TYZACK Backsaw Heresy?

[paulrbarnard]

Greetings Brothers,

I have recently been in the process of restoring several of my older backsaws.

The one in question here is a generally nice but somewhat neglected TYZACK with a brass back (upper saw in image).

In the process of restoration, I dismantled it, cleaned it up, and reassembled it. As you can see, the saw plate was moderately pitted.

View attachment 181597

In my experience, one can still produce a usable saw despite the pitting. Not ideal, but still cuts wood reasonably well. When I set the teeth, I follow it with some light stoning, which I believe, along with filing, removes any pitting from the cutting tips.

Sadly, when it came time to sharpening and re-setting the teeth, I found that many of the teeth were snapping at the base, despite only a moderate set.

I did a little research, and found that older saw plates sometimes undergo what is termed "crystallization" of the steel, which makes it brittle and prone to cracking.

So, I was left with little choice but to replace the saw plate.

I had on hand spring steel/shim stock in various thicknesses; 0.020 and 0.032 inches. The steel is somewhat hard, but responded to filing without too much difficulty. I used the latter, thicker steel, but will choose the thinner for most future saw plates.
The original saw plate was 0.027 inches thick. I reasoned that the thicker steel would be less prone to deformation on this unusually deep plate.

So, I traced and cut the new saw plate to match the old one, but left the entire depth of the spring steel (6 inches), having seen some saws with this type of exceptionally deep blade, and wondering if it would be useful/practical in the shop. We will see...

View attachment 181598

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So, I assembled the saw, and cut new teeth using a "graph paper" technique I found recommended on YouTube by Bob Rozaieski ().
I pasted the graph paper on the the saw plate and filed the tooth gullets. When I do this again, I will still use the graph paper technique, but start with a fine-toothed hacksaw blade to form the tooth gullets as done by Paul Sellers ().

BTW, all manner of graph paper is to be found on the internet in downloadable *.pdf format. I found graph paper in 4, 8, 10, 12, and 16 TPI. I am sure that more choices are available.

View attachment 181600

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Here, the coarse tooth gullets have been formed with a file:

View attachment 181602

And finally, the teeth were formed and set to a 10 TPI crosscut pattern. I thought this might make a passable carcase saw.

I used a Veritas saw file guide for the first time in this project, but found the fleam protractor scale was off by about 5 degrees*. I contacted Veritas about it, but am still waiting to hear from them.
I also had trouble with the rake angles, and ended-up having to file the teeth five times until I got it right.
Has anyone else found this problem* with their Veritas saw filing guide?

View attachment 181605

Is it heretical to replace the saw plate?

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Turns out I’ve got a steel backed one that looks pretty much identical. This was my great grandfathers. It’s in my user rack.

This is my rack. They all see a fair bit of use

 

[spanner48]

Spanner48, thanks for explaining, I only asked re a possible business opportunity I can foresee coming out of this.
Re what your doing, I suppose I don't need to tell/remind you about engineering blue, as all the work involved would respond to it's use, if that is you can get a whole saw plate on dismantling the old one?

I'm not quite sure what you're asking.

Yes, I did use to use engineering blue, but only when scraping white metal {Babbit] bearing shells to fit a crank- or camshaft on really old [pre-Vandervell] engines.

As for using the old plate as a marker for the replacement: that's fine for the sawscrews ; but not for the teeth. Most old saws have seriously distorted toothlines, caused by repeated faulty sharpening by previous owners. Correcting that can be a real pain: either a complete jointing, to remove the whole toothline, and start over. Or a half-jointing; filing off the tops of the higher teeth until the lowest tooth is just being touched. Then recut filing the gullets to the same level, pushing sideways on each tooth differently, to "shift" each one forward or back, to even out the pitch.

And that's just dealing with uneven toothing. But there will also almost always be hollow toothing, where the original factory breasting has been reversed to a hollow over time, as the sawyer repeatedly concentrates his sharpening in the middle of the saw, where the wear is at its greatest. Rather than giving each tooth from end to end the same amount of sharpening.

In each case, if it's not too bad, it's worth going down the "Half-joint, then correct" route; otherwise it's a complete jointing, and a new toothline marked out and cut.

 

[bentontool]

Turns out I’ve got a steel backed one that looks pretty much identical. This was my great grandfathers. It’s in my user rack.
View attachment 181814
This is my rack. They all see a fair bit of use

View attachment 181816

Nice rack! I zoomed-in... looks like all the teeth on the racked saws are sharp!
Being an emigrant, and having both my grandfathers die when I was young, I never inherited any of their tools. I miss that pride in familial ownership that comes to many.
Best wishes!

 

[Jacob]

Hello Jacob,
Thanks for your reply. I am curious to know how you adjusted the setter to achieve the desired results. Did you reduce the amount of set? I tried simply reducing the set but they still snapped. Did you have to modify the anvil on the setter?

Basically less set and also filed the plunger to an edge rather than a flat face so it would go between smaller teeth.
My favourite discovery about old saws (if not damaged) was how little you need to do to get them working nicely. Sharpen, brush off loose rust, brush on thinned linseed oil to the whole saw, wood and metal, when it's dried off enough use the saw. They polish themselves up with use, very nicely quite quickly, low friction even though still rusty brown colour.
https://www.ukworkshop.co.uk/threads/first-saw-restoration.129795/#post-1458516
PS found a link https://paulsellers.com/2014/03/refining-sawsets/

 

[paulrbarnard]

Nice rack! I zoomed-in... looks like all the teeth on the racked saws are sharp!
Being an emigrant, and having both my grandfathers die when I was young, I never inherited any of their tools. I miss that pride in familial ownership that comes to many.
Best wishes!

Yes all in use. I’ve sharpened my own saws for the last 40 years. There is a selection of rip and cross cut of various tpi in the rack.
The shiney tennon saw in the middle is a new addition recently purchased from here. The two on the right are also modern LN saws but I’ve had those for 20 years. The rest are all either grandfather or great grandfather hand me downs. They were both joiners. My great great grandfather was too but he had the same name as my great grandfather so we aren’t sure if any of the tools came from him. So many of the family tools didn’t make it to me. I was living in Canada when my grandfather died and my grandmother gave the bulk of the tools away to a clearance company. I often think back to being in his workshop with the rows of moulding planes and bench planes lined up on shelves. They all went…

 

[bentontool]

Basically less set and also filed the plunger to an edge rather than a flat face so it would go between smaller teeth.
My favourite discovery about old saws (if not damaged) was how little you need to do to get them working nicely. Sharpen, brush off loose rust, brush on thinned linseed oil to the whole saw, wood and metal, when it's dried off enough use the saw. They polish themselves up with use, very nicely quite quickly, low friction even though still rusty brown colour.
https://www.ukworkshop.co.uk/threads/first-saw-restoration.129795/#post-1458516
PS found a link https://paulsellers.com/2014/03/refining-sawsets/

Thanks Jacob. I have a second saw set that I ground the "hammer" (I was incorrectly referring to the hammer as the "anvil" prior, sorry) to a finer point to use on one of my dovetail saws with 20 TPI (still a very difficult saw to sharpen and set!). I will try that on the Tyzack plate to see if I can successfully set the teeth. Thanks for the tip and the links!

 

[bentontool]

Yes all in use. I’ve sharpened my own saws for the last 40 years. There is a selection of rip and cross cut of various tpi in the rack.
The shiney tennon saw in the middle is a new addition recently purchased from here. The two on the right are also modern LN saws but I’ve had those for 20 years. The rest are all either grandfather or great grandfather hand me downs. They were both joiners. My great great grandfather was too but he had the same name as my great grandfather so we aren’t sure if any of the tools came from him. So many of the family tools didn’t make it to me. I was living in Canada when my grandfather died and my grandmother gave the bulk of the tools away to a clearance company. I often think back to being in his workshop with the rows of moulding planes and bench planes lined up on shelves. They all went…

Sad... sorry to hear that... truly a great loss.
I am sure it happens often.

 

[Jacob]

Thanks Jacob. I have a second saw set that I ground the "hammer" (I was incorrectly referring to the hammer as the "anvil" prior, sorry) to a finer point to use on one of my dovetail saws with 20 TPI (still a very difficult saw to sharpen and set!). I will try that on the Tyzack plate to see if I can successfully set the teeth. Thanks for the tip and the links!

I gave up trying to set anything smaller than about 12 tpi cos I can't see them! Instead I black felt-tip the teeth and file alternately down one side then the other, having checked with a loupe to see which way the set goes and which gullet to start in. Then you do it by feel, you can see where you've been and the file leaves enough set for most purposes. Thing is to do it fast on one op down each side so that you are removing roughly equal amounts at roughly the same angle. Trying to see what you are doing tooth by tooth even with a lens just makes it a struggle.

 

[bentontool]

I gave up trying to set anything smaller than about 12 tpi cos I can't see them! Instead I black felt-tip the teeth and file alternately down one side then the other, having checked with a loupe to see which way the set goes and which gullet to start in. Then you do it by feel, you can see where you've been and the file leaves enough set for most purposes. Thing is to do it fast on one op down each side so that you are removing roughly equal amounts at roughly the same angle. Trying to see what you are doing tooth by tooth even with a lens just makes it a struggle.

Yes, I have the same trouble, much worse since my cataract surgeries. I now can't see anything within six feet in focus, so I bought some magnifying headsets, but they are difficult to use at best. You have to get really close to the teeth for them to be in focus. If you deviate from the "sweet spot" (too close or too far), it all gets out of focus again.
Oh well, getting old "ain't for sissies", as they say...

 

[spanner48]

Basically less set and also filed the plunger to an edge rather than a flat face so it would go between smaller teeth.
My favourite discovery about old saws (if not damaged) was how little you need to do to get them working nicely. Sharpen, brush off loose rust, brush on thinned linseed oil to the whole saw, wood and metal, when it's dried off enough use the saw. They polish themselves up with use, very nicely quite quickly, low friction even though still rusty brown colour.
https://www.ukworkshop.co.uk/threads/first-saw-restoration.129795/#post-1458516
PS found a link https://paulsellers.com/2014/03/refining-sawsets/

That's the right way for the plate. But totes - if wood - often also need attention: split, cracked, horns broken off, sawscrews loose/missing, etc. But some work will normally make a difference: