A useful tip I found when fitting new alloy wings recently. I'm useless at using tin snips, but found that a big sheet of insulation foam - the stuff about 6 cm thick laid down on the garage floor supported the wing edge. A double thickness could be used when necessary. A metal blade in the jigsaw then cuts through the supported metal and insulation foam. I found I could remove a mm at a time very accurately even over long distances. Before rolling the edge over the inner wing, anneal the aluminium by scribbling magic marker on the area and heating with a blowlamp until the scribble disappears. A lot easier than using soap to get the temperature correct.
