On Sun, 02 Jun 2013 14:09:16 -0400, Joe Gandalf
wrote:

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").

1. Call LawnBoy (or get on the Interwebs) and see if you can get a
new deck casting, and move the motor and all the other parts over.

https://www.shoplawnboy.com/Comergen...ineModelLookup

1A. But first, do a financial study - the replacement deck part might
cost you more than a brand new mower, and you get a zero-hour engine,
new blade, etc. for that price.

The MSRP for the Manual Push model is $259, and if you can't beat that
price by quite a bit you aren't trying very hard.

2. Find a local Aluminum Casting foundry. and take them the stripped
bare mower deck casting to use as a casting blank - they'll probably
want you to fill in the crack with Bondo and fill in any drilled and
tapped holes that you'll need to drill and tap yourself on the new
casting.

It will weigh a bit more in an AL Casting Alloy rather than Magnesium,
it will be a little rough from the sand-casting (unless you spend a
lot more to make an injection mold like Lawn-Boy did) and it will Not
be cheap (it would be certifiably insane 10X the price of a new mower)
- but it'll work.

-- Bruce --