McKee Craft sole replacement/rebuild

[Mad Dog]

No ridicule here.

This is the way I understand the differences. Think of the difference between laminated wood and whole boards. In the laminated wood the grain of each ply should run in opposition to the the ply it is mated with. "Stick" wood has the grain running all the same direction, end to end. While the stick is very strong you have to take it's weight with it. In a laminated part you get the strength in less weight. I think about the laminated trusses and such used in wood frame construction. They use the engineered trusses for load bearing spans which require less wood and less space for the same strength.

In the stringer application you get the added strength, weigh savings (maybe not significant), and you get the benefit of overlapping slices ( a 12' stringer 1.5" thick, 3/4" ply - two 8' pieces two 4' pieces glued with joints offset, very strong). Also, I find that fitting a plywood part is much easier than stick.

MD

[Cracker Larry]

The other advantage to ply is dimensional stability. The laminated pieces don't warp, twist or cup.

[tech_support]

I would use plywood for the frames/stringers for the main reason CL say; its stable.

For those small parts you can use the best quality exterior grade plywood if you cannot get marinegrade. If you go the exterior plywood route you had better cover every surface with glass and several coats of epoxy.

[TomW]

You won't find the woods you need at HD or Lowe's. They will be at specialty lumber yards. Marine fir should be easy to find in your neck of the woods. Or if you can wait a week and 1/2 you can come meet all the guys down in CR and Joel can bring you some Meranti 6088 which will be lighter plus all your fiberglass supplies. The cookout and all is on Sat 24 April in Crystal River. I believe it is only 3 hrs from Tallahassee and will save you having to search around for the right supplies plus you get a free meal.

See the Anything Else section for the two posts. If you want you can even stay and fish Saturday afternoon.

Tom

[sam03v]

I'm trying to put together my material list and have a question. How thick should the frames between the stringers be? Same question for the front and back bulkheads and the two new stringers? The center stringer is currently 1.5" wide( the width of a standard 2x4) and I'm going to keep that width, but I'm thinking the two new stringers don't need to be that wide.

The local lumber yard sells 3/8" marine grade and 3/4"(its' fir by the way), for about $65 a sheet.

thanks in advance.

[tech_support]

3/8" is fine. They get glassed to the bottom and sides with Bixial tape. Epoxy glue cleats to the top edges of the frames to give more glue area for when you bed down the sole to the tops of the frames. Everything gets at least two coats of epoxy.

[sam03v]

Biaxial tape doesn't really have any tape on it right? I can get some free fiberglass that looks alot like the biax pictures i've seen on the web. I don't know what weight it is though. Its' on a huge roll that is 2' wide. I can take all I want for free so it would be good if I could use it. Is there any way to tell if fiberglass is biaxial or not?

thanks again.

[TomW]

Biaxial tape or cloth has fibers running in opposite directions. It is a more open weave than fiberglass cloth. Take a look in the Boat Building Supplies section, the pictures are not real good there but will give some idea of what to look for. The other thing to watch out for is if the material you can get your hands on is for poly it may have an additive in it that makes it non-compatible with epoxy, it helps bond the poly, but rejects the epoxy.

Tom

[sam03v]

I weighed a 6" x6" piece of the glass and it was 6.75 grams, which from my "calculations" works out to be 8oz/ yard. Assuming/hoping that this stuff doesn't have the additive on it would it work for the stringers and sole?

[TomW]

That should be okay. Do two overlapping layers. You can do a test once you get your epoxy mix up a tablespoon or so and use your 6x6" peice and glue all but enough to grab down to a scrap peice of wood if it sticks and you can't pull it up your golden.

Tom