: 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.

The biggest problem I can see is that you are going to try to cut this in just two passes with a thin blade. The bent wood is very likely to bind the blade, stall the saw, or maybe bend the blade. To avoid this, use the method employed for cutting circles on a table saw: many passes with the cut increased slightly on each pass.

Try setting the blade to cut only 1/4 of an inch on the first pass. Cut the bottom, and then flip the wood and cut the top with the same depth of cut. Then raise the blade another 1/4 inch and make tow more passes. Continue the process with small increases in the blade height until you get through the board. if you get any burning or the feed is difficult, lower the blade so you get a smaller cut and just make many more passes. It is not safe to rush this. Besides, a few more passes will be just another couple of minutes.

You will NOT get a thin kerf cutting a curved piece of wood. Effectively the blade is cutting the wood at an angle. The leading edge of the blade will be cutting, and widening the kerf to one side, while the trailing edge will be cutting and widening the kerf on the other side.

As the trailing edge of the blade has the teeth coming up from under the table, and biting into the wood above -- forcing the wood off of the table, you want to be sure that you hold that wood dowm very securely.

If the entire length of the board is an even thickness You can clamp a piece of wood to your fence which will ride 1/8th to 1/16th of an inch above the part you are cutting. This will be stronger than fingerboards, which can get shattered when a 2x4 gets kicked back.

A bandsaw is really the tool for working with curved cuts in curved wood, but sometimes you have to use what tools you have.

Hope this helps

PGJ