There. I said it. I file saws the wrong way. I feel better.
You must be wondering what the heck I’m talking about. Let me catch you up…
The old texts on saw filing are clear. They indicate you should never file a saw only from one side. They all unanimously say that you should file every other tooth and then flip the saw around in the vise and file the teeth you skipped from the other side. I don’t do that. I file a saw all from the same side. Why? Because when I was learning to file saws, that was the way that made sense to me. And I’m certainly not the only one…many saw makers and saw filers today file all from one side. I can’t honestly remember what possessed me to start filing this way…it certainly wasn’t my idea.
As I’m writing an article for Popular Woodworking Magazine on saw sharpening, I find myself thinking more and more about this topic (thanks to the good-nature antagonizing of my friend Carl).
But what are the reasons to NOT file a saw that way? I have heard a few…
1) Filing from one side of the saw dulls the file faster because you have to file into the teeth leaning towards you, which causes more wear on the file teeth.
I think this is a silly point. The gullet edge of the file is what wears out first and destroys a file. The extra wear to the face edges is completely irrelevant…they stay intact long after the file is useless regardless of how you file teeth.
2) Filing from one side of a saw alone puts all of the filing burrs on the opposite side of the saw teeth and will cause the cut to steer to that side when the saw is used.
I have filed hundreds of saws. The only case where I have found the above argument to be true is in dovetail saws and similar saws spaced 14 points and finer. These saws have fine teeth that can be affected by the burr, but an extra side jointing pass or two on the burr side of the tooth is a simple remedy. The burr created on teeth coarser than 14 points are unaffected…I’ve found that they are large enough to overcome any discrepancy.
3) You cannot create saw teeth with independently shaped back bevels (sloped gullets) filing from one side of the saw.
I would say this is mostly true. But for 95% of woodworkers, I don’t think it makes any difference filing independent back bevels on your teeth. For most work, the benefit is negligible. Can you gain a small advantage in your work with independently shaped back bevels? Sure. But to me, its like the difference between a Corvette and a Ferrari. Is it really worth it? I don’t think so.
This whole argument may be like the tails vs. pins first argument with dovetailing: it’s simply a matter of preference and opinion. There is more than one way to skin a cat. And I love skinning cats.
But as much as I like torturing small domestic pets, I like free thinking all the more. Because I am stubborn, naive, and foolish, any wisdom I have gained in life has come from making so many mistakes that success was the only option remaining. What drives me in my business and in craft is the hope that I never stop learning, never stop improving and never stop questioning tradition. I would rather be comforted by a small token of marginal truth hard-won through years of trial and error than bask in the glory of unimaginable wealth blindly accepted from a benevolent master.
What the heck does that mean? I like doing it wrong. Wrong feels right to me.