Saw sharpening and setting.

[Roxie]

A question to you learned folk.

I have a tenon saw (my fathers) that needed a bit of TLC. I re-cut the teeth, as per Paul Sellers, and proceeded to set them only to find that several teeth broke off during the process, why? I was using an Eclipse saw set, at the correct TPI and, as far as I could tell, using the same pressure throughout.
Any help appreciated.
John

 

[Jacob]

You may have been setting them the wrong way i.e. bending them right over opposite to how they were.
More likely you need a finer setting on the saw set - if you are trying to bend too much of the tooth it starts to tear in the gullet.
If you've just broken a few teeth I wouldn't worry about it too much - the saw will still be usable and the teeth get filed down in time.

 

[Cheshirechappie]

The numbers on the anvil of Eclipse 77 and similar sawsets don't relate to teeth per inch. Indeed, I don't know what they do relate to, if anything. It's best to ignore them completely.

The best bet is to set the teeth as the lowest setting of the anvil possible, given that on a tenon saw they'll be quite small teeth, and try the saw. If it binds excessively, add just a little more set, and try again. You really don't need much set at all - somewhat less than half the blade thickness on each side. The kerf the saw makes should be about half as wide again as the blade is thick, or maybe a little more for use on wettish softwoods, but no more than that.

 

[Sheffield Tony]

Eclipse 77's vary quite a lot. The width of the pin in particular. I've got 3 (for 50p each !), one of which is quite fine and good for small saws, the other two are too big.

 

[Racers]

The saw plate has probably got work hardened over time and made the teeth brittle, I have had the same problem my self.
I don't know it tempering the blade would work, its a big area to heat evenly.
It should still work even with broken teeth.

Pete

 

[deema]

I think that the most common faults have been outlined.

I would strip all of the teeth completely off nd try again, you can also choose what sort of saw you want which is a bonus. If you still get the same problem, chances are that the steel is work hardended and you need to replace the blade......or sell it!

I did a thread in how to sharpen a saw / strip off the teeth and atsrt again which might be of interest.
hand-saw-restoration-and-re-teething-of-a-99p-saw-t98494.html

 

[Jacob]

......
I would strip all of the teeth completely off nd try again, you can also choose what sort of saw you want which is a bonus.

Only if you are an obsessive tool enthusiast with no time for woodwork!

If you still get the same problem, chances are that the steel is work hardended and you need to replace the blade......or sell it!.....l

I doubt the idea about "work hardening" - having had the use of some very hard worked saws over the years.
If you do replace the blade you might as well replace the handle as well. i.e. just buy another saw. :lol:

 

[Racers]

For Jacob

https://en.wikipedia.org/wiki/Work_hardening

Pete

 

[Jacob]

For Jacob

https://en.wikipedia.org/wiki/Work_hardening

Pete

Yes thankyou Pete I know what work hardening is but I doubt you'd get anything like it in a hand saw blade.
But that's what it feel like if you snap off teeth. I've done it myself on an old saw and they snapped off easily like toffee. My first thought was work-hardening or rust. Then I realised the saw set was set too far for the tooth size, and I haven't done it since!

 

[Bod]

Had a small tenon saw, sharpened the teeth, well and truly blunted the file in the process!
Teeth just snapped off when trying to put an small even set on. The blade was just too hard, kept the screws, scrapped the rest.
It was just an old low quality saw, possibly ok when new, but not maintainable.
Keep yours for sentimental reasons, not use.

Bod

 

[bugbear]

From a Henry Disston pamphlet:

We have frequent complaints about hard saws, but they are not as hard as we would make them if we dared; but we shall never be able to introduce a harder saw until the mechanic is educated to a more correct method of setting it. As a rule saws are set more than is necessary, and if more attention was paid to keeping points of the teeth well sharpened, any well-made saw would run with very little set, and there would be fewer broken ones.

BugBear

 

[Jacob]

From a Henry Disston pamphlet:

We have frequent complaints about hard saws, but they are not as hard as we would make them if we dared; but we shall never be able to introduce a harder saw until the mechanic is educated to a more correct method of setting it. As a rule saws are set more than is necessary, and if more attention was paid to keeping points of the teeth well sharpened, any well-made saw would run with very little set, and there would be fewer broken ones.

BugBear

Yes that's it as I said above - if you set them too much it's as if they are brittle and they start snapping off. The tooth should only be bent from some point well above the bottom of the gullet.

 

[pedder]

The saw doesn't happen to have hardened teeth?

 

[worn thumbs]

This thread resonates with me.I have a couple of Eclipse saw sets and the numbers bear no relationship to an appropriate amount of set.I have had the experience of snapping some teeth on a very second hand tenon saw and it seemed to be the case that the saw had so totally lost any trace of set that I must have been setting them in the opposite direction to their original inclination.The good news was that once set,they worked quite well and the saw gave several years service before I sold it to somebody who needed a saw for all of £2.Which happened to be the amount I had just paid for a rather nicer,but blunt Spear & Jackson tenon saw at a car boot sale and which sharpened nicely.

 

[Phil Pascoe]

The saw doesn't happen to have hardened teeth?

Probably not - he said he re cut them.

 

[Bod]

The saw doesn't happen to have hardened teeth?

Mine definitely didn't, it was far to old!

Bod