Bob -

1. Super duper fingerboards. This probably won't hold your cut absolutely straight, but it IS a SOF so you have much greater leeway, and you can clean things up pretty easily with a plane. Make your boards very heavy duty, and use a helper on the back end of the saw.

2. Rip the board using a bandsaw and a fence. This is probably safest - just make sure you have two people to guide it, and you practice on a throwaway. Again, you'll have to clean everything up with a plane, and you might not have a bandsaw, but it's a thought.

3. Carefully, VERY carefully screw the board down to a sacrifical peice of plywood, MDF, or even another 2x4, making VERY sure that your saw kerf will miss all the screws. This should straighten the board out - rip as normal. Don't hit the screws. Start with the exposed side - after that side's done, flip it, and don't hit the screws. Did I mention not hitting the screws?

Well, I'm doubt that any of these ideas will give you a perfect cut, and I'm not even convinced of their safety (the bandsaw seems pretty innocuous).

Good luck, and don't hit the screws.

N

: I finished building a router jig to cut the rib mortises in the gunwales of
: the greenlander I have underway, what i did to get more sheer was to let
: the 2x4 im using sit out for the last two (very wet) weeks with about 60
: lbs. of scrap iron hanging from it this worked very well. I want to use my
: 7 1/2" freud thin kerf to split the 2x4 after i rout the mortises,
: this will take two passes on my table saw. Can any one point out at any
: problems I'm liable to run into? I've probably got 3" of curve in
: 16'. Thanks.
: Bob