Saw filing

[Dan McGonigle]

IVe “successfully” set and sharpened a handful of saws, far from perfect, but good enough for me. These have been larger saws, 5-8 tpi, which I suppose are a bit easier than fine saws. One of which was a 12Inch Disston back saw, I filed to rip - was in very bad shape, and it still is, but it cuts adequately. Recently I decided Id finally get around to a beautiful split nut 14inch brass backed saw I bought years ago and have never touched. It’s 11-12 tpi and Im filing it for crosscut. The teeth were all different sizes, no set, and dull. So I first jointed, taking passes with a mill file until 90+% teeth had been contacted. Then I went straight to setting, then filing. Long story short, I messed up. It cuts, but is dull. The teeth look a mess. I realize now that I should have, after jointing, re-defined the teeth by filing with no fleam - then setting - then filing fleam. Im wondering if Im using the right size file because it seems to be a little more aggressive than Id like. Im using a double extra slim 6Inch bahco. And I want to verify something - I read once that when the file is placed in the gullet, the tooth should measure slightly less than half the width of the file. Part of me wants to sent it off for a professional because its such a beautiful saw. But the other part of me is stubborn and determined to learn this better. Any thoughts would be appreciated.

[Tom M King]

Shape the teeth first. Setting will not do any good if the teeth have different spacing. As the point positions change, so will the tops of the teeth.

These might help.

https://www.blackburntools.com/articles/saw-tooth-spacing-templates/index.html

[Jim Koepke]

Don't feel bad Dan. One of my dovetail saws cut adequately but the teeth looked terrible. It took a few passes jointing and a bit of patience to keep a close eye on the teeth while filing. The saw is much better for it now.

One thing to read often for me is Pete Taran's post on saw filing.

It can be found in the library at > http://www.vintagesaws.com/library/library.html

Getting the teeth properly shaped is the first and most important step. After that it isn't as important whether the teeth are sharpened first or set first. Some like the teeth set even for rip saws so they know from which side to file. Others like to file rip teeth all from the same side so setting after filing might be better if that is your procedure.

Here is a saw file chart:

466145

There should also be one in the saw filing instructions in the link above.

jtk

[Kevin Goss]

I'm not sure if this will be helpful but this is a popular youtube video on sharpening western saws that I think has a ton of good information. It's a bit long but definitely at least skip through a bit to get to applicable information for your use. https://www.youtube.com/watch?v=u-_MF2Mnxwc

[Scott Winners]

On a rust bucket restoration I can't personally shape and sharpen teeth in one pass. Once the teeth are all the same height I go through once shaping and then a second time for fleam.

[Dan McGonigle]

Thanks for everyones comments. I have finished re shaping the teeth and filing them. I used 20 degrees of fleam and 15 degrees rake for cross cutting. At least I tried to get close to those angles. Ive made several test cuts and while I’m happy with the speed and ease at which the saw is cutting Im a bit surprised at the finished surface. It is not as smooth as Id expect. The problem is I dont have a frame of reference nor do I know what my expectations should be. I’m not sure what a perfectly tuned 12ppi 14” saw should cut like. Is leaving a rough surface a symptom of something? Like too much set causing movement in the cut? If I were using this saw for joinery, Id have to cut at least 1/32, maybe a touch more to be safe, beyond my mark and shoot down to the line due to how rough this finished surface is. Again, I have a habit of making problems where there is none.

[Jim Koepke]

Dan, do you have a way to measure how much set you have to compare to the thickness of the saw plate just above the teeth?

A 12ppi saw shouldn't leave a real rough cut. Sometimes one over set tooth can leave its own mark.

jtk

[Dan McGonigle]

Yes I’m planning on measuring the saw plate and and set after work. I read that set should measure 20-25% greater than the saw plate. Sound about right?

[Jim Koepke]

Yes I’m planning on measuring the saw plate and and set after work. I read that set should measure 20-25% greater than the saw plate. Sound about right?

If you have a 0.030" saw plate that would be 0.006" of set side to side. That is probably a good starting place. You likely do not want more unless you are cutting a lot of wet wood. If the saw rattles in the cut it probably has too much set. If it binds in deeper cuts it likely needs a bit more.

Saws for different uses have different amounts of set. A dovetail saw, cutting 1/4" to 1" deep, will not need as much set as one cutting long tenons, 1-1/2" to 4" deep. A 26" saw ripping or cross cutting a pine or fir 1X12 may need more set than one cross cutting a 1" by 4/4 piece of dry hardwood. That is why many folks have tills full of saws. At least that is what we tell our wives. :D

jtk

[Dan McGonigle]

I worked it out! The saw plate measured about 0.027” (my micrometer isn’t super accurate, I typically use it to transfer measurements). The set however measured 0.040”. Way too much. I decreased the set using the two hammer method Ive seen Paul Sellers use. Afterwards the set measured .031”. The saw cuts much better now and leaves a finer surface.

[Jim Koepke]

Yay!

jtk

[Tom M King]

Good work!! It always seems like the hardest part about learning to sharpen a saw is overcoming the reluctance to get started.