Has anybody tried "Metal Mend". I saw this stuff at a bike trade show long time ago. They were repairing typical alum/magnesuim alloy engine cases; the guy was drilling holes through and then soldering them up. With some polishing the repair was invisible. I was very impressed since cases are really hard to weld without making a mess. Anyway, this stuff is a high temp aluminum epoxy that is super strong. It is inexpensive and comes in packs of rods, each about the size of a 1/8 arc welding rod. I have used it a bunch of time for various repairs. Heat the item with a propane torch and melt the stuff on like brazing. With the propane torch you almost can't melt the aluminum, so you can repair small finiky items (without destroying them) like a float bowl etc.. I just used it again last night and re-remembered how handy it is. I'll try to find a link for more info and a supplier and post it. Cam.
