Backsaw blade straightening

[Eric Sanford]

Hi all,

I recently picked up an older Disston backsaw off ebay. When I got it I discovered that the blade has a slight curve in it. The spine is straight, yet the blade curves along the cutting edge from front to back. I don't have much experience rehabbing tools, but would obviously like to get this saw in usable order. Do you have any suggestions on how I can fix the blade?

I should point out that I've tried some of the obvious (to me) solutions like using my hands to try to bend it back. I also used my bench vise to try to press it back into shape, including using blocks in counter-curve positions. Still no luck.

TIA
Eric

[harry strasil]

Eric, there are 3 possibilities,

1.sometimes when a person bends a backsaw blade while it is in the cut it pulls the blade out of the spine a little on each end or the middle and this bows the blade. to check and see if this is the cause, put the saw teeth down on a heavy piece of oak and gently rap the spine on the top rounded edge in about 4 places along the spine with a wood mallett, do not use a metal hammer as this will have a tendency to spread the spine and thus loosen the blade in the spine.

2.take a 3/4 by 1-1/2 piece of scrap pine about a foot long and saw a kerf the depth of the saw crossways in one end. Clamp the spine in a vice teeth up and slide the pine down over the blade and then use a clamp to clamp the pine piece abaout 2/3 of the way down from the teeth, then gently push on the pine piece to take the bow out, be careful it is easy to go to much and kink the blade.


3.Take it to some old timer who knows what he is doing and let him hammer stretch it back straight.

[Eric Sanford]

Thanks very much for the suggestions. I'll give them a try.

Eric

[Alan Turner]

Hi all,

I recently picked up an older Disston backsaw off ebay. When I got it I discovered that the blade has a slight curve in it. The spine is straight, yet the blade curves along the cutting edge from front to back. I don't have much experience rehabbing tools, but would obviously like to get this saw in usable order. Do you have any suggestions on how I can fix the blade?

I should point out that I've tried some of the obvious (to me) solutions like using my hands to try to bend it back. I also used my bench vise to try to press it back into shape, including using blocks in counter-curve positions. Still no luck.

TIA
Eric

Eric,
I couldn't do it myself, but if I am not mistaken, Tom Law, of Maryland, knows how to hammer a saw straight. He certainly can file and set them. I have sent him a number of saws, and they came back quickly, and perfect. Make a rip cut on a tenon with a good saw he has sharpened, and you will think you are in heavan. When I send him a saw that is new to me, I have him file it, specify rip or crosscut, and tell him how much set I want, such as small, med., etc. You could contact him and ask if he will straighten your back saw. He will be glad to talk to you. He is a gentleman in all respects. Good luck.
Alan

[Eric Sanford]

Thanks, Alan. I know of Tom Law although I've not yet sent him anything. If I have no luck, that will be the next option.

Eric

[Alan Turner]

Thanks, Alan. I know of Tom Law although I've not yet sent him anything. If I have no luck, that will be the next option.

Eric

Eric
I called Tom Law for another reason, and asked him your question. Here was his answer. If the blade is bent, such as in a gentle curve, he can probably straighten it with no problem. If there is a kink, or sharp bend, probably not, althugh if it is just at the teeth, he can file new teeth to get to fresh metal. He cannot straighten a cast steel back (at the top of the saw) if it is bent. I also asked this question for my future reference as well, since I sometimes see a nice saw, but for the gentle bend, and have stayed away from them.
Let us know how you do with yours.