How much set is too much set?

I got an email today from a local customer who was concerned about the excessive set on his rip saw. This is an all too common malady on old saws. You can see that this saw would cut a kerf almost three times as wide as the saw plate….too much to say the least.

Most saws used to cut dry hard and soft woods for furniture making need set equal to 10% of the thickness of the plate per side. So for a typical rip saw with a 0.042 inch thick plate, that means about 4 or 5 thousandths of an inch (0.004 to 0.005) of set per side. That’s not a lot of set. This poor saw looks like it was set to rip a slab of water-logged pine fresh from the swamp.

So what to do about an over set saw? Well, for cases where the set is just a bit heavy, stoning the side of the teeth with a fine diamond hone (I like the DMT 1200 grit) or oil stone can remove the unwanted material from the sides of the teeth. But you can easily over do it and cause other problems. You can also gingerly reverse a bit of the set with a regular saw set or setting hammer. This is not recommended for the unfamiliar as you can easily break or crack the teeth. Setting saw teeth causes work hardening, which makes the steel more brittle. If you bend them back the other way, that doesn’t bode well for them, so I generally discourage this.

Unfortunately, the only safe and sure-fire way to fix a saw like this is to joint the saw below the set and re-file new teeth. This is labor intensive, but when you’re done, you’ll have a saw that will sing. :)

-Matt

 

 

5 Responses to “How much set is too much set?”

  1. Paul Korman says:

    Matt, how about using a machinist vise like a Kurt to flatten (remove) the set or better yet use a couple of sheets of paper on each side to achieve the required set a la the Mike Wenzloff method. The video is on C. Schwarz blog at http://www.popularwoodworking.com/article/get-a-consistent-set-on-your-saw-with-paper.

    • matt says:

      Paul

      I’ve seen Mike use this trick. I’ve never had access to a vise like that, so i can’t recommend it one way or the other. I would be a bit skeptical of bending that much set out of teeth like those shown above….that’s just too far to bend steel back without damaging them.

      Matt

  2. Mark Schreiber says:

    If you use the vise method, even if you do not remove all the set, perhaps enough set is reduced to make the saw serviceable again.

  3. Joe F says:

    I find it’s worse on rips so if your going to change the rake angle you’d already be jointing it deeper then normally so it’s not loss.

    I feel I must add retoothing with a foley would also get you back in track. ;-)


Leave a Reply