Plwood Choices to start building a 36" catamaran

[Petee_c]

I've got some free time to go and buy some wood to start a long awaited catamaran build. There is a place in Brantford (about 65km) away from me that is called aircraftspruce that has thin plywoods in stock. I plan to drive there this Saturday morning.

http://www.modelbouw.gompy.net/boott...36inch_mod.pdf is a link to the plan I am using.

I need help picking out which wood to buy. I figure I need two 2x4' pieces to do the frame and stringers (3mm or 1/8" thick), and probably two 2x4 pieces to skin the boat (1.5mm or 1/16th" thick)

Here are my choice according to their website.

Finnish Birch Aircraft Ply
1/8" x 2 x 4 = $46.50 (5 ply)

Domestic Birch Ply
1/8" x 2 x 4 = $33.50 (? 3ply) MIL-P-6070

Lite - Ply
1/8" x 4 x 8' = $49.65 (3 ply)

Domestic MIL-P-6070 Aircraft Mahogany
1/8" x 2 x4 = $47.50


For skinning the catamaran, they have a the Domestic Birch Ply , Finnish Aircraft Birch Ply, Domestic Mahogany Aircraft Ply available in 1/16" thickness in 2x4' sheets between $26 and $36 dollars

Canadian prices - keep in mind I live in Canada so take Domestic as meaning North American...

Is there a big difference in strength for building a 40-50mph catamaran? Noticeable difference in weight? I have twin 3674motors and 120 amp esc's to power this boat.

Thanks for helping a newbie out.

Peter

[boredom.is.me]

Bump

[ray schrauwen]

I would say you want the flattest stuff possible that will warp the least. I don't know plywood but they will. For covering you want a nice smooth finish to make life easier.

Guessing that finished birch ply for sheeting and domestic birch ply for bulkheads and stringers.

Is that Finnish as in Finland or finish?

[grsboats]

Your choices are ok but also consider apply thin fibeglass (1/2 or 3/4 oz) in the outside if you know how to do it...it will make a big difference in the end.Gill

[Petee_c]

I ended up getting the 1/8th" Finnish aircraft ply for the frame.

[Petee_c]

I am almost done cutting out the frame and stringer bits. I'll go on Saturday to look at the different 1/16" plywoods to skin the boat. Just doing some visualizations in my head, I am thinking one 2x4' sheet should skin a 36" long cat with a beam of 13.5"...

Now to research glues and epoxies...