Novel tooth form.

[Phil Pascoe]

What do you think of these? Interesting, eh?







The saw is actually quite nice - worth a fiver, I think. I bought it to practice on, but I think it's a bit better than that.





What do you think? It'll be a while before I get to it.

The plate is 410mm long, 92mm - 95mm deep. The maker is "Rockingham".

 

[bugbear]

interesting - 3 nuts on a back saw (unsual), and a flat bottomed handle (which is early, and AKA London pattern IIRC).

Typical case of small errors at each successive filing building up.

That's so bad, I would suggest your best path is to joint the blade until toothless, and make new teeth with the method of your choice; I'd use a paper template.

Reforming existing bad teeth might - just - save more of the plate in some cases, but in this case I doubt it.

BugBear

 

[D_W]

It's like a fireman's schedule, one tooth on, two off. Maybe they work in rotation.

 

[AndyT]

I think it's already been practised on!

According to BSSM, Rockingham is a second quality saw, but Simon Barley has not yet found a definite name of the actual maker. He does say that several makers had premises in Rockingham Street or Lane, including Tyzack, Sons and Turner, who might have made it. (London pattern handles continued in use on second quality saws later than they did on the best saws.)

This could be a nice case to consider in the other thread on restoration - it's a common tool, of no great value to anyone, but could easily be over a century old. It's useless as it is but could be put back into use relatively easily.

 

[Racers]

I would file it flat and start again.
Last one I did I gradually deepened the teeth keeping an eve on the flats to make sure they where equal, it took about 8 passes to get to full depth but I had nice even teeth.

Pete

 

[Phil Pascoe]

It's worthwhile I think - there's plenty of depth there, it's straight and there is little rust, it's mainly staining from being packed away in contact with something that's marked it.

 

[lurker]

As Pete suggests.

But if you are poor hand skills like me. I'd use a powered hacksaw blade of approriate TPI and clamp it level. Just straight file across until you have made an impression of each tooth, then remove and sharpen as usual.

Might make a good rip which I find more useful than a, harder to sharpen, cross cut.

 

[Phil Pascoe]

This'll be a rip. There are another three in queueing behind it ...

 

[Cheshirechappie]

That's actually quite a nice find - 410mm/16" backsaws are not all that common. It'll make a cracking 'proper' tenon saw.

The state of the teeth isn't that unusual for a secondhand saw. Another common fault is that someone sharpens the teeth in the middle of the blade more than at the ends, resulting in a 'hollow' toothline - I've seen one or two where the hollow is about 1/4" or more. Jointing up one of those can take quite a bit of filing.

In general, it takes patience to make a decent saw out of such a wreck, but it's good practice, and usually worth it if the blade is straight - normal saw sharpening is a doddle after doing one of those.

 

[Phil Pascoe]

This one as luck would have it is straight as a die.

 

[Jacob]

.... Another common fault is that someone sharpens the teeth in the middle of the blade more than at the ends, resulting in a 'hollow' toothline - I've seen one or two where the hollow is about 1/4" or more. Jointing up one of those can take quite a bit of filing.......

it's not a "fault" as such it's just that saws get most wear in the middle and subsequent sharpenings make a hollow. Within reason this doesn't affect the saw in use and it's not always essential to straighten it out - in fact best deferred as long as poss to lengthen the life of the saw. Some saws look very irregular if you squint down the length but may sharpen and cut perfectly well.

 

[Cheshirechappie]

.... Another common fault is that someone sharpens the teeth in the middle of the blade more than at the ends, resulting in a 'hollow' toothline - I've seen one or two where the hollow is about 1/4" or more. Jointing up one of those can take quite a bit of filing.......

it's not a "fault" as such it's just that saws get most wear in the middle and subsequent sharpenings make a hollow. Within reason this doesn't affect the saw in use and it's not always essential to straighten it out - in fact best deferred as long as poss to lengthen the life of the saw. Some saws look very irregular if you squint down the length but may sharpen and cut perfectly well.

Why bother with a saw, Jacob? Why not just chop it with an axe? :lol:


'Best' saws have a slightly breasted toothline. Good ones have a straight toothline. Hollow toothlines are considered less than perfect. Sure, it might work - after a fashion - but it's emphatically NOT best practice.

 

[Jacob]

... Hollow toothlines are considered less than perfect. ...

Hollow toothlines are merely a sign of use, are neither perfect nor faulty and up to a point will make no difference to the use of the saw.
Who makes up all this "best practice" gibberish?

 

[D_W]

.... Another common fault is that someone sharpens the teeth in the middle of the blade more than at the ends, resulting in a 'hollow' toothline - I've seen one or two where the hollow is about 1/4" or more. Jointing up one of those can take quite a bit of filing.......

it's not a "fault" as such it's just that saws get most wear in the middle and subsequent sharpenings make a hollow. Within reason this doesn't affect the saw in use and it's not always essential to straighten it out - in fact best deferred as long as poss to lengthen the life of the saw. Some saws look very irregular if you squint down the length but may sharpen and cut perfectly well.

It's a consequence of that, but a conscious user can maintain a saw pretty well without jointing just by working the toe and heel hard enough to make sure that it stays in line with the rest of the saw. To the extent that heel teeth never get in a cut, I sometimes file the last couple mostly off so as to avoid sharpening them every time.

If someone feels the need to joint, if they have a moderate touch on a saw, it's something that can be done only every half dozen or dozen sharpenings or so. Heavy jointing at each sharpening (which has nothing to do with this thread) wastes teeth when a saw is only dull but without misshapen teeth.

 

[Jacob]

Yes. Defer topping as long as you can.
I tend to sharpen blind by feel - just going up one side and then the other as regularly as possible, without trying to impose any corrections, until the next (infrequent) topping.

 

[Cheshirechappie]

Who makes up all this "best practice" gibberish?

Good craftsmen who take a bit of pride in their tools, so that they work as well as they can.

 

[Jacob]

Who makes up all this "best practice" gibberish?

Good craftsmen who take a bit of pride in their tools, so that they work as well as they can.

Tool fiddlers and polishers more like!

 

[Cheshirechappie]

Keeping a saw tooth line straight (or slightly breasted) is nothing to do with 'tool fiddling or polishing'. It's just good practice. Allowing a saw tooth line to become hollow is not good practice.

How would someone cut tenon cheeks or shoulders to the line all across their width using a saw with a hollow tooth line, for example?

 

[Jelly]

interesting - 3 nuts on a back saw (unsual), and a flat bottomed handle (which is early, and AKA London pattern IIRC).

As a big Tyzack fan, I find this less unusual... Most of their Steel-Backed backsaws that I've seen have 3 nuts...

Which leads nicely to:

Tyzack, Sons and Turner, who might have made it. (London pattern handles continued in use on second quality saws later than they did on the best saws.)

Indeed, The first of the three works making tools set up by the business (then trading as William Tyzack and Sons) was at Rockingham Street, which closed in 1881 to allow further investment at the Little London Works, at Heeley, near their rolling mill and the scythe works & crucible furnaces at Abbeydale just a way up the River Sheaf.

 

[Jacob]

Keeping a saw tooth line straight (or slightly breasted) is nothing to do with 'tool fiddling or polishing'. It's just good practice. Allowing a saw tooth line to become hollow is not good practice.

Good practice is to sharpen a little and often but only to "top" intermittently

How would someone cut tenon cheeks or shoulders to the line all across their width using a saw with a hollow tooth line, for example?

Within reason, in normal use, this is no problem. Practice and logic don't always coincide!