Repairing a broken magnesium mower deck

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.

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.

1. 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.

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I just did a random search for a deck from a 1996 model 10310, and they are available as repair parts - Over $310, not counting taxes and shipping. And since a new mower street price will be about $200...

Dig a hole, Say Kadish, have a quiet mourning period, and go get her a new mower already. If she's willing to mow the lawn for you she's already a Keeper, dammit!! Stop griping and spend the money!

Buy her a Rider, even. Or a little Tractor with a mower deck.

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The Lawnboy manual says to use a Heliarc welder in AC mode & pure magnesium rod.

I would do that outside.....

Page 9-16

MikeB

I would do the bolt-on plate. There is no reason that it has to look, or be "sloppy", unless that is what you are going after.

Jon

BQ340 fired this volley in news:51abad25$0$17285 $ snipped-for-privacy@newsreader.readnews.com:

Besides that, it ain't magnesium. It's "Elektron Alloy", or more simply, a mixture of magnesium and aluminum (typically in a 35-65 to 50-50 ratio) called "magnalium".

The same stuff was used for Porshe and VW (and Karmann) gear cases for a time. When I was a volunteer fireman, I witnessed a co-worker from the radio station where I was working burned alive in a Karmann Ghia that had such a gear case.

In _any_ case, magnalium is highly combustible in air. We use it in the pyro trade as a fuel for raising the combustion temperature of 'bright' color compositions. Use an inert gas to shield it, and enough so it cools below yellow heat before the gas shield leaves the zone.

Lloyd

Unless you need the 2 stroke mower for mowing side-hills etc. No more

2 stroke lawn boys.

Just keep your eyes open for another old lawn-boy - with bad crank seals or whatever making it hard to start - and harder to sell.. Currently a good deck on Kijiji in Toronto for $15

Well, I am unable to find any new Lawn Boy 2-cycle mowers. Every

4-stroke mower I have owned weighs a great deal more than this old machine. Since we end up picking it up to mow raised areas, weight is important enough to make this a "must repair". Spending the money for a new deck is not in the picture, either.

You are right about her being a keeper, so if she says this mower need to be fixed, well...

We also have a Wheel Horse, but need the pusher for tight spots. OTOH, we are looking into getting a ZTR to replace the Horse. I tried to talk her into letting me use the finish mower I have for my 4WD Mitsubishi, but she won't let that beast anywhere on her lawn - something about ag tires and a heavy machine, whine.

This Lawn Boy is a 1975 model, BTW. They don't make 'em like that anymore!

Joe

Joe Gandalf fired this volley in news: snipped-for-privacy@4ax.com:

I've got a Scagg 61", and wouldn't trade it for cash, unless it was enough cash to buy a brand new one!

I mow 6 acres each week, and it takes only 3 gallons of fuel, and about four hours. 'Looks like a golf course when it's done.

Lloyd

Thanks Mike. I never thought to look for welding instructions in the copy of the manual I downloaded some years ago, but there it is.

Joe

So, should I (or, more likely, the shop I take it to) still use the pure Mg rod, as the manual suggests?

Joe

Joe Gandalf fired this volley in news: snipped-for-privacy@4ax.com:

Yup... just lotsa-lotsa inert gas and a low enough amperage so that you can have the weldment cool enough before leaving the gas shield.

Magnesium is fine for welding magnalium; though not quite as strong.

The aluminum was originally added simply because magnesium alone doesn't pressure-cast very well without crystallizing (fractures), and doesn't have the tensile strength of magnalium. The aluminum makes the mix more plastic.

Lloyd

"Lloyd E. Sponenburgh" fired this volley in news:XnsA1D3C30DC2DA6lloydspmindspringcom@216.168.3.70:

Oh... it doesn't make a weldor happy to see the bottom-side of the work catch fire, so gas should be applied to both sides of the work.

Lloyd

Purge box, even a taped up cardboard box enclosing the deck with just enough access to get to the weld area. Pre-purge with plenty of argon before welding, set post flow to the max time available.

"Pete C." fired this volley in news:51abd6b7$0$17298 $ snipped-for-privacy@newsreader.readnews.com:

Yeahbut... if you see how big a light a pure Mg rod makes, you may want to think twice about using cardboard for the box .

Lloyd

I'll never understand why otherwise sane people want so much farkin', blasted grass. Wasting good time, money, gasoline, fertilizer, and ungodly amounts of water on something which maked their allergies flare up and their noses run is beyond me.

Some books for those people:

Beautiful No-Mow Yards: 50 Amazing Lawn Alternatives by Hadden, Evelyn The Edible Front Yard: The Mow-Less, Grow-More Plan for a Beautiful, Bountiful Garden by Soler, Ivette

Lawn Gone!: Low-Maintenance, Sustainable, Attractive Alternatives for Your Yard by Penick, Pam

The New American Front Yard: Kiss Your Grass Goodbye by Sarah Sutton (My sister edited this for her friend Sarah.)

Food Not Lawns: How to Turn Your Yard into a Garden And Your Neighborhood into a Community by Flores, Heather

Cheers!

Larry Jaques fired this volley in news: snipped-for-privacy@4ax.com:

FWIW, Larry, I water none at all. I fertilize none at all. I mow simply because I want it to look nice.

The cows do the fertilization, and Florida does the watering. If it wilts in a drought, I just don't mow.

If I made $30K a year, I wouldn't consider it. I'd just let it grow. For now, I can afford the gas, and can _almost_ afford the time.

What if you just called it a "hobby". Would you object to spending the money, then?

LLoyd

I've made a similar pitch to Angie, but to no avail. I guess it's the English part of her heritage.

Not as bad, though, as when I used to tell her to stop wearing herself out raking the damn leaves. I would say "They call them 'leaves' because you're supposed to *leave* them alone." I used that line one too many times. Now I just shrug.

Lest anyone think I just lay around the house, I do all the maintenance work on all equipment (I call it "work" when Angie is around), run the bush hog, cut down trees, then cut up trees (the 2 jobs seem to be at odds with one another), dig holes, build greenhouses, etc, etc. I'm getting worn out just thinking about it.

Joe

If she designs the patch it won't be ugly. Cardboard from a cereal box etc makes a good pattern that you can trace onto sheetmetal. jsw

FWIW, we had a Sears/Power Products mower with a mag-alloy housing that my dad bought in 1959. It was light as a feather and I loved it. He got a newer mower but I would only use the light one. It had a

2-stroke PP motor with an aluminum cylinder, with no lining, and an integral head that didn't come off. No throttle and a wrap-on rope starter.

In 1962 - I remember the day -- I hit a rock that flew forward and cracked the front of the housing nearly off. It was held on by a thin steel "comb" on the front of the housing, which was held to the housing with two or three rivets.

When I read about your situation I nearly fell off my chair. It sounds like the same thing.

Anyway, my dad cut a strip of 1/8" aluminum about two inches wide, the langth of the crack, drilled holes, and screwed through the housing into the aluminum. It clogged easily if the grass was wet but we used it like that for another two years.

'Hope you can keep it.