Originally Posted by
RayG
+1 for pretty much what Ian has already said, the ideal amount of set depends a lot on what you are doing, the type of timber etc.. for fine toothed dovetail saws you only want a couple of thou so that you get a nice fine kerf, if you are cutting deep into green timber you'll want a lot more set and less tpi. My rule of thumb is to use the absolute minimum of set. and keep it as even as possible. You can always do the paper and vise trick to even the set. If you don't have a smooth jawed vise, you could use a couple of pieces of heavy steel.
Brittle teeth is another matter all together, it's a long debated topic about old saws having brittle teeth.. and some older saws seem to snap teeth like crazy. I've heard theories from hydrogen embrittlement, to work hardening, etc.. and all sorts, but the bottom line is just take it easy and don't over do it. If you break one or two teeth, don't worry too much it won't affect the way the saw cuts, and they will grow back over time as it's rejointed, if it's missing more than just one or two, I'd probably re-joint it :)
Also, look closely at the gullets for cracking.. if the gullets are cracked, it might pay to re-joint past the cracks and cut new teeth.. depends a bit on the saw, and how keen you are.
Regards
Ray
PS There have been organized group buys for saw nuts, slit brass and saw plate in the past, so there must be some still out there hiding in the back of the workshop gathering dust on someone's shelf.. :)