: . . . i'm planning a bit ahead and am wondering if useing red cedar, exclusively,
: for the frame of a sof is do-able. or is it too weak? . . . i have lots of red cedar in
: my stash and thought i might use it if it's strong enough. . .

Of course it is do-able. it is not s question of whether the wood is weak, it is a question of whether the size and shape you need is too weak. Let me put it another way: If you need to hang a firebucket on a wooden peg, do you make your peg from an oak toothpick, or from a balsa 2x4? Now we all know that size for size oak is stronger than balsa. But in the appropriate sizes a balsa part can be made that is stronger than an oak part (as in bals 2x4 vs. oak toothpick). Or it can be lighter. That balsa part will probably be a good deal larger than the oak part, though.

OK, so with cedar, the material is light weight, soft, and easy to work. If you are dealing with something that is going to be battered a lot, you want a tougher wood -- one more resistant to pounding. But otherwise, you can make a part from cedar that will be as strong as any oak part. It will just be physically larger.

For example: If your plans call for using chines (the longitudinal elements) on your boat that are 1/2 by 3/4 oak, you could probably use 3/4 by 1 inch cedar, or even 1 x 1-1/4 inch cedar.

The nominal 5/4 cedar I usually buy is originally destined to be decking material, and measures about an even inch in thickness. If that thickness is strong enough to support my weight on my backyard deck, it is definitely strong enough to hold my weight on the water!

In some cases there are certain properties needed which only a few hardwoods can provide. In those cases you must either go with the specs, or you must design around them to use other materials. For example, where a board must be bent in a curve it is common to use woods which bend easily either dry, or with steam. But if none of these types of wood are available, you could also build up the piece by laminating many layers of easily bent, thin, strips of some other wood species.

So, go with your cedar, but make the parts a bit bigger, or as they say at the major fast food franchises: "Upsize" 'em.

The Walrus, as described in his book by George Putz, has been built of red cedar, using the sizes specified in the book, so SOF boats can be, and certainly have been, built from red cedar.

hope this helps.

PGJ