Back saw plate streightening

[Zahid Naqvi]

I know this has been discussed a few times here, and the detailed write ups by George and Bob are indeed very valuable. I have a slightly different problem. I have a couple of back saws which have a slight "wave" across the length of the blade on the business end. The spline is dead straight. In one case the spline is epoxied in so I can't move it in anyway, the other has the spine hammered pretty hard and from what I can tell the blade is touching the spline on both ends so it is not the case of the blade crawling out of the back. I don't have the heavy hammer required by the Smalser approach or a metal vise/anvil to use as the base for striking. I have a run of the mill hammer and I can probably use the concrete floor as the work surface.
So do I have any option to try and fix these two saws?

[george wilson]

You could try heating just the back of the saw with a torch to melt the epoxy. Then,clamp the end of the blade in a metal vise and hammer the end if the back to jerk the blade straight..

To not heat the blade,try laying the saw in a metal vise so just the back is above the jaws. Then,you can heat the back without heating the blade. Move the saw back and forth in the vise until you have heated the whole back to soften the epoxy. Then,jerk the blade straight.

I am not certain this would work,but it is all I can think of.

[David Weaver]

You should never have to hammer the blade in a backsaw.

If you can't get the plate out as george mentions, I would use the trick he provided in previous posts - twisting (not bending) the spine slightly while the butt end of the saw is in a vise.

A little bit of a twist of the spine can pull minor gradual waves out of the back of a saw. If it doesn't work, you can put it back like it was.

[george wilson]

You are correct,David. I am not too sharp this A.M.,and am forgetting my old tricks!:)

[Sean Richards]

You should never have to hammer the blade in a backsaw.

If you can't get the plate out as george mentions, I would use the trick he provided in previous posts - twisting (not bending) the spine slightly while the butt end of the saw is in a vise.

A little bit of a twist of the spine can pull minor gradual waves out of the back of a saw. If it doesn't work, you can put it back like it was.

Twisting the spine works quite well. I clamp an inch or so of the spine in a vise and then use a crescent spanner to twist.

[David Weaver]

You are correct,David. I am not too sharp this A.M.,and am forgetting my old tricks!:)

It's worked for me with several old english saws and with new saw kits where the blade isn't perfect after it's first jammed into the back and jostled up and down looking for a point where it's straight.

[george wilson]

We slightly twisted some of the backs on the back saws we made for the historic area in order to get the blades straighter. It doesn't even show on the back,unless your wavy blades are very wavy.

[Zahid Naqvi]

So essentially at the end of this exercise I will end up with a slightly twisted back but a straight business end. I had already tried clamp, hammer sequence to snap the blade back in, it removed the twist some but not all of it.