foot (this is a quoted weight for basswood at 12% moisture content).

If the wood core accounts for 60% of the total weight and keeping everything else constant, changing from 1/8" basswood to 1/4" western red cedar will make a difference of about 7.6 pounds. So the finished boat should come in a little under 24 pounds.

If the wood core only accounts for 50% of the total weight then the weight penalty drops to 4.8 pounds.

I don't know exactly what percentage of the total weight is actually due to the wood core but it probably isn't any more than 60%. The rest being taken up by the cloth, resin, stems, gunwales, thwarts, and varnish/paint.

If you went with 4 oz. E-glass on both sides then the quantity of resin required would drop too so there would be some weight savings there.

In short, my supposition that they the weight gain would be negligible is wrong (depending on how you define negligible of course ;)). But the weight gain would be still be tolerable to many builders. It seems like Canoez swag of 5 lbs. weight difference is probably pretty good.

Edited to add that these numbers are based on the short boat as described in the article.

[Brian Palmer]

I built Tom Hill's Charlotte 11 1/2 foot canoe and mine weighs ~29 lbs, just for comparison. You can also check out Mac McArthy's strip built boats (his book is Featherweight Boat Building) in the same size range for some more weight comparisons.

In my humble opinion, different woods and types of reinforcement (e.g. glass vs kevlar) will still give roughly the same weight on a boat this small because you are still using more or less the same amount of "stuff" to build it, as long as you still use soft woods for the planking and trim. The weight differences are just not that dramatic if you stick to the same material dimensions. Careful building and saturation of whatever fabric you use will probably make as much of a difference in weight as the type of fabric.

You might save a little weight with kevlar, and increase puncture resistance, but you do not want to hit rocks with this boat in the first place because of the relatively fragile core and outer glass layer.

--Brian

[Tom Robb]

As to strippers being a woodboat take on glass/foam/glass construction:
IMHO - I think that'd be true only if sufficient tensile strength were built into the glass part of the sandwich. Single layers of light glass (4 -6 oz) are, it seems to me, there to basically keep a uniform coat of epoxy on the hull and to give at least the illusion of some abrasion resistance.
The wood really does provide a significant part of the stiffness of the hull.
A trained NA may have a differing opinion, of course.

[Canoez]

Tom,

When you get down to 1/4" thick, the glass/epoxy matrix is the tensile strength, not the wood. Neither the epoxy or the glass, on their own gives strength, per se. If you take the wood canoe off the forms before glassing or epoxy sealing the outside, the thing holds its shape, but is pretty much a wet noodle. The wood only adds to the stiffness (well, strength) once you get the 'glass on and it becomes part of the "system".

Brian,

The carbon/kevlar is on the inside, so it does little to increase puncture resistance. It's just fiberglass and epoxy on the outside.

I agree that for the most part, good use of epoxy lessens the weight of the boat significantly and has a large bearing on the total weight of the boat. Having build Wee Lassies from WR cedar, Redwood, Sassafrass and Eastern White, I can say that there is a total difference between them (hull weight w/o trim) of about 2-3 pounds based on wood type.

In my experience, the biggest weight difference in these small boats is in what you put on them for trim (Walnut or Doug Fir?) and how big the scantlings are. (Did ya load the thing up with husky cherry gunnels and decks? or build a more utilitarian boat with spruce or another softwood trim that will show the dings and dents a bit.)

[Todd Bradshaw]

"The wood really does provide a significant part of the stiffness of the hull."

Considering that you can lean on a stripper hull before it's glassed and split it wide open, I would tend to disagree with that statement. As to whether or not it's a wooden boat, we've been locked in that old debate for decades and I think most people have finally decided that it's a stupid argument that does little more than waste time. You should have been around back in the 1970's when all of us "stripper-building hippies" were the ugly step children of the wooden boat community. WoodenBoat used to get nasty letters to the editor for running articles about strippers. I even answered one such complaint once and made the next issue.

Spruce does not leech sap out causing delamination or any other problems (at least for the 35 years or so that I've had spruce strippers around to watch for it). Back when we could get it cheap, sitka spruce was by far my favorite wood for strippers. For a couple of extra pounds per boat, it gave a tougher core. I also liked the fact that it was a bit firmer than cedar when it comes time to bevel a strip with a plane and personally, I the looks of it. If I could get decent lengths of big-box SPF with the grain pointing the right direction, I wouldn't hesitate to use it. You can butt-joint short strips and don't need to scarph them. I have built boats with wide, but-jointed feature strips made up of chunks as short a 12" or so and built boats where all the strips running the full length of the hull were butt-jointed from shorter chunks.

Spruce boats (with redwood stripes)

http://webpages.charter.net/tbradshaw/Sail%20photos/18'%20Micmac.jpg
http://webpages.charter.net/tbradshaw/Sail%20photos/nanaimo.jpg

Be very careful building with lighter fiberglass on the inside than on the outside as it often weakens the hull significantly. The first impression that you can just lighten the inside layers to save weight without paying a penalty is dead wrong. These are the layers of the layup which are in tension when you flex the hull or run over something. They will get far more stress during these situations than the outside layers will and skimping on inside laminations is one of the most common beginner's mistakes. It leads directly to a lot of "My boat split open on the inside, what do I do now?" posts on stripper forums. This is why some folks are using Kevlar and carbon on the insides when they're trying to build ultra-light constructions - it gives much higher strength and stiffness than a fiberglass layer of the same weight would. Be that as it may,you still ought to be able to get a 10'-12' boat built with 3/16" or 1/4" strips and 6 oz. plain-weave E glass down into the very reasonable weight range with excellent all-round durability if you watch the weight on your trim-out.

[Canoez]

Another thought here on the glass weights.

I would hesitate to build anything longer than 11' with 4oz cloth unless I was going for ultra-light at the sacrifice of strength. (racing, particularly) I would also look at the hull form and see how big the "flats" on the hull are even if it was shorter than 11'. The curves of the hull help to give strength (Think about arches in architectural use) Flats don't seem to take the abuse as well as the curves do.

Without taking a look at the hull design for Nymph in closer detail, I'd stick with the recommended cloth weights/types. The blend of carbon/kevlar gives good strength from the carbon while getting rid of carbon's tendancy to be brittle with the Kevlar's flexibility and high tensile strength.

[Canoez]

Spruce does not leech sap out causing delamination or any other problems (at least for the 35 years or so that I've had spruce strippers around to watch for it). Back when we could get it cheap, sitka spruce was by far my favorite wood for strippers.

I had a student build a feature strip with what he claimed was spruce from framing lumber. He must have had a pitch pocket that was buried because something (Pitch?) bled out when the boat had been glassed and put into the sun. Looked like a little golden blister under the glass. Certainly wasn't glue or air.

Perhaps he was unclear on the stock that he had...:confused:

Question: You've had no rot/discoloration problems with the spruce as well?

[Todd Bradshaw]

I think that if a strip had big knots or obvious pitch pockets in it, I'd cut them out and use it for short chunks, rather than take chances. You should have seen the spruce we used to get though. I don't ever remember a knot bigger than maybe 1/8". We would order a stack of a dozen or so 20' 1x12 sitka spruce planks from Fred Tebb & Sons at something like $23 each and it would cost about $40-$50 to get them shipped to the midwest. We would then usually get about 28-30 3/16" strips out of each one, which means that about half of the board went out the door as sawdust (probably a crime these days and certainly economic suicide, but it was a different story back then). Need nice stiff, light, plank seats for five or six paddlers? Heck, just saw a clear 20 foot sitka spruce board into short chunks! Ahhhhh the good old days.....

http://webpages.charter.net/tbradshaw/Sail%20photos/rbig1%20copy.jpg

This hull is redwood, by the way, and every full length strip in the entire boat was butt-joint-spliced at least once (22' boat built from boards 16' and under).

As for rot, I've never seen any. If you've got rot inside a stripper hull you have a far more serious problem than what type of wood you selected. It basically means that your construction is faulty and the increased rot resistance of certain species of wood ain't gonn'a save you. The most likely scenario is delamination and core splits long before the rot ever deteriorates the wood enough to make a difference.

[P.I. Stazzer-Newt]

....

I'd skip the Balsa idea - you want a wood that has a bit of mechanical strength to avoid crushing and delamination from the fiberglass.
...


http://www.storerboatplans.com/Balsacanoe/Balsacanoe.html

Boatmik's experimental boat...

[davidrparker]

I recently bought some Radiata pine from my local building supply (not a big box store), it was 16' long, 1x3 (nominal), absolutely clear, light and .23 a linear foot. Might be a good choice.

[JimConlin]

For a boat to be built by mere mortals, 1/4" strips is challenge enough. My preference is for Atlantic white, northern white or western red cedars first, but white pine is OK, too. It's not as decay resistant and a touch heavier, but less costly and very nice to work.

[Canoez]

http://www.storerboatplans.com/Balsacanoe/Balsacanoe.html

Boatmik's experimental boat...

I'd seen Mik's article on this before. Even he comments on how fragile it is during construction and that even mounting the gunnels caused some delamination. Sounds like it worked very well overall 'tho. Don't know where I'd come up with that much balsa in big enough pieces.

I do tend to agree with Jim's comment that 1/4" strips are enough of a challenge for a first time builder - and Jim's not your average first time builder...

[Remax]

Lots of good advice from the above posts.

Here is what I wish I would have been told before I built my first stripper....


1. Don't be too concerned about the weight of the wood, in the end the amount of epoxy you put on, get faired and end up with to make a nice boat will be far more important in the finished weight.
I'd never make a canoe from oak or ironwood but the wieght difference in the various lighter woods will not be significant in the final product weight.

2. Start with 1/4" strips and pay a lot of attention to the layup and glue globs. If you want a great looking boat you WILL be doing a lot of sanding to take out lumps and other imperfections. 1/4" to begin with gives you the thickness you will need to compensate for your inexperience on a first time build.

3. The wood working part will be the easiest part if you have done any wood work before. The cloth/epoxy is where you can waste a bunch of money, ruin the looks of the canoe and end up spending a lot of time making a canoe weigh too much and look like hell. If you have not done it before try to find someone who has done it successfully to help you.
I've seen a lot of time consuming nice woodwork ruined beyond repair with a poor epoxy job.
4. This is purely subjective but.... in my opinion [and I think the vast majority of people] the most attractive strippers are mostly one color with one or at the most two accent stripes,a few well placed brass fittings and nicely woven cane or cordage seats.
Alternating circus stripes, eagle inlays, chevrons, garish colors, aluminum lawn chair seats just don't GO on a canoe. Bass boat maybe, canoe, no.
I've been to wooden boat shows where guys were very proud of and have spent a ton of time in overly ornate simple boats. Guilding the lilly times ten. Wasted time in my mind.
A simply elegant canoe gets most of its elegance from the SIMPLY part of it. Fine joints, careful color selection and symmetry of strips, attention to detail and careful camouflaging and repair of the inevitable mistakes.

Select a wood that first, looks good, and second is not overly heavy.
Learn or have help with the epoxy, pay attention and spend time on the details of seats and fittings.
You will end up with a great boat and you will be proud to say when people ask, "Yes I did make it, thanks for the compliment."

Good luck, pm me with questions if you wish.

[Todd Bradshaw]

Remimds me of the first stripper I ever saw. It was a Gene Jensen USCA racing boat at the put-in for the Des Plaines Marathon. It was gloss-varnished cedar and absolutely gorgeous, but when they turned it over, it had seats that were aluminum tube frames with green and yellow woven lawn chair fabric and the thwarts were the Sawyer-style aluminum tubes with their ends squashed flat. I remember being horrified at the contrast between the hull and trim-out. I later learned that these were 18 &1/2 footers that weighed in the thirty-something pound range and all business, thus the ultralight trim. Strip construction was used because at the time (before Kevlar, carbon, foam-cores, etc.) it would yield the stiffest hull and lightest boat. They didn't care what it looked like.

[Bob Smalser]

Wow, so many kinds of cedar.

On the hill behind the house I grew up in there are these gnarly old grey trees with purple heartwood. My dad used to call them "Aromatic Cedar". What is the correct name?

Eastern Red. Very heavy for your purpose. Also usually found flatsawn and knotty, and it's the only cedar of all of them that I've seen bleed pitch, which will interfere with gluing.

I'm not a canoe builder, but 7 or 8 pounds in a small canoe is significant, even more so because generally the less experienced the builder is, the heavier the boat tends to be. Trust the designer.

Cedars:


Our three "lightweight" cedars are predominantly used as planking woods in thicknesses varying from 3/8" to 1 1/4" on boats up to around 35'. They are around 25% lighter, correspondingly weaker, and proportionally more stable than our four "heavy" cedars, which are generally used to plank larger boats and also sometimes for framing.

The heavy cedars are Alaska Yellow, Port Orford and Eastern Red Cedar. These are closer to Doug Fir in weight, hardness and strength than they are to the light cedars. Baldcypress has similar properties and can also be included in this group, as most of the trees we call "cedars" are really in the cypress family. Eastern Red is the heaviest of the group and not normally used for boatbuilding.

The light cedars are Northern White (Arborvitae), Atlantic White (Juniper) and Western Red. Of the three, NW is lightest by a slight degree and bends the best. The trees are generally quite small however, with usually only knotty flatsawn stock available. Western Red comes from the largest tree, making clear, stable vertical grain stock easily available, but is a significantly stiffer wood than the other two. All have rot resistant heartwood, all are easy and pleasant to work, all take glue exceptionally well, and all are among the most seasonally stable of woods. Qsawn light cedar panels through widths of around three feet can be successfully epoxied and glassed just like plywood. They are also relatively soft, but boats protected by nothing but paint hold up very well in hard use.

[Remax]

By my " back of the envelope" calculation you will have quite a bit less than 1/2 cubic foot of strip wood in that finished canoe. Considering starting with 1/4" strips and figuring your sanding losses. Possibly as little as 1/4 cu.ft. Perhaps about 1/3 of the total finished weight will be the strips. About 5 to 8 pounds total strip weight. The difference in different cedars or other relatively lightweight woods will be a few pounds at most. Not really an issue especially since you said, "I would be perfectly happy with a heavier canoe if it made my bevels and my fairing a lot easier."
Be aware that lighter cloth can be pretty tricky to work with when wetted out. If you can find a helper thats done this before you will save yourself a lot of grief. Or perhaps volunteer to be an experienced builders helper on his boat. If you do a little net search or ask around at your epoxy suppliers I bet you will find a group of stripper enthusiasts in your area, these guys are generally very willing to help a novice get started.

Good luck, send pictures as you build!

[Canoez]

Another huge consideration here is actually the blades you will use to get your strips out. IF you do plan on making 1/8' strips (or 3/16" or 1/4") the waste from the blade kerf is significant.

I don't recommend products by brand, but here, I will. I've had good luck with the Freud Diablo Thin Kerf Rip blades (.093" thick) We've also been experimenting with using Freud's Diablo circular saw blades in a table saw. They're Teflon coated carbide tipped blades and are .062" thick. Most (if not all) of these blades have expansion slots and laser cut dampening cuts to get rid of excess vibration during use. They work very, very well for ripping cedar on the table saw - hard to beat for about $12 at my local lumberyard. I recommend using one of their Ø4" blade stiffeners with it to keep the wobble out.

Our next go-around will be a gang saw assembly with three of these thin-kerf circular saw blades, but that's a bit over the top for the home builder.

Bob's wood knowledge puts us all to shame again! :D Thanks!

[Canoez]

By my " back of the envelope" calculation you will have quite a bit less than 1/2 cubic foot of strip wood in that finished canoe. Considering starting with 1/4" strips and figuring your sanding losses. Possibly as little as 1/4 cu.ft. Perhaps about 1/3 of the total finished weight will be the strips. About 5 to 8 pounds total strip weight. The difference in different cedars or other relatively lightweight woods will be a few pounds at most. Not really an issue especially since you said, "I would be perfectly happy with a heavier canoe if it made my bevels and my fairing a lot easier."
Be aware that lighter cloth can be pretty tricky to work with when wetted out. If you can find a helper thats done this before you will save yourself a lot of grief. Or perhaps volunteer to be an experienced builders helper on his boat. If you do a little net search or ask around at your epoxy suppliers I bet you will find a group of stripper enthusiasts in your area, these guys are generally very willing to help a novice get started.

Good luck, send pictures as you build!

Let's see here. A 12' long canoe usually takes 13' strips. Assuming that we were going with 1/4" x 3/4" cove and beaded strips, and that it usually takes about 50 strips for a boat this size, we're talking about roughly .7 cubic feet of, let's say, dry Western Red Cedar at 21 lb/cubic foot density. That's 14.8 pounds.

If you were to go with 1/8" strips, (no cove and bead) you'd be looking at .42 cubic feet for about 8.9 pounds - almost 6 pounds less. You'll probably shave and sand off somewhere around 1/2 to 3/4 of a pound off this boat from fairing and sanding.

Thinner strips are significant weight saving, but as I think nearly everyone has noted - 1/8" strips are difficult to deal with in terms of fairing.

Personally, I don't see a big difference between working with 4 oz versus 6 oz cloth. They all take practice.

[John Turpin]

If you can find long lengths of Sassafrass, it's nice, but a bit splintery. Makes a relatively light boat that looks somewhat like oak. Smells nice when you work it.

I'd like to hear more about Sassafrass. That's actually lumber that I can get somewhat easily (compared to Northern species). Is this really a viable wood for strip planking? I know that some cabinet guys use it. I searched briefly and only found this:


The dried and ground leaves are used to make filé powder, a spice used in the making of some types of gumbo.

It is also used in the manufacture of the drug ecstasy, and as such, its transport is monitored internationally.

The roots of Sassafras was used in the flavoring of root beer until being banned in 1960.

That's interesting, but could someone use this unusual wood in boat building?

[Canoez]

I'd like to hear more about Sassafrass. That's actually lumber that I can get somewhat easily (compared to Northern species). Is this really a viable wood for strip planking? That's interesting, but could someone use this unusual wood in boat building?


Yep. You can.

It takes a bit more bending and twisting to get it into form as it is a bit stiffer stuff than cedar so I'd go with staples as opposed to staple-less construction - particularly on a first boat.

One of my students was reading Mac MacCarthy's book Featherweight Boatbuilding and Mac commented in there that if he could ever get his hands on enough Sasafrass, he'd build a canoe from it. Soooo... He went on a hunting trip up to a local lumber supplier and found some, but only in short lengths. Every strip on his 11' long canoe was scarfed, but it was Sassafrass. Smelled of root beer when you cut or sanded the wood. Sadly, he had trouble getting the desired grain orientation for the strips and we had issues when fairing of the plane catching the grain and tearing (The plane iron WAS sharp like a razor and well-set, too). Other than the issues above, no problems with building with it.

It's about 25% heavier than Western Red Cedar.

Looks like this:
http://www.woodfinder.com/woods/scans/sassafras.jpg

[Bob Smalser]

I'd like to hear more about Sassafrass.

Heavy for your purpose, but pleasant and easy to work.

Slightly lighter and slightly weaker than Doug Fir, but much more flexible. That makes it 50% heavier than Western Red Cedar (SG.48 to SG .32) and bending about the same.

[Canoez]

Bob,

Density of Western Red Cedar - 21 lb/ft3
Density of Sassafras - 28 lb/ft3

No?
:confused:

[Remax]

Canoez, I made a generous allowance for waste, cutoffs and sanding loss.
On my last solo I weighed the hull before and after glassing. I was amazed at the wood waste weight loss and the wieght gain of glass and epoxy. Way different ratio than I have always presumed.

If this builder has the inclination I hope he weighs his like this.
I'd like to see the figures just for fun.
The next one I build may be something similar. But I need to get rid of a few boats first.:)

I may be wrong.... but I think I'm close.

[Bob Smalser]

Bob,

Density of Western Red Cedar - 21 lb/ft3
Density of Sassafras - 28 lb/ft3


Chicken or egg? There are minor differences in data just like there is in nature, and a half dozen ways to express the data. ;)

Water is 62.4lbs/ft3. WRC @ SG .32 is .32X62.4 or 20lbs/ft3 Sass @ SG.46 is 28.7lbs. Delta is 8.7lbs. 8.7lbs is 44% of 20lbs/ft3.....or....Sass is 44% heavier than WRC.

[Canoez]

Chicken or egg? There are minor differences in data just like there is in nature, and a half dozen ways to express the data. ;)

Water is 62.4lbs/ft3. WRC @ SG .32 is .32X62.4 or 20lbs/ft3 Sass @ SG.46 is 28.7lbs. Delta is 8.7lbs. 8.7lbs is 44% of 20lbs/ft3.....or....Sass is 44% heavier than WRC.

Thx. It's just the engineer in me...:D

[Jon Etheredge]

By my " back of the envelope" calculation you will have quite a bit less than 1/2 cubic foot of strip wood in that finished canoe.


Oops, I just noticed that I have a typo in my earlier post. Basswood is said to weigh 26 lbs/cubic foot. I used this number in my calculations but mistyped it as 28 lbs/cubic foot in my previous post.

Anyway, I did my weight penalty calculation as follows:

Pick a number for what percentage of the total weight is taken up by the strips. As a start, we can say 60%. Schade said the finished weight of his 10' boat was 15 pounds. Then the weight of the strips is

15 lbs * .6 = 9 lbs

So the volume of wood in the strips is

9 lbs / 26 lbs per cubic ft = 0.346 cubic ft

If we double the strip thickness (1/8" -> 1/4") then the volume of wood in the strips doubles. If we use western red cedar at 24 lbs per cubic ft then the weight of strips will be

(0.346 cubic ft * 2) * 24 lbs per cubic ft = 16.6 lbs

So the weight penalty is 7.6 pounds.

I got these weights for Basswood and Western Red Cedar off of the web. Now I see others are using figures of 20-21 lbs per cubic ft for WRC.

That makes the numbers look a lot better :)

Using 21 lbs/ft3 I get a weight difference of only 5.5 lbs with the 60% of total finished weight attributed to the wood core and only 3.1 lbs difference if the wood core is only 50% of the finished weight.

Maybe the assumption about the percentage of total weight that is attributed to the strips is way off here. I really don't know. I suspect it is between 50-60% for a builder that is able to squeegee off ALL excess epoxy when wetting out the cloth.

[Cuyahoga Chuck]

If you use 1/8th strips there is not much that can be shaved off while ¼ " strips will tolerate a lot of wood removal by comparison. How you can calculate the weight difference looks like a head scratcher to me.
I suspect a secondary reason Schade went for the carbon /Kevlar inner lamination is to avoid having to work the insides of those very thin strips.
This looks like a sound engineering decision to me but, costly.

[Canoez]

If you use 1/8th strips there is not much that can be shaved off while ¼ " strips will tolerate a lot of wood removal by comparison. How you can calculate the weight difference looks like a head scratcher to me.
I suspect a secondary reason Schade went for the carbon /Kevlar inner lamination is to avoid having to work the insides of those very thin strips.
This looks like a sound engineering decision to me but, costly.

Chuck,

The thinner strips twist easier and provide a more "fair" surface, so less material needs to be removed. It's hard to get the faces of the strips to stay coincident, however. I do a fair amount of stripping and found it difficult. My earlier weight estimates were based on material that goes into a similar sized boat and what comes off during fairing.

I had a strongback and forms set up in the basement (different canoe design) and after I read the article, I went downstairs and ripped some relatively short scrap poplar into 1/8" x 3/4" x 8' long strips* and tried it on a section of the hull. It worked OK, but the biggest problem that I had was getting the edges of the strips lined up between the forms. I used blue painter's tape running along the strips both inside and out to try to keep them aligned. Close to the ends, where there was lots of twist, I used spring-jaw clamps with swivel pads (in addition to tape) - sometimes 2 or three between each form - to keep the faces of the strips flush. I'd like to cut some patterns and try Nick's boat in a 12' length or so. Other priorities first, tho. :rolleyes:

*The ratio of strip to dust generated isn't great... Lots of waste!

[Horace]

May I suggest yellow (or tulip) poplar (Liriodendron tulipifera)? The wood is relatively soft, light, even-textured, non-resinous, knot-free and straight-grained in great lengths, easily worked and finished, variably colored (light tan, yellow, green, brown) and readily available in the eastern US. It has moderate strength and low decay resistance, and is generally used for cabinetry and furniture. I have seen it used for glassed strip-planked kayaks locally (with full length strips).

[jaredbeck]

Hello again. I've been reading your comments today during work, but didn't have time to respond until now. So, there's a lot to respond to .. sorry if this reply is too long.

Here's what the forms look like. The tumblehome edge you see here will be about halfway between the gunwale and the DWL.


http://bp1.blogger.com/_jYPmLnC5fNM/R1xvZYuCIBI/AAAAAAAAACA/ntXLVO_VMMo/s1600/forms_mounted.jpghttp://bp1.blogger.com/_jYPmLnC5fNM/R1xvZYuCIBI/AAAAAAAAACA/ntXLVO_VMMo/s320/forms_mounted.jpg



For a boat to be built by mere mortals, 1/4" strips is challenge enough. -JimSo, I think I'll go with 1/4" strips, and 6oz E-glass. This comment was encouraging:


you still ought to be able to get a 10'-12' boat built with 3/16" or 1/4" strips and 6 oz. plain-weave E glass down into the very reasonable weight range with excellent all-round durability if you watch the weight on your trim-out. - ToddAs for which wood I will buy .. this thread has given me a lot to think about. How about the following priorities?
Do not use the following:
very heavy or weak wood
highly resinous wood
Preferable qualities
Clear (or close to it)
Long and straight
Workable
Strength to weight ratio
My needs
Not too expensive
Available in central New York state So, after Christ Mass I will be calling the local lumber yards.


I've had good luck with the Freud Diablo Thin Kerf Rip blades (.093" thick) I recommend using one of their Ø4" blade stiffeners with it to keep the wobble out. -CanoezThanks for the recommendation. How does a "blade stiffener" work?

Thanks for your comments everyone. Much appreciated.

[Bob Smalser]

How does a "blade stiffener" work?

I like the Diablo blades too, they are are occasionally found inexpensively in lots on eBay and are like adding 3hp to your saw.

A blade stiffener is a tempered steel disk that mounts like a washer over a thin-kerf blade to prevent it from deflecting and cutting inaccurately. You may not need one on thin cedar. Just keep your rate of cut slow without crowding, and check the first few and samples thereafter for true.

[Canoez]

What Bob notes about the blade stiffener. I don't find that I need it for the .093" blade designed for the table saw, only if I'm trying to use the 7 -1/4" dia. .062" thick blades designed for the circular saw - they're mighty thin and if you push them hard at all, they become floppy in a hurry.

Oh - pay close attention to the blade's rotation if using the blade for the circular saw - IIRC, it's printed on the opposite side from a table saw blade and not too difficult to install the blade backwards if you're not paying close attention.

[George Roberts]

"Schade ... sound engineering decision ..."

One should never put those words together.

The hodgepodge of materials he specs is expensive rubbish. And his instructions would make any engineer wince.

As I have said before the most suitable blend of materials for wood strip boats is 1/3 wood, 1/3 glass, 1/3 resin. About 5-8oz/sqft total weight depending on one's skill. Even the 5oz/sqft total weight is better for a kayak of that size than what Schade specs.

As for assembly of thin strips. It is possible to do perfect assembly of even 1/16" strips using only a bit of tape and some small spring clamps. Not much skill is needed. Just a few hints and a bit of care.

Time to go now.

[davidrparker]

................and what would those few hints be if you please? This is getting interesting.

[Canoez]

As for assembly of thin strips. It is possible to do perfect assembly of even 1/16" strips using only a bit of tape and some small spring clamps. Not much skill is needed. Just a few hints and a bit of care.
Time to go now.

:mad: 1/16"? 'Tisn't strip construction - that's VENEER!

[Remax]

I'd like to know the particulars about building a boat with 1/16 " strips George.
It sounds somewhat impossible but I'm always willing to learn and if you really have a great new design I would be willing to pay for instruction.
I'm sure other ones here would also be interested.
Care to share?

[mewolf1]

Feels funny posting my first post on this forum with advise, however, I've built a bunch of strippers and taught alot of folks "how-to".
Yes, use 1/4" strips, lots of wood comes off in the faring process and a 16-17' canoe should come in around 55-60 lbs.
Use Western Red Cedar. It has one of the best strength to weight ratios for the construction and type of boat you're building(actually a composit boat with a wood core;)).
You also don't need to buy wood as long as your boat; EVERY STRIP IS A BUTT JOINT, they might be edge to edge but it's still a butt. Just alternate your butt ends so they are not stacked. If there is a knot, cut it out as has been said, the sap will cause a delam. Small pin knots are of little concern.

Almost any wood would make a stripper, but it's tuff to beat the warmth of cedar. JMO

Kent

[Pierce Nichols]

"Schade ... sound engineering decision ..."

One should never put those words together.

The hodgepodge of materials he specs is expensive rubbish. And his instructions would make any engineer wince.

What are your favorite references for strip-building?

[Canoez]

Feels funny posting my first post on this forum with advise, however, I've built a bunch of strippers and taught alot of folks "how-to".
Yes, use 1/4" strips, lots of wood comes off in the faring process and a 16-17' canoe should come in around 55-60 lbs.
Use Western Red Cedar. It has one of the best strength to weight ratios for the construction and type of boat you're building(actually a composit boat with a wood core;)).
You also don't need to buy wood as long as your boat; EVERY STRIP IS A BUTT JOINT, they might be edge to edge but it's still a butt. Just alternate your butt ends so they are not stacked. If there is a knot, cut it out as has been said, the sap will cause a delam. Small pin knots are of little concern.

Almost any wood would make a stripper, but it's tuff to beat the warmth of cedar. JMO

Kent
I'd agree with all of that with the exception of the butt joints. For those I'd say "sometimes". It really depends on the length of the boat and in particular, the shape of the hull. Also, for a beginner, not having to join strips makes for a quicker more trouble-free build. With experience (or if building a 17-18') joints are either no problem or a necessity.

On longer boats where the change in curvature is minimal, butt joints can work just fine. On shorter ones or asymmetrical hulls where the change in curvature is rapid, you can wind up with a "knuckle" in the strip. This gets faired off the outside, but isn't as easy to get rid of the hollow left on the inside. Butt joints are also fairly weak and if you get an impact, the small area of end grain gives up the ghost fairly easily. (Fiberglass and epoxy tend to minimize this...) I do, however, personally prefer a scarf joint for my strips for these reasons.

That being said, I have used butt joints on some boats with decent results. I usually use them when making a feature strip where continuous lengths of strip run past my butt joints. This seems to work well because most of my feature strips are well above the waterline and risk of impact and the curvature there is fairly minimal on the boats I've worked on.

And no, there's nothing like the warm glow of a wooden boat!:D

[mewolf1]

I'd agree with all of that with the exception of the butt joints. For those I'd say "sometimes". It really depends on the length of the boat and in particular, the shape of the hull. Also, for a beginner, not having to join strips makes for a quicker more trouble-free build. With experience (or if building a 17-18') joints are either no problem or a necessity.

On longer boats where the change in curvature is minimal, butt joints can work just fine. On shorter ones or asymmetrical hulls where the change in curvature is rapid, you can wind up with a "knuckle" in the strip. This gets faired off the outside, but isn't as easy to get rid of the hollow left on the inside. Butt joints are also fairly weak and if you get an impact, the small area of end grain gives up the ghost fairly easily. (Fiberglass and epoxy tend to minimize this...) I do, however, personally prefer a scarf joint for my strips for these reasons.

That being said, I have used butt joints on some boats with decent results. I usually use them when making a feature strip where continuous lengths of strip run past my butt joints. This seems to work well because most of my feature strips are well above the waterline and risk of impact and the curvature there is fairly minimal on the boats I've worked on.

And no, there's nothing like the warm glow of a wooden boat!:D

I've never experienced any trouble with butts and a smaller boatwould be narrower, thus not have much more torque on the wood than a bigger one; however, you're right about scarfs and are easy to do by laying the new strip over the last and cutting them at the same time, thus making a perfect fit every time.:)

[George Roberts]

davidrparker ---

In an attempt to discourage building boats that require advanced skills or oversight to do correctly, I don't give out construction hints.

---

Pierce Nichols ---

I have yet to find a reference that is worthwhile. David Gerr's book gives 2 different sets of scantlings for wood strip construction. Hard to tell which is correct. Tom McNaughton's books seem to do the same. In any case both books are for much larger boats and are not suitable for small boats.

The DoD handbook is nice but it tends to move about on the internet (and one needs an advanced degree to understand it). Several universities have nice presentations on the internet from time to time. They also tend to move about as the authors change positions.

[Canoez]

:rolleyes::rolleyes::rolleyes:

[Pierce Nichols]

I have yet to find a reference that is worthwhile. David Gerr's book gives 2 different sets of scantlings for wood strip construction. Hard to tell which is correct. Tom McNaughton's books seem to do the same. In any case both books are for much larger boats and are not suitable for small boats.

I have Gerr's book. It seems from my reading of it that both can work under the right circumstances. There seems to be no clear way to select between the two sets of rules without doing a more complete analysis... and if you have to go there, scantling rules are a good deal less useful. It has motivated me to look for a copy of the Lindsay Lord book mentioned in the text (Naval Architecture of Planing Hulls). Maybe if I can find a copy that's not $100+...

I also have a copy of Schade's sea kayak book. While I find it way too 'pop' in many places for my taste, and therefore somewhat sloppy on some points, I didn't get as bad an impression as you did. I'm curious what you see as its major defects.


The DoD handbook is nice but it tends to move about on the internet (and one needs an advanced degree to understand it).

Well, I've got a BSME, so I'm probably a bit ahead of the average bear when it comes to understanding that sort of thing. :) Do you know the title or DoD number for it, so I can rustle up a copy?


Several universities have nice presentations on the internet from time to time. They also tend to move about as the authors change positions.

Can you give me some authors and/or titles so I can go find them?

[openboater]

I used to race against a guy named John Moreno (sp) from the Potsdam area , Last time I saw him he had a whitewater c-1 ripped from 2x4 spruce he built. Knots and all, BIG knots and all. Darn ugly boat, he finished top 3 that day on the Salmon as I recall. I'm sure it was polyester resin as it was 1977 or 78.

I've seen hundreds of strippers, ( and built a couple) that's the only boat that is still etched in my mine 30 years later.

[Battenkiller]

There will be considerable amounts of back labor expended. The easier the wood is to work the less time you will spend eating dust.

Wood that has knots can be prettied up if you know how to make scarf joints.

The core, which can be made from materials besides wood, spaces the layers of glass apart and a much stiffer panel results. As the glass layers get closer together the stiffness decreases. I've never seen a Nymph so I don't know what may have been given up to achieve a very thin, lightweight hull.

I am a fancier of lightweight canoes myself but would hesitate to attempt stripping with 1/8th strips because the margin of error is very small. Sanding thru' a 1/8th piece of wood is rather easy especially when both sides of the strip have to be sanded.



Haven't made too many posts here, so "Hi y'all" (sorry, couldn't resist).

Wish I found this thread when it was active. My wife wants me to build Nymph for her this winter. She is supposed to be helping me but so far we haven't even got the station molds drawn.

We saw Nymph at the Wooden Boat Show this year. I really like the look of the Carbon/Kevlar inside, which I never would have predicted given my love of wood. I've always found the inside of of lot of strippers to be busy looking around the "football" at the bottom. Schade's choice of fabric gives it a cool "tweed" kind of look that I found surprisingly attractive:

http://img.photobucket.com/albums/v306/drfera/Web%20Linked%20Images/Nymph-1.jpg

My main worry is that the boat is really on the small side. My wife has wanted a small double-bladed canoe for a while and she has tried a number of composite canoes by Hornbeck Boats and Placid Boatworks in the Adirondacks. She really fell in love with the carbon fiber Hornbeck "Black Jack" at 10 1/2" (11#) but that is a much beamier boat than Nymph. I'm afraid we will build it and it will feel too tippy to her or sit too low in the water (she's 140#). So I might go to a 12" station spacing (too bad, because a 10' boat fits into the work area betterhttp://www.woodenboatvb.com/vbulletin/upload/images/icons/icon6.gif).

This will be my second boat, the first one (Scherzo) was done in a class taught by Geoffrey Burke in New Hampshire. It is a traditional cedar lapstrake boat that is sitting in my basement awaiting the finishing touches. I remember how much harder cutting those 4" scarfs were for the cherry sheer strake than the rest of the scarfs in Northern white cedar. Northern white is like cutting butter. I think I'll stick to that wood for any strippers I build. It is cheaper and lighter and more available to me. Just gotta do lots and lots of scarfs.

The original Nymph struck me as a surprisingly stiff-sided canoe given its thin planking, a lot stiffer than my Bell canoe in straight Kevlar. I am a bit apprehensive about fairing the 1/8" planking (even though Nick told me there would be no problem if I was careful aligning the strips) so I may go to 5/32" or even 3/16". The nice thing about not using bead and cove edges is that I can make the planking any thickness I want. With the Northern white I don't think I'll notice a big weight difference, my novice epoxy technique will probably add the greatest amount of extra weight.

[Canoez]

Haven't made too many posts here, so "Hi y'all" (sorry, couldn't resist).

Wish I found this thread when it was active. My wife wants me to build Nymph for her this winter. She is supposed to be helping me but so far we haven't even got the station molds drawn.

We saw Nymph at the Wooden Boat Show this year. I really like the look of the Carbon/Kevlar inside, which I never would have predicted given my love of wood. I've always found the inside of of lot of strippers to be busy looking around the "football" at the bottom. Schade's choice of fabric gives it a cool "tweed" kind of look that I found surprisingly attractive:

http://img.photobucket.com/albums/v306/drfera/Web%20Linked%20Images/Nymph-1.jpg

My main worry is that the boat is really on the small side. My wife has wanted a small double-bladed canoe for a while and she has tried a number of composite canoes by Hornbeck Boats and Placid Boatworks in the Adirondacks. She really fell in love with the carbon fiber Hornbeck "Black Jack" at 10 1/2" (11#) but that is a much beamier boat than Nymph. I'm afraid we will build it and it will feel too tippy to her or sit too low in the water (she's 140#). So I might go to a 12" station spacing (too bad, because a 10' boat fits into the work area betterhttp://www.woodenboatvb.com/vbulletin/upload/images/icons/icon6.gif).

This will be my second boat, the first one (Scherzo) was done in a class taught by Geoffrey Burke in New Hampshire. It is a traditional cedar lapstrake boat that is sitting in my basement awaiting the finishing touches. I remember how much harder cutting those 4" scarfs were for the cherry sheer strake than the rest of the scarfs in Northern white cedar. Northern white is like cutting butter. I think I'll stick to that wood for any strippers I build. It is cheaper and lighter and more available to me. Just gotta do lots and lots of scarfs.

The original Nymph struck me as a surprisingly stiff-sided canoe given its thin planking, a lot stiffer than my Bell canoe in straight Kevlar. I am a bit apprehensive about fairing the 1/8" planking (even though Nick told me there would be no problem if I was careful aligning the strips) so I may go to 5/32" or even 3/16". The nice thing about not using bead and cove edges is that I can make the planking any thickness I want. With the Northern white I don't think I'll notice a big weight difference, my novice epoxy technique will probably add the greatest amount of extra weight.

Hello, Battenkiller - If you haven't alredy done so, check out the two most recent issues of WoodenBoat - our host's lovely magazine. There are two articles by Nick about the building of Nymph in which he goes into nice detail. He also indicates that the boat can be built in two lengths by altering the station spacing.

In my experience, a longer boat of the same width (hull shape being the same, too...) feels to be a bit more stable because the you get a bit more "lever arm" moving the boyancy away from the paddler into the ends .

[Cuyahoga Chuck]

One thing to remember about Nick Schade is he has a LOT of experience and is quite artistic. One of his boats was exhibited at the Museum of Modern Art. What's "easy' to folks like him could be like humping a boulder up a hill to the rest of us.
Conventional stripping is a fairly expensive way to build a paddleboat and laying on a piece of Kevlar/carbon will really run up the cost.

[Battenkiller]

Well, this thread died before anybody got one built. I finally got ours finished and have much to tell but I have to back up and read all these posts first. I forgot about this thread and had to reinvent the wheel several times to arrive at many of the same conclusions that were already presented here. On many things, however, I made discoveries that contradict info here. Anyway, here are a few shots of our completed Nymph (named Katydid after my granddaughter's nickname) which we made at 11'. She finished out at just over 20# with some rather generous trim for durability and improved looks:

Here's Katydid as she sits in the lilies on a pond in the Adirondacks

http://img.photobucket.com/albums/v306/drfera/Web%20Linked%20Images/KatydidInTheLilies.jpg

Here's a closeup of her bow showing the cherry crotch breasthooks and sculpted quarter thwarts that were not in the original design. You can also see the flamed basswood we were able to find and use for the gunwales. These items added at least an extra pound (figured wood is often denser than the same cuts elsewhere on the tree) but we couldn't resist the improvement it made in the appearance.

http://img.photobucket.com/albums/v306/drfera/Web%20Linked%20Images/CloseupOfBow.jpg

Here's one last shot of my wife Rose and our granddaughter spending a relaxing (very relaxing for one of them) day on the water.

http://img.photobucket.com/albums/v306/drfera/Web%20Linked%20Images/IMG_3918.jpg

I'll try to start a build thread (unfortunately, after the fact) when I get a chance, but for now anyone interested in building this sweet looking (and handling) boat can check out the blog I started way back in the winter. Or feel free to contact me at any time.

http://battenkiller.blogspot.com/2008/05/building-small-double-paddle-pack-canoe.html

I'm not a very good blogger and as someone pointed out here somewhere, developing the blog was harder than building the boat. It is in reverse chronological order (I don't know if that is fixable) so you have to go to the index on the right to get to the proper sections. Also, I haven't got around to finishing it since first priority was to finish the boat. I may never get around to it, but I have tons of photos and info on the later steps that I can share if anyone is interested. I had a ball making this boat and I'd love to see a lot more of them out there.

[Canoez]

Battenkiller - you did a beautiful job on the boat. :D I look forward to seeing your blog about the building of her!

[Cuyahoga Chuck]

I am not a fan of short waterline paddleboats but what you did was a dynamite job. Congratulations.
Just noticed. No carbon/Kevlar inside.

[Battenkiller]

Thanks, guys, I really appreciate the compliments.

No Carbon/Kevlar hybrid cloth... not at $45/yd :eek: when the outside was done with 3.2 oz. that I paid $1.20/yd from Thayercraft. ;) I suspect that Nick used it for the stiffening effect of the carbon fiber as well as easy finishing of the inside and a modern look that complimented his design (although to me it looked a bit retro, kinda like an old Fender tweed amp).

We ended up using the graduated thicknesses I mentioned way back - 1/8" walnut for the tumblehome area, 5/32" basswood up to just past the turn of the bilge and 3/16" along the very bottom. Even so, I was alarmed at how flimsy the hull felt (it's my first stripper) until I put the cloth on the outside.

I also added a football shaped piece of 3.2 oz. on the inside to help eliminate oil canning which is all it really needed. Altogether, our boat has less weight in cloth than Nick's 10 footer, but quite a bit more weight in wood. Still, the boat was only 12 lbs. 12 oz. when she came off the form (glass, wet out coat and one hot coat on the outside). I faired away another 12 oz. on the inside, leaving her at 12 lbs even. The inside glassing added another three pounds IIRC. That means that all the trim added another 5 pounds, more than I had hoped for but still a pretty light boat and very strong for such light construction.

The extra 1/16" of wood on the bottom turns out to have been a good judgment call - a nominal increase in weight but a substantial increase in stiffness, my main concern before starting this boat.

Here's a link to another forum with a few shots of her glassed on the outside, getting weighed and getting her inside faired out.

http://www.myccr.com/SectionForums/viewtopic.php?f=49&t=29660&st=0&sk=t&sd=a&hilit=building+nymph&start=15

[jaredbeck]

Wow, gorgeous.

I'm still working on mine. Almost done.

http://building-a-canoe.blogspot.com

Thanks so much for sharing yours, batten.

[Battenkiller]

Wow, gorgeous.

I'm still working on mine. Almost done.

http://building-a-canoe.blogspot.com

Thanks so much for sharing yours, batten.

Thanks, Jared, and thanks for sharing your blog with us. Yours is going to look just as good when it is done. It's amazing to see what see what 4-5 coats of varnish can do to a smoothly sanded hull.;)

This was the hardest time for me, getting her last details together. The beginning was tough because I had this vision of a perfect boat. After the first several boneheaded blunders I realized that was never going to happen and progress went swiftly. After she was all sanded out and I realized that she was fair and that no one could see all the boo-boos (or that I had repaired them) I again started to get that hope for visual perfection and got stalled again.

Just keep slogging away. It took several coats of varnish before I got the hang of the stuff, but each one got sanded flat and the next coat got even better. By the fourth coat I was out of varnish and had simultaneously achieved an acceptable finish.

You might want to consider the kayak backrest like I used. I really hated to go with anything but wood but the kayak backrest is comfy and adjustable (easy to put on as well). Plus, it weighs a heck of a lot less. That's why I put in the quarter thwarts as the boat needs strength across the hull.

Also, Nick doesn't mention how to determine seat placement (he is extremely friendly on the phone, however, if you want to call him) so I decided to put threaded inserts about 1" apart so that final seat placement could be determined after the boat was on the water. That way I could achieve perfect trim and leave it adjustable for varying load conditions. I can send you a few photos of this stage and a technique I figured out for fitting the seat supports (they have to fit a compound curve) if you are interested.

Good luck with the rest of it. You're fairly local to the Adirondacks. If I see another Nymph on the water up there I'll come over and say hello.:)

[Canoez]

Also, Nick doesn't mention how to determine seat placement (he is extremely friendly on the phone, however, if you want to call him) so I decided to put threaded inserts about 1" apart so that final seat placement could be determined after the boat was on the water. That way I could achieve perfect trim and leave it adjustable for varying load conditions. I can send you a few photos of this stage and a technique I figured out for fitting the seat supports (they have to fit a compound curve) if you are interested.


Seat placement isn't usually that difficult. Once I get the gunnels and the decks installed, I take the canoe and balance it on a piece of PVC pipe that is perpendicular to the main axis of the canoe. Once I know the balance point, I put the front rail of the seat at that location or a bit aft of it (1-2") This usually works out well for most people's weight distribution. (Body trunk/legs)

If in doubt, put in temporary thwarts and put the boat in some water to determine where you like the seat. Some people prefer their solo boats to ride a bit "aft", so that's why I might move the front edge of the seat back that 1-2".

[rking842000]

I have built two Nick Shade boats during the past two years and found that the combination of Spanish Cedar and Brazilian Walnut tooled very similarly. I used a white pine as an offset line and felt was too soft beside either the Spanish Cedar or the Brazilian Walnut, so will not do that again.

Russ

[George Roberts]

"It seems like a schedule of 1/4" cedar strips with 4 oz. E-glass exterior and 6 oz. E-glass interior would be plenty strong, (much?) cheaper, easier to build, and would carry a negligible weight penalty. Anybody have any real data or other opinions about this?"

I have both real data and opinions.

I would use less wood and more of cloth relative to what the plans call for.

Kevlar/carbon runs about $30/yd for 5oz. Very heavy cloth for a small boat. (Mr. Shoddy does not do conversions between fabrics well at all.) There is some real nice 2oz carbon cloth around. Some nice 2oz kevlar also. Both are better deals and better choices. Multiple layers of 3oz satin e-glass are prehaps the best choice considering weight and cost.

1/8" wood strips are easy to work with. Perhaps a bit heavy for a boat that size. I would use .093 strips. I know people who would use .075 wood strips.

A finished boat that size should be well under the 15 pounds. (I build 17' kayaks that weight 15 pounds.)

[paladin]

If it's lightweight you're going for......and have an old canoe as a mold......wax the canoe, paint it with PVA, then paint it with a thin coat of epoxy.....
get a roll of brown market paper and cut it in 3-4 inch wide strips, paint one side with epoxy and lay it up double diagonal like with a veneered boat.....add one layer of 2 oz veil (carbon fibre), then 2 more layers of paper, then one of 2 oz e-glass.......you will need something the stiffen the gun'ls....and a piece of 1 x 1 airex with the glass over should suffice.....then your 5 year old can drag it to the water...vacuum bagging will only make it lighter....

[LarryR]

I can understand most of that schedule,
but what's the purpose of the PVA layer?

Very respectfully,
Larry

[Todd Bradshaw]

It's to make sure you're building a new hull.....rather than simply adding some rather curious reinforcing the one you're using for a mold - PVA is mold release.

[LarryR]

Thanks Todd,

As a woodworker and not recognizing the context significance, I read PVA as the acetate woodworking glue -- which made no sense, and I'd thought that mold release was the wax's function. A google search on "PVA mold release" located a good explanation.

Very respectfully,
Larry

[Battenkiller]

If it's lightweight you're going for......and have an old canoe as a mold......wax the canoe, paint it with PVA, then paint it with a thin coat of epoxy.....
get a roll of brown market paper and cut it in 3-4 inch wide strips, paint one side with epoxy and lay it up double diagonal like with a veneered boat.....add one layer of 2 oz veil (carbon fibre), then 2 more layers of paper, then one of 2 oz e-glass.......you will need something the stiffen the gun'ls....and a piece of 1 x 1 airex with the glass over should suffice.....then your 5 year old can drag it to the water...vacuum bagging will only make it lighter....

Great Idea! I'll have to post that one over on the "CompositeBoat" forum.:D

Really, regarding going down to less than 1/8" on a stripper, I can't see it happening for a wider boat - too much flex and oil canning. Nymph is 24" at the 4" waterline with a rather flattish bottom, concave actually just before she vees at the keel line.

Check out her body plan:

http://www.guillemot-kayaks.com/guillemot/node/567/draw

Without the use of a super stiff fiber like graphite she would flex too much when loaded. A very narrow kayak might be able to go to have a 3/32" bottom... if it had a round bottom. The boat I built has 3/16" basswood on the bottom and 3 layers of 3.2 oz. glass (2 on the inside) and I feel strongly that she would flex severely at 1/8" without the hybrid cloth to stiffen her up.

I agree that the wood doesn't add much strength, but the thickness of the wood adds stiffness to the sandwich, the only real requirement for a boat like this that will only see light flat water usage. I plan on building this one again at 10' and 1/8" planking on the bottom tapering to 1/16" from the turn of the bilge on up. I will use northern white instead of basswood and not use walnut in the tumblehome area. Satin glass, an ultralight molded composite seat, thinner double tapered semi-hollow gunwales, smaller and less dense decks, a single thwart amidships and the elimination of external stems should get me in the 12 pound range... maybe even lighter.

[JimConlin]

Had you thought of using a lighter core, like Core-Cell?
3/8" of 5# density Core-Cell would be MUCH stiffer than 1/8" cedar, somewhat less ding-resistant and, allowing for more resin penetration, weigh about same.

[Battenkiller]

Had you thought of using a lighter core, like Core-Cell?
3/8" of 5# density Core-Cell would be MUCH stiffer than 1/8" cedar, somewhat less ding-resistant and, allowing for more resin penetration, weigh about same.

Well, I kinda like the idea of a wooden boat.

I have, however, thought of going down to 3/32" and adding thin half-ribs of Port Orford every few inches to stiffen up the bottom. Seems like a lot of work, but hey, I have all the time in the world.

Another thing I thought of is to use my ROS on the inside with a halogen worklight on the outside of the boat to monitor the thickness. Light shows through wood pretty good once it gets down below 1/8". I know a guy that turns wooden hats (that's right, hats) using that method. He works to incredible tolerances in green wood, all by eye aided by the translucency of the wood.