Which Lumber?

[holly]

Hello again,
I would like to get opinions on lumber for stringers for a 22' catamaran.
I can get either Cypress or Yellow Pine the corrrect size and for the same price. ( .65 a foot).
So let's see who has knowledge of lumber for stringers!
Thanks for all your help. I do appreciate it!
Holly

[TerryKing]

http://www.boatdesign.net/wiki/Mater...t_Construction

[holly]

You sound like you are having a nice cruise!
Fairwinds my friend, Holly N4KXG

[alan white]

Either wood is just perfect. By stringers, I assume you mean chine logs and other such things, since a cat of that size wouldn't need longitudinal framing parts between corners. Perhaps the yellow pine will hold fasteners better, which is significant if you are using fasteners.
No matter what you use for stringers, you should use rot-resistant woods. Yellow pine and cypress are therefore both good choices. 65 cents a foot sounds very cheap, but you must be talking about ready-made pieces of the dimension required (linear feet) rather than board feet. Maybe the pieces are 3/4" x 1 1/2", which would be about the dimension of a stringer for such a boat.
Hand pick the pieces for straight grain. I see a lot of folks framing boats with wild-grained wood, and it does make a big difference in strength to choose your wood carefully. What often causes a stress break in a piece of wood can be blamed entirely on the run of the grain.

Alan

[holly]

Thank-you Alan, very good information from the forum as usual!
Yes, the stringers will be 7/16X 1 1/4" for the two 22' hulls.
The shop will make the right size from their stock of yellow pine or cypress for me. I may as well have them make my frames there as well, 3/4"x 1 3/4".
Have a great day..holly