Boat Building

[D Nichols]

Good day, wondering if anyone has ever used or thought to use Coosa board in race boat construction and if not could you explain why. Thank you

[ZUL8TR]

I never have used the Coosa material.

My quick review: it appears to have some good strength specs, is water proof, very flexible, accepts selected adhesives, holds fasteners well, essentially rot proof, weighs 40 to 60% less that comparable plywood sizes.

Is not UV tolerant, limited thickness availability, might be too flexible so span spacing critical, not as pretty as wood for bright finish, costs 2 to 3 times more than plywood of same dimensions, since much lighter might need more lead to meet race class weight spec.

Could be used in selected areas.

Race boats usually have a limited life span and if cost is a concern plywood (like Okume) appears to be a better choice.

If you like natural wood look the answer is obvious.

[D Nichols]

Thanks for the reply and good day to you Sir. Thought this coosa board might work well for stringers and so forth due to it being so rigid and light. Found out some builders are even using this material for building transoms and hanging 200 + motors on. I used for re doing bottom of stern seat as ply was rotted. Impressive material.

[Albert]

I know the user Addvanced on here has replaced whole transoms and I believe stringers with it as well on some performance boats, one of which is getting a 250hp outboard hung off the back. I’m not sure how much is to be gained on a small hydro but on an inboard boat I’d be having a serious look at it.

[ZUL8TR]

Agree, not much gain on the small hydros . I have used very knot free white wood (spruce) for all my race boat frame work never any issues if carpentry done well. I have used Weldwood water based glue in the early days as well as epoxy later on and both worked well. Weldwood requires great fitting carpentry, epoxy you can have some leeway but not much. I like the epoxy as a complete cover sealant than varnish for UV protect or auto 2 part urethane as desired, varnish A + for great looking wood but much more work, and need to know how to apply ( I do no spray).