Interesting thread.
Funnily enough I sharpened one (straight edged) only yesterday
Can I ask Dave, how do you top the teeth when they are on an arc? I cant figure it out. I thought something along the lines of a plywood template you could use each time, that was the same size as the tooth arc less an inch or so, then run the file against the plywood, like using a marking guage?
As for rust removal I am a big fan of elctrolysis. It workks a treat and can get amazing results. Basically its metal plating IN REVERSE, in a vat of washing soda or caustic soda in water, you use the electric current from a car battery charger to cause the rust and soot and cement, paint grease etc etc to loosen. You attach one clamp (neg) to the rusty item, the other (posi) to a piece of steel scrap (anode) which you also submerge in the vat. The gunge is attracted to the anode. It takes a day or so. Then you just need to use a plastic brillo pad to gently clean off the jelly type remains, then rinse, dry and oil or wax. The method wont attack sound metal, only rust and other oxides. No kidding I got some disston saws that literally looked like time team relics, coated with concrete, rust, paint etc. Very sadly abused. BUT the process restored them fully, to the point that the fine and delicate makers etch was uncovered undamaged. I paid about 40p each for the saws. I was selling them cleaned set and sharpened for up to £32.
But yeah they're cool and they do keep the midges away if you run them a little oily.
