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