Dovetail Saw rework - advice wanted

[lurker]

I have a nice set of brass backed ones I've inherited that I've had sharpened.

I now want to go a step further. I have ambitions to be able to fettle saws as well as I can fettle planes - self taught with a bit of help from friends here.

I bought a car boot brass backed saw (its a 60s-70s Spear & Jackson) and tried to resharpen it and made a right pigs ear of it.

My plan now is to use this but totally recut the teeth.
First I thought I'd chop the blade clean (its about 4" deep) and have been looking at making a Gramercy style one.
I can't work out how to chop the blade(profile) - I can get a mate to physically cut it on his works guillotine.

On the Gramercy ones; from the brass back to the teeth:
Is it parallel from front to back? ( I think not - guessing its deeper at the handle than the tip.
What is this measurement (I guess around 2")

Once I've got this straight edge I was planning to use a 18TPI hacksaw blade as a template.

Am I on the right track?

 

[George_N]

I know nothing about saw sharpening beyond what I remember from school woodwork class almost 40 years ago, but I would have thought using a guillotine was a very bad idea. The potential for distorting the blade would be huge. Better to grind the teeth down with a mill file or the like.

 

[lurker]

George

Thanks.
The machine is a big power jobby so I'd support the underside with a large scrap of sheet steel. I think this will minimise distortion.

I wanted to avoid grinding as I dont want to bu**er up the blade temper.

My main concern about this phase of the project is if the blade is fully (all)tempered - anyone got opinions on that?

 

[George_N]

The saw blade shouldn't be too hard to file, after all that's how you will cut the teeth and sharpen them in the future. I'm not talking about power grinding, so there should be no excessive heat produced. Proper saws aren't like the induction hardened "hardpoint" saws, the steel can be worked with a file. I'm sure Bugbear posted a saw sharpening tutorial not so long ago, have a look for that. It is common practice to "joint" a saw blade prior to sharpening, and that is usually done with a flat file.

 

[Joel Moskowitz]

First I thought I'd chop the blade clean (its about 4" deep) and have been looking at making a Gramercy style one.
I can't work out how to chop the blade(profile) - I can get a mate to physically cut it on his works guillotine.

On the Gramercy ones; from the brass back to the teeth:
Is it parallel from front to back? ( I think not - guessing its deeper at the handle than the tip.
What is this measurement (I guess around 2")

The gramercy saw has a 9" blade which is canted for ease of use. Near the handle the blade has a usable cutting depth of only 1.3", and at the toe it's 1.2".

if you want to file it 18 or 19 ppi use a needle file not a saw file - the flats on even a 4" xx will give you too shallow a gullet for much of a stroke.

Joel

 

[Racers]

Hi, Lurker

Just top off the teeth and re-file then top off the teeth and re-file, by the time you are down to the right depth you should have cracked filling :wink:


Pete

 

[Grinding One]

I have a nice set of brass backed ones I've inherited that I've had sharpened.

I now want to go a step further. I have ambitions to be able to fettle saws as well as I can fettle planes - self taught with a bit of help from friends here.

I bought a car boot brass backed saw (its a 60s-70s Spear & Jackson) and tried to resharpen it and made a right pigs ear of it.

My plan now is to use this but totally recut the teeth.
First I thought I'd chop the blade clean (its about 4" deep) and have been looking at making a Gramercy style one.
I can't work out how to chop the blade(profile) - I can get a mate to physically cut it on his works guillotine.

On the Gramercy ones; from the brass back to the teeth:
Is it parallel from front to back? ( I think not - guessing its deeper at the handle than the tip.
What is this measurement (I guess around 2")

Once I've got this straight edge I was planning to use a 18TPI hacksaw blade as a template.

Am I on the right track?

Try this site http://www.wkFineTools.com/

 

[Racers]

Hi, Lurker

I just filled flat the teeth on that back saw I showed you the other day, and recut it to 14 tpi took about 2 hours with the help of the wifes reading glasses and one of Bugbears templates. It went very well I didn't loose track of the teeth when filling and setting, its now a 14tpi crosscut and works very nicely. Give yours another go, I think you need to keep at it, and it will all come together eventually.

Pete

 

[bugbear]

...nd one of Bugbears templates...

HTH.

BugBear