Brass back saw not perfectly straight, still ok?
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- This topic has 12 replies, 6 voices, and was last updated 5 years, 11 months ago by Philip Adams.
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3 April 2018 at 7:52 am #516712
Hey all.
I just bought a 16tpi brass backed tyzack tennon saw. Up till now I’ve been using a spear and Jackson 12tpi for my dovetails. I’d hopped a few more tpi night help with accuracy. Unfortunately the saw isn’t perfectly straight like it would have been new. The saw looks pre ww2 and of good quality but I could be wrong. Looking along the length(down the teeth side) there is perhaps a deviation from true of about the width of the saw plate. Is this likely to plague the accuracy of my cuts?
I’m yet to sharpen and use it and being only a beginner I’m trying to minimise possible reasons for inaccuracy.Thanks
3 April 2018 at 10:11 am #516734If your brass back is a folded one the Odds are there is nothing wrong with your saw except the tension on the plate. There are a couple ways to deal with it.
Paul’s method:
And another method from bad axe saws:
If one method doesn’t work for you, the o ther probably will.
Your TYZAK brass back is probably a folded one and just holds the plate with tension. So both methods should work.
The second method will also sometimes straighten saws where the back is a sawn kerf and the plate is glued into it, but it doesn’t always work.
Paul’s method won’t work at all with the second type of brass back.
- This reply was modified 6 years ago by Larry Geib.
Watching these, I feel nothing is beyond recovery, yet it wasn’t too long ago that the ‘dark art’ of saw-sharpening, setting, & straightening, was all but lost – with our only option being a new saw!
I used to take my dad’s saws to the Hardware Shop for the “Saw Doctor” to sharpen them. That was a 7-day turnaround.3 April 2018 at 4:24 pm #516867I used to take my dad’s saws to the Hardware Shop for the “Saw Doctor” to sharpen them. That was a 7-day turnaround.
The first company I worked for as a carpenter had a fellow come ‘round to the crews with paychecks on Friday afternoon. While he was there you put a saw that needed sharpening on the end of a broom handle he carried and he sharpened it. A half hour later you got back your sharp saw.
Nobody ever worked with a dull saw.
- This reply was modified 6 years ago by Larry Geib.
7 April 2018 at 12:40 am #519453Thanks guys!
Great info. I was able to remove a the very slight gradual curve which was present.
However now there remains a very slight kink halfway along the teeth. very slight, almost imperceptible except in bight light . Im loath to try and fix it with a hammer, being sprung steel and all id probably do more damage.
I found some guys on the net saying you can remove the handle, clamp some heavy straight steel to either side of the saw plate, just below the teeth so not to get the straight edge hung up on the tooth set and put it in a screaming hot oven for a while then let it slowly cool. although id probably have to remove the brass back? never done that before… might be headed down a long bumpy road.cheers
7 April 2018 at 6:49 am #519557I’d leave it alone. Just hone each side with a stone after you set the teeth.
Heating risks ruining the temper and your spring steel will be a soft noodle.
I have had luck taking small kinks out with a hammer and small anvil. LIGHTLY hammer the high side in the region of the kink just below the teeth. If you are leaving marks on the plate it’s too hard.
But again.
if it’s so slight you have to hold it to the light, it’s too small to worry about.
I have a similar problem. There is a small deviation on the teeth side of the blade but not on the spine (as far as I can tell). I’ve whacked the spine over and over with hammers and flat on the bench, but can’t see any difference on the teeth side. Any suggestions?
9 April 2018 at 2:59 am #520592Thanks Larry!
That appears to have worked.
Small taps with a ball hammer against another hammer clamped in the vice.Austin, have you removed the handle? I found it easier to deliver the correct blow in the correct place with the handle removed. Then the light rapping with the hammer did the trick.
Thanks for the help guys!
9 April 2018 at 7:20 am #520675Congrats. No yo have a larger selection of old saws to choose from that most people will pass up.
9 April 2018 at 3:32 pm #520881Austin, sometimes the saw plate is seated all the way into the back, so hitting it doesn’t make much difference. In that instance, the best thing to do is to put the saw plate in the vise with the back sitting just above the vise jaws, and use something such as a flat headed screwdriver to very gently lever the back up a little all along the length of the back from both sides. You should be able to get the plate to move out by about 1/4″ without too much effort.
9 May 2018 at 8:02 am #541695‘Old Arthur’ would hold the saw teeth up and whack the back on the bench trying to hit all along the back, usually pulled them out straight with one blow.
9 May 2018 at 12:46 pm #541783You will most probably need to whack the back after pulling the plate out, as it will probably result in a plate that isn’t straight.
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