How not to sharpen a tenon saw!

[iajon69]

After a conversation with someone the other week about the condition of some of the saws that I sharpen, just had this tenon saw in - the owner has had a go at sharpening it himself and is not quite sure how he managed to get it to this state but apparently it didn’t take too long!

Looks as if he’s been attempting to design a new tooth shape

This is not the worst saw that I've seen but this one of the rare occasions that there was a digital camera in work so I could take a few pictures.

First time that I've uploaded pictures so hopefully they will work - thanks to Alf for the guide

Hopefully by clicking on an image you will get a bigger picture to really see how bad the teeth are.

Cheers

Ian

 

[WellsWood]

:shock: :shock: :shock: :shock: :shock: :?:

 

[tnimble]

If you would only post a close-up without any comment I would think it is abstract miniature of a mountain.

What was he trying to do? :shock:

 

[mr]

At least they're a consistent (ish) shape.
Cheers Mike

 

[MIGNAL]

Hybrid design of Japanese and western saw tooth geometry, sort of.

 

[ike]

Coco Cola has a similar effect on teeth. :lol:

 

[Dave S]

I've never sharpened a saw in my life, but I would hope it wouldn't take that many teeth to realise I was messing it up!!!

Dave

 

[JFC]

Ok but can you just fix it and send me my saw back please :lol:

 

[Woodmagnet]

Even a Toblerone would cut better than that. :lol:

 

[Lord Nibbo]

From the state of those teeth I'm glad he's not my dentist :lol: :wink:

 

[iajon69]

Thought that you might want to see the same saw 20 minutes later.

Wasn’t too bad to do – this is where the re-toother makes life a lot easier!
Once it was re-toothed just a case of setting and sharpening and back to a useable condition

Ian

 

[George_N]

Nice job Ian. Would you like to tell us more about the re-toother? I've never attempted to sharpen a saw and I only very vaguely remember what I was taught in school woodwork class 35 years ago. I know that there are a few threads about saw sharpening on this forum and also some external links but I haven't heard of a re-toother...very educational this site.

 

[iajon69]

Would you like to tell us more about the re-toother? I've never attempted to sharpen a saw and I only very vaguely remember what I was taught in school woodwork class 35 years ago. I know that there are a few threads about saw sharpening on this forum and also some external links but I haven't heard of a re-toother...very educational this site.

Hi George, the re-toother is an old Foley machine which has a punch and die that stamps out the teeth in a nice uniform pattern. The saw goes onto a carrier that is fed through the machine via a ratchet bar and the ratchet bars determin the tooth pitch that is punched out.

It's a great machine for putting new teeth in tenon and handsaws and in the past we've even used it to make our own saws - we had some saw handles and some really goood quality Swedish steel from a wide bandsaw which turned into about 6 handsaws.

Once the new teeth have been punched into the saw then sharpening is pretty straight forward as it's a lot easier to sharpen the saw when the teeth are all even.

Here's a picture of the machine but it doesn't really show how it works though!

Ian

 

[George_N]

Thanks for that Ian, very informative. Do you have to grind the old teeth off before cutting the new ones, and if so does that affect the temper of the steel?

 

[iajon69]

Thanks for that Ian, very informative. Do you have to grind the old teeth off before cutting the new ones, and if so does that affect the temper of the steel?

George, there's no need to grind the teeth off - there's a guide to make sure that the saws are re-cut level and there's no effect on the temper. Occasionally some saws are so badly damaged that I have to put a little tension in them and that's done with either a special hammer or a rolling bench depending on where the tension is required and the amount required.

The quality of the steel used in the manufacture of the saw is a huge factor in how good the saw will re-cut and sharpen - most of the old saws seem to come up a treat - had one last week from a someone in his late 60's and the saw was his fathers from when he was an apprentice. He was over the moon with the way the saw looked and cut after a re-cut, set and sharpen

If the saws are hard point saws then it's a different story and generally they are not worth even attempting to re-cut.

Ian

 

[newt]

The other alternative is to take a short instruction from Alf. She did this at Phillys bash and I then got to work on 6 old saws that were really rubbish. I cut 3 to a rip form (3 different rake angles 8,6 and 4) and 3 for cross cut at 12 and 15 degrees fleam, I now use 2 of them all the time in preference to my new saws. Paul and Rob had a go with my cross cut and I think were impressed. I have to say that taking a rusty old saw with many teeth missing, de- rusting, jointing, cutting the teeth, sharpening and setting, Then feel it slice through a piece of hard oak almost under gravity, is so so satisfying, really. And if they are worth nothing all you have lost is the cost of the good quality files (essential)that you need for the job.