Strip Boats-Flute or no flute

[Jim Creech]

Dan,
I wish you well on rolling bevels however I think you will come to regret that decision. While beveling works well on thicker planked hulls where hull strength is derived from transverse frames,there is little room for error on 1/4" thick planking and no frames. B & C does offer a degree of lateral support not found in a rolling bevel. B&C provides a larger gluing surface, is pretty much self aligning and eliminates the possibility of a "Faux Pax" with the plane when you accidently over bevel. The cove also makes a nice little trough for the glue to lie in.
You might want to trade that $600 router for a comfortable "Moaning Chair"
Good Luck!

[Dan Fera]

Dan,
I wish you well on rolling bevels however I think you will come to regret that decision. While beveling works well on thicker planked hulls where hull strength is derived from transverse frames,there is little room for error on 1/4" thick planking and no frames. B & C does offer a degree of lateral support not found in a rolling bevel. B&C provides a larger gluing surface, is pretty much self aligning and eliminates the possibility of a "Faux Pax" with the plane when you accidently over bevel. The cove also makes a nice little trough for the glue to lie in.
You might want to trade that $600 router for a comfortable "Moaning Chair"
Good Luck!

Actually, a cove and bead is not at all like a ball and socket type joint and is only self aligning when the pieces fit together without an angle (180º to each other). The farther you get from 180º the worse the fit will be. At 90º no part of the joint will be closed while a mitered joint fit at the same angle will be 1.4 times as deep as the wood is thick.

Add in the twist present at the ends to the hull curvature and... well, show me some photos of tight joints in these areas. I haven't seen any nor can I visualize how they are possible. I have drawn these things out at 4X life size and they simply can't fit flush at these points.

Musical instrument tops and backs (always less that 1/4", often only about .08" on a classical guitar) have always been edge glued without the benefit of any sort of fancy joinery. I have been in the business of repairing these for over 30 years. Only rarely does this joint ever separate and when it does it can be attributed to poor fitting during building or bad glue (quality control wasn't too good 300 years ago).

Cracks on the sames parts almost always occur in another area of the plate, and since the wood is perfectly quartered to begin with, these cracks are always straight up and down through the thickness. I repair them simply by working high grade hot hide glue into the crack and clamping them across the plate. I have never known a crack I have repaired in this manner to come apart, they always crack somewhere else. Modern aliphatic resin glues are reputedly much stronger than old fashioned hide glue (although I tend to doubt that as well) so I am not worried at all about the strength of the glue line itself.

Besides, I plan to cover the entire boat with 6 oz. fiberglass cloth and epoxy resin. That should provide all the strength necessary to keep it together. If I hit a rock hard enough to cause a crack in the wood itself, it will most likely occur in an area other than the glue line. The same thing would happen with a cove and bead joint, so what would I gain by using it?

I do like the little glue trough in the cove, however, but I will just have to be a little more careful with the application and I should be fine.

[Bob Smalser]

Let's not make rolling bevels any more difficult than they are, either.

All that's required is to install the squared strip a tad overlong at stem and transom, then cut the bevel using a shoulder plane, keeping it on a 90-degree tangent to the molds. As the molds curve outward into beam or inward into tumblehome, so does the plane and resulting bevel.



If the plank lands in a stem rabbet, then take the plane's nose off, switching to its chisel plane mode. Or simply use a chisel if you don't have a chisel plane.

On a larger traditional stripper from 6/4 square edgenailed strips, builders simply countersank the nails and used a Stanley #10 rabbet plane to bevel the strip 90 degrees to the curve of the molds.

[Dan Fera]

Let's not make rolling bevels any more difficult than they are, either.

Quite!

Everybody gets all worried before they try a new technique and then sweats for a few days trying to invent a jig to get out of the handwork. Yesterday afternoon I made 28 3" scarfs on 3/16" walnut strips in well under two hours, all by hand with a razor sharp 2" Witherby socket chisel and my LN 102 to finish. No layout lines except for a line at the 3" mark. Every one of them perfect as if done in a jig but with a better gluing surface than a router would leave. It would have taken me at least a few hours to make and set up a scarfing jig with all the strips marked and placed in it and then have to cut the scarfs with a router or big planer or belt sander or whatever, but they wouldn't come out as nice and the fun factor would have been zero. If I had a boat factory, maybe that would be the way to go, but for a one-off? No way.

Want to get good at hand scarfing? Just get a bunch of strips and clamp 'em down to the edge of a board held in your vice and give it a go. Nowhere near as hard as you think.

Yeah, rolling bevels on edge fastened planks should be a breeze if done just as Bob S. described. Nowhere near as bad as lap bevels, where the angle has to be taken off each station mold with a sliding bevel and then transferred to the plank at the station mold spacing, cut to the correct angle and then blended together at the bench into one long rolling bevel exactly the same width throughout. And even those aren't so bad once you've done half a dozen. They can easily be done in place with a small straightedge held against the lining marks on the molds and the attached plank to get the correct angles. Still haven't tried the double lap bevels required for the Rangeley I'm going to build this summer, but I won't let them intimidate me either.

Anyway, sorry to get so far off track. Obviously, I'm convinced that edge jointing is the way to go on a stripper. If I'm wrong, I'll find out in a hurry. The "Moaning Chair" is a familiar resting spot in the Fera workshop. Just not sure what I'll do then since I intend to finish the strips to 5/32"

[Jim Creech]

Is that 5/32" finished hull thickness or plank thickness prior to planking?
Sounds kinda thin to me unless this is finished thickness after fairing.

I too have been doing luthier work for about as long as you have and I feel your pain. A good "Moaning Chair" should be a standard fixture in all shops!

[Dan Fera]

Is that 5/32" finished hull thickness or plank thickness prior to planking?
Sounds kinda thin to me unless this is finished thickness after fairing.

I too have been doing luthier work for about as long as you have and I feel your pain. A good "Moaning Chair" should be a standard fixture in all shops!

The boat is Nick Shade's pack canoe Nymph. Plans and detailed instructions were published in Wooden Boat magazine recently. He made the prototype with 1/8" basswood planking. He also used 6 oz. Kevlar/carbon fiber hybrid cloth on the inside for extra strength and rigidity. I saw the prototype at the Wooden Boat show in Mystic last year. It was fair and quite attractive, weighing in at 16 pounds for a 10' boat (mine will be stretched to 11'). The hybrid cloth on the inside was unexpectedly handsome, kind of like an old tweed guitar amp.

He built his on station molds spaced 10" apart. Mine will be 11" apart. For that reason, plus my unwillingness to spend $45/yd for the more rigid layup, I decided to go a little thicker with the planking to make sure it stays fair between the station molds. The walnut shouldered tumblehome area will be planed to 1/8" but the sides will be 5/32" basswood and I might go to 3/16" on the bottom. My main concern is to prevent oilcanning, not to make a tough hull. It will be used by my wife for puttering around on the local flat water creek and for day and weekend solo tripping on flat water only.

If the bottom feels sufficiently rigid after I have faired it out. I may actually go with 1678 E-glass which is only 3.2 oz. but supposedly has almost the strength of S-glass. The goal is to keep it well under 20# and baby it a bit more than is usual.

My graduated hull thickness is only possible to achieve by using edge glued planks, but Nick Shade's boat was laid up the same way and he sees no problem with the method (he's got just a wee bit more experience than I do).

My next stripper is a copy of a Bell Wildfire. The plan is for that boat to be 3/16" basswood with a walnut shouldered tumblehome area. I intend to use bead and cove on that one to give the method a fair try. I'm always open to anything that works best, but I have a strong predilection for using my hand tool skills whenever I can. Much more enjoyable and quieter as well.

Glad to meet another brother of the cloth here on the forum. Luthiers are a nutty breed in general, I think we're all masochists at heart. Boat building is so relaxing by comparison. Just out of curiosity, what area of lutherie do you specialize in?

[Jim Creech]

Sounds like you have done more homework than originally implied.
Keep us posted (with pictures of course). Most of my Kevlar experience has been with QA/NDE work on NASA projects. While this is pretty amazing stuff I am partial good ole wood grain.
As for luthier work,for years Ilimited myself to guitars (repairs, restoration etc) but for the past few years I have been swamped with violin work. Mostly school orchestra instruments. Some of the students are DEATH 80 on a violin or cello. I also have some "adult" customers that I am firmly convinced could destroy an anvil with a rubber mallet!