My wife loves her old Lawn Boy push mower; it's very lightweight (esp.
since I removed all the Rube Goldberg self-propelled mechanism) and
easy to start - still! However, the magnesium deck has developed a
crack that runs across the front of the discharge chute. I was going
to bolt a metal plate across the crack as a repair, but it would be a
really sloppy patch.

The more I look at it, the more I want to weld it, but I know what Mg
does when it gets hot enough to burn! Is there a way to do a decent
join without destroying the mower? I only have a Lincoln tombstone AC
welder, a cheapo HF DC Tig, and O/A gas setup. I also still have some
of those "miracle" repair sticks that used to be touted at flea
markets ("fix any Al device with just a propane torch - developed by
NASA").