|Project by bluekingfisher||posted 12-19-2015 09:47 PM||1119 views||5 times favorited||10 comments|
Some time ago I bought an old tenon saw on eBay for a couple of quid, the reason for it being so cheap was it was in a dreadful state. So last weekend I began to try to bring it into a workable condition. Unfortunately I didn’t take any photos but I cleaned the tote and made a couple of small repairs then applied a couple of coats of shellac, followed by two coats of paste wax.
The plate was bowed like a fiddlers elbow and the teeth were filed so poorly but I thought I would give it a go. Anyway, I got them into a reasonable shape but when I set them they began to break off one by one I suspect I must have bent them opposite to the way they had been previously but because they were in such bad shape it was impossible to determine the original set.
So, over the course of the week I decided I would try re toothing the saw to a saw pattern I wanted rather than what was previously on the saw. The original pattern was around 12 PPI. The plate is 14” long so decided on a 10PPI filed for a rip cut.
Filing off the teeth was simple enough. how to establish the layout for the 10ppi was my concern. As always, Google was my friend. I found a pattern on the Norse woodsmith site and printed it off. I used double stick tape to affix it to the plate. The tape in addition to holding the pattern on ensures the file does not skate around when making the initial cut to establish the pattern. Thanks Norse Woodsmith.
I prefer a progressive rake on the teeth, this prevents the teeth from grabbing when a cut is started, not so much an issue on a heavy tenon saws but on small dovetail saws it can be a pain as precise cuts are necessary. The first 10 teeth are filed with the lead edge 15 degrees off vertical. The next 10 are cut 5 degree off and the remainder are filed plumb. Another way to assist in a smooth progressive cut is to have the cutting edge of the saw plate slightly concave in shape I.e. The middle of the plate is an 1/8” higher than the toe and the heel.
I don’t like a lot of set on my saws, just enough to clear the plate through the wood, another point worth mentioning is you must also dress the teeth with a fine abrasive to clear the swarf from the sides of the teeth after sharpening. Just draw an abrasive pate along the side of the teeth twice on each side.
It cuts great, not a difficult exercise, around 2 hours from filing the teeth off to being ready for work.
If you have an old saw give sharpening it a go, it really is very simple and I must admit to finding the whole process therapueutic
I had more photos to show my workings in more detail, anyway I
Hope you found it useful.
-- No one plans to fail, they just, just fail to plan