Handsaw rehab question

[Jerrimy Snook]

What do you do with a handsaw that has teeth that seem to have been crystallized? Setting the teeth may break them and sometimes they are brittle enough that filing or using the saw will break teeth. Is it possible to temper, anneal or whatever to make the saw usable again... or is the saw only suited for painting and hanging on a wall?

[David Weaver]

What model of saw is it?

Saws are generally cheap enough that it's usually a lot easier to just go get a saw that is correctly tempered.

[Jerrimy Snook]

The saws were customer's saws and they were returned dull. If I remember correctly the saws most likely to be crystallized are dark in color, no shine, and only a medallion as a means of identification. I suppose the cause of crystallization, quality of the saw, and value to the owner would all be factors to consider when trying to rehab the saw. If the saw was hardened by grinding, then re-toothing would take care of the brittle teeth. But a previous thread got me thinking.... If a saw could be tempered in order to file, is it possible to rehab the old crystallized saw.

[george wilson]

Saws don't crystallize. Are you dealing with a saw that has induction hardened teeth? The tooth line of such saws is dark from the induction hardening. They are not meant to be sharpened.

[Jonathan McCullough]

Crystalization is a term that I've only ever seen in old Foley Belsaw manuals. What I think they meant was surface oxidation on the teeth from left over pine resin. From what I recall, the manuals stated that you couldn't retooth or resharpen those saws, which never made sense to me. When you clean saws like that with mineral spirits and sandpaper, they smell like rosin for violin bows. You can also sharpen them. Pictures help!

[Pedder Petersen]

Its easy to test, if the teeth are hardened: a file will slip. In that case I would - and I tell you not to do with your saws - temper the teeth with the heat gun to blue color. Don't try this with you beloved saw, it could warp your blade. ;)

When the blade is dark, one can think, that there was heavy rust on it before and the rust was removed with acid. And the rust and maybe the acid sometimes seems to destroy the structur of the blade. If that is the case, I would try to grind the teeth away and start with fresh metal.

Cheers
Pedder