Sharpening a circular sawmill blade

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Hand sharpeners vs. automatic sharpeners--their pros and cons. July 3, 2001

For a year I've run a Foley-Belsaw with a 48" saw. I've always sharpened by hand with a flat file. Is it worth investing in a good sharpener? Is it possible to over-sharpen and waste more of the tooth, using a sharpener?

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I have never used a flat file to manually sharpen. For 18 years I used a circular file that you cranked. It was very accurate, cranking each tooth the same amount of times. However, the files were expensive. About 2 years ago at a sawmill auction, I bought a Jockey saw grinder. I can sharpen my 54" saw in about 10 minutes. Had I known a saw could be sharpened that easy and fast, I would have gotten one a long time ago.

You do have to be careful not to grind too much or too fast and heat the tooth. I prefer to just tap the grinding wheel 2 or 3 times against the tooth lightly. You will replace the teeth a little more often, but the time saved sharpening will outweigh the cost of the teeth.

Meadows Mill in North Wilkesboro, NC sells a hand crank filer for circular saws. I use one on my edger. When I had a circular mill, I used one on the headsaw and really liked it. When used properly it will keep your teeth sharpened at the correct angles.

A jockey is probably the best way to go. You shouldn't have any problems learning to use a grinder as long as you take your time and be careful while you're getting the hang of it. Keep in mind, the rock you use on a saw grinder doesn't take a rough, deep cut like a bench grinder rock (relatively speaking). Just as a rasp removes more wood per stroke than a file, but a file gives a finer finish.

As with any tool that needs sharpening, file light and often. Big showers of sparks don't accomplish much more than the destruction of your saws.

I like to hand file. I can do it quicker than with a sharpener. The automatics do keep the angle well, but have always been rough on teeth, no matter how light the touch.

There is a Dexter file guide for hand files. It uses a 10" file, and it will give you the correct angle and is fast. You can get a diamond file for chrome and carbide. I've used one and it works well.

I believe the circular files are too expensive and don't last as long.

The least expensive and most accurate is the Andrus hand filer. A little tricky to set up, but definitely the best for most applications. I currently use jockeys for both my head saw and vertical edger. While faster and easier, it can be damaging to your teeth. Very easy to overheat and even easier to lose the proper angle. I keep a small angle gauge to constantly monitor this. Keeping your teeth smooth and sharp is the key to performance and bit life. Light and frequent sharpening is ideal.

Where do you get a Dexter file guide?

I bought my file guide from the Millworks of New England in Orange, MA.

The Dexter is made by Sawmill Tool & Service Co. in Lyndonvill, VT.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
I don't like the jockey grinder. I taught myself how to hand file with both hands and I can now accuratly file 124 teeth in 20 min. There's no substitute for looking at each tooth closely to get a feel for what's going on with your saw.