Saw Sharpening

[James C]

I'm learning to sharpen my saws at the moment. I've had a go on my large 7 point rip saw and its cutting reasonably well but not as good as it could be.

I watched a video on sharpening recently which was quite comprehensive and used a technique which I've seen before where a mill file is used to joint the top of the teeth.

I didn't attempt this with my saw as all I have are straight ******* wood files. What kind of mill file should I get do different sizes have different coarseness of teeth?

Thanks

 

[Cheshirechappie]

An 8" smooth mill file will do a very acceptable job.

In fairness, a smooth hand file - almost any size - will do the job; I think 'mill files' are specified because they were made specifically for sharpening larger saws in sawmills, so that's what saw doctors would have had to hand. Smooth cut is best, though a second cut file would do at a pinch.

If the saw is in reasonable fettle (which, by the sounds of it, yours is) only about three or four passes across the top of the toothline will put a 'shiner' on the tips of all teeth. Some people suggest the use of a wooden block or jointing jig to hold the file, and there's nothing wrong with that approach, but I find that a firm grip in both hands is all that's needed. Keep the file horizontal in both planes, and move it slowly but steadily along the toothline, applying moderate downward pressure. Examine after a couple of passes, and continue until all teeth are topped.

If the saw is an internet auction or carboot find that someone has butchered over the years, the tooth heights can be all over the place, and the toothline anything but straight. Use the same approach, but you may need many passes to get things levelled up. If it looks like you're going to file some teeth away altogether, stop jointing and file the affected teeth back to somewhere near new depth, then joint again until the toothline is level. Then file all teeth to proper depth, make one or two jointing passes to even things up, then set and final sharpen. That can take a bit of patience, but it can make a silk purse from a real sow's ear!

 

[James C]

Thanks I will grab myself an 8" Mill File in the near future then.