Crosscut saw sharpening - tracking what teeth you've filed

[baldpate]

Hi all,

today I took my first steps into saw sharpening. The unfortunate object of my attentions was a small (8" blade) S&J backsaw : 13tpi, crosscut, owned since new in the 90's and never sharpened. I only realised how blunt it was when I recently bought a 14" tenon saw off EBay, which the seller said had been freshly sharpened - the difference was very noticeable. This prompted me to read up on sharpening, make myself a very simple saw vice (alla Tom Nielsen) & some elementary jigs for keeping constant rake & fleam, and to have a go!

I was pleased with the result - significantly sharper than before, though I'm sure quite imperfect by expert standards. The thing I had most trouble with, oddly enough, was keeping track of which was the next gullet to file. This was particularly so on the second pass, from the other side of the blade : unlike the first pass, where you are working forward into totally vigin metal, on the second pass you are trying to pick your way between already filed gullets (so a lot of shiny, freshly-filed metal to deceive the eye).

It doesn't help that my eyesight isn't what it was, and my workshop has poor lighting (it's in the loft of my house, with a single velux window over the bench, so I rely heavily on artificial lighting). I tried using some 2x reading glasses, which helped a bit but didn't really solve the problem.

Has anybody any tips for overcoming this, or is it just something which will come with practice?

Thanks

Chris

 

[andy king]

Hi Chris,

I've always dabbed a marker pen on the gullets. As you make a pass with the file it's removed, leaving it easy to spot where you've been with the file.

Cheers,
Andy

 

[Chrispy]

Hi Chris

The last time i sharpened a saw I ran a smoky candle flame along the teeth to blacken them first then it's much clearer to see where you've been.

I to must get a new file and have a sharpen up.

 

[Fat ferret]

Mark the teeth with candle smoke if you need too but natural light makes it much easier. Any chance of dragging your bench outside?

 

[bugbear]

Hi all,

today I took my first steps into saw sharpening. The unfortunate object of my attentions was a small (8" blade) S&J backsaw : 13tpi, crosscut, owned since new in the 90's and never sharpened. I only realised how blunt it was when I recently bought a 14" tenon saw off EBay, which the seller said had been freshly sharpened - the difference was very noticeable. This prompted me to read up on sharpening, make myself a very simple saw vice (alla Tom Nielsen) & some elementary jigs for keeping constant rake & fleam, and to have a go!

I was pleased with the result - significantly sharper than before, though I'm sure quite imperfect by expert standards. The thing I had most trouble with, oddly enough, was keeping track of which was the next gullet to file. This was particularly so on the second pass, from the other side of the blade : unlike the first pass, where you are working forward into totally vigin metal, on the second pass you are trying to pick your way between already filed gullets (so a lot of shiny, freshly-filed metal to deceive the eye).

It doesn't help that my eyesight isn't what it was, and my workshop has poor lighting (it's in the loft of my house, with a single velux window over the bench, so I rely heavily on artificial lighting). I tried using some 2x reading glasses, which helped a bit but didn't really solve the problem.

Has anybody any tips for overcoming this, or is it just something which will come with practice?

Thanks

Chris

I've probably done around 15-25 saw sharpenings, which I guess puts me at "practised beginner". On the plus side, I'm still fairly conscious of (and can describe) what I do, whereas someone who does 20 saws a day probably hasn't thought about technique in years!

If that was your first saw-sharpening, you've done extremely well if you didn't cock it up completely. =D> =D> 13 TPI crosscut is HARD.

On your question; "where have I been", there are two solutions, depending on wether you're doing touch up sharpening or a "full job".

If you doing touch up sharpening, you simply give each gullet the same amount of filing, by keeping the strokes and pressure even, and counting strokes. If you're doing this, some kind of marking (as others have mentioned) is useful, although you may be able to tell fresh metal from old metal by colour/texture if you use magnification (or Elfe-like eyesight).

If you're doing a "full job", the answer is jointing/topping. To file good teeth, you need to be in control, and that means seeing what you're doing. Jointing (not too much!) creates flats on the top of the teeth, which are quite easy to see (given the right light and visual aids). Filing of each gullet is complete when the flat juu...uust disappears. When this happens all the teeth tips can only be perfectly in line.

If you're doing this, and looking carefully enough at the flats to control the filing pressure, number of strokes, and side force, marking is redundant, especially since you may well visit gullets more than once as you even up the tooth spacing.

BugBear

 

[MIGNAL]

Bench magnifier or visor will help. I use a marker pen, although engineers blue might be better.

 

[pedder]

You certainly can use any colour to mark the filed gullets. Some of the really good guys do that.

I try to get there without and had success up to 18 tpi croscut. (Can do that only just after several hours of well sleeping.)

The trick is to have goo light. I think one neon tube along the saw vise is the best. I need to positon the vise that only the little flats reflect to my eyes. Than I can see easily wich gullet is file. BTW, filing a wrong gullet causes aggressive noise wich tells me something is wrong.

I'm writiing I the whole time because I know that eye power is different and doesn't get stronger when you get older. Nonetheless, I think it is the best to try saw sharpening without any optical help other then the the glasses your have to were while reading. All these magnifieres disturb the 3D viewing and you soon need jigs to tell you if you are perpendicular to the blade and so on.

The distance frome my eye to the vise is about 30cm.

Cheers
Pedder

 

[matthewwh]

The only thing I can add is that I keep my head at a compound 45 degrees to the toothline (ie 45 degrees above and 45 degrees behind perpendicular. From this angle the set is more obvious, so the tooth you want to file the front of looks a bit longer than the ones either side of it.

It still takes a good deal of concentration so it pays to stop for a cuppa and a few minutes looking at something far away between sides (kinda like stretching for your eye muscles).

I did five 15tpi crosscuts yesterday, do a bit, do something else, come back and do a bit more. If I had tried to do them all one after another I would have given myself a migrane and probably made a pigs ear of them too.

 

[baldpate]

Thanks for all the valuable advice.

I think the first thing to try is marking the teeth before I start. I saw it done in the Tom Neilsen video, but unfortunately the only marker to hand when I started had dried up, so I went ahead without. So many of you have suggested it, though, that I shall make sure I have a fresh one available next time.

The other point that comes across is the importance of good lighting. I'll try some higher power close-up lighting next time.
[@ Fat ferret who asked "Any chance of dragging your bench outside?" - not a chance, I'm afraid: it must weigh about 50kg and it's in my loft workshop ]

I'm encouraged by the fact that even the experts don't suggest it's easy! [@Mathew - PS: your videos on the subject were very helpful]

Cheers & thanks again to everybody

Chris

 

[pedder]

The other point that comes across is the importance of good lighting. I'll try some higher power close-up lighting next time.

This is IMHO the opposite of good light. I need light that shines parallel to show all the flats. I don't need strong reflections but consistent reflections. And again only from the flats. If I go there with a 100w halogen bulp everything shines not only the flats but every singel bevel.

What I'm looking for is:

There are desktop lamps with a neon tube:

pictures taken from the most detailed sharpening instruction by Friedrich Kollenrott (in German) http://www.woodworking.de/schaerfprojek ... rfen1.html

Cheers
Pedder

 

[AndyT]

I did five 15tpi crosscuts yesterday, do a bit, do something else, come back and do a bit more.

Matthew, I hope you don't mind my asking, but do you personally sharpen the saws you sell through your business, or do you have the biggest collection of all of us?

 

[matthewwh]

Hi Andy,

Usually we don't, although we do provide instructions and sell the necessary files for the job and offer a sharpening service for those that prefer not to sharpen their saws themselves. If it's beyond my skills (retoothing to a different pitch for example) I send them up to Sheffield.

This was a box that arrived rip filed rather than crosscut, it was quicker to redo them than to send them back. If anyone wants their new saw tuned I suppose they could order a sharpening at the same time although the new ones cut pretty well straight from the box.

If I'm honest I'd much rather help people learn to do it themselves, it's no harder than sharpening a plane or a chisel once you have done it a few times and if things do go really pear shaped I'm happy to sort them out.

 

[DTR]

pictures taken from the most detailed sharpening instruction by Friedrich Kollenrott (in German) http://www.woodworking.de/schaerfprojek ... rfen1.html

That's a nifty looking jig that the good gentleman is using in this photo:

Which brings me to this... Everything I've read on crosscut sharpening says to sharpen the teeth set towards you, ie filing towards the handle. Mr Kollenrott appears to be doing the opposite... If only I could read german.

 

[bugbear]

Which brings me to this... Everything I've read on crosscut sharpening says to sharpen the teeth set towards you, ie filing towards the handle.

You need to read more (or not...). That's one of the more hotly debated aspects, along with the best sequence for topping, filing, setting.

BugBear

 

[DTR]

You need to read more (or not...). That's one of the more hotly debated aspects, along with the best sequence for topping, filing, setting.

BugBear

Fair enough, I suspected as much. Thanks

 

[Benchwayze]

ISTR the old timers used soot from a candle to 'black' the gullets prior to sharpening.

It might have been in a dream though. When I was a lot younger I use to eat, sleep and dream woodwork. Now I just sleep, and the dreams are of a different sort... :mrgreen:

John

 

[pedder]

pictures taken from the most detailed sharpening instruction by Friedrich Kollenrott (in German) http://www.woodworking.de/schaerfprojek ... rfen1.html

That's a nifty looking jig that the good gentleman is using in this photo:

Which brings me to this... Everything I've read on crosscut sharpening says to sharpen the teeth set towards you, ie filing towards the handle. Mr Kollenrott appears to be doing the opposite... If only I could read german.

Yes, Friedrich thinks he has to use an optivisor and because of that he hast to use jigs of all kinds. Do you believe he is the major warrior for freehand sharpening chisels and plane blades?

I file all teeth from on side. So do 3/4 of all regular sharpener I know.

Cheers
Pedder