magnets that is a class idea.
Old people are full to the brim of good ideas.
This is because we made all the possible bloody silly mistakes long ago, and then sat down and worked out how not to get into that sort of stupid mess ever again. I could tell you horror stories, but I ain't going to. :doh:
Filling an engine with hack-saw filings is a very bad idea.
Washing them out afterwards only spreads some of them just where you don't want them to go. Far better to capture them right as they come off the blade.
So you go get an old speaker, rip it apart, and take out the ring magnet.
If you can find several, grab them.
Split off the metal plate on top, and remove the bottom plate that has the centre boss on it. All you want is the black ferrite ring magnet.
Try snapping one of the magnet rings into smaller pieces, and then you can fit the smaller bits really close to the cutting zone.
OK?
CharlesY