welding a mower deck

Any metal can be welded. But the thin steel on a mower deck will require a wire feed welder. A stick welder will burn thru. Before you weld it, or take it to a pro welder, clean all the dry grass off the bottom or it will start burning, and if you're paying a pro $60 (or more) and hour, you dont want to be paying $20 to $40 for him to clean off the grass before he can weld it.

I had a deck crack and one wheel was really bent outward. I tried to weld it with my stick welder and after learning that the dry grass would start on fire, and having to clean it off first, I tried to weld it, but I burned thru the metal. I took it to a welding shop and $25 and 10 minutes later he had it all patched up. It worked another 2 years till the engine died.

Or weld it with a torch set. But that's becoming rare these days.

Mine cracked around one of the anchor points - it does seem to be a bit of a weak spot, particularly as the decks age and rust takes its toll. Rather than try to weld it (I was worried about it burning through, too) I bolted some 1/8" plate over the crack top and bottom to spread the load across a wider area. It's been like that for a couple of years now and hasn't broken yet.

cheers

Jules

It was designed to throw away and buy a new one.

Not so much. The torch set nowadays only consists of the torch an a bottle of acetylene. No more needing a separate air tank. The torch mixes the acetylene with the ambient air. Plumbers still use them.

That's fine for plumbers but you need both tanks to weld. I still have a small set. I'm only passable at all welding but I found that for general purposes a tank set is more useful. I can braze, I can cut, I can weld, I can heat things up. Other solutions only do some of those things.

Over the years I've found brazing a patch on works best. Usually with an Oxy-Acet. torch, but TIG works real well too.

That works for soldering, and limited brazing - but welding still needs oxygen - and the process is still fairly common

Or MIG with a 1/8" flat bar backing plate works for me. Drill a hole at the end of the crack to stop the crack, and put a HOT spot weld there. "Stitch" weld the rest, using short tacks or short (1/4") welds.

Steve (Retired certified welder)

Not adequate in attaining the temperatures necessary for OA welding. Good for sweating and maybe brazing, but not welding.

Steve

good points! Thanks much.

that's an idea...but drilling through steel has to be fun

lotsa bux!

Chuckle. I once had an 83 Mustang, and the floor under driver's seat developed fatigue cracks at the angled parts of the stamping. You could feel it flex as you sat down, or went around corners. I didn't feel like stripping entire interior, and couldn't afford to pay a pro welder anyway. I repaired it by gusseting it on top side with some 1-foot square plates of 12-ga galvanized flashing I was able to liberate and blacksmith into the needed shapes, with a layer of tar underneath, held together with a whole bunch of peened-nut fender-washered (underneath) grade-8 bolts from Tractor Supply. The patch probably weighed 30 pounds, but it held as long as I owned that POS car. You could barely feel the lumps from the bolts through the carpet. Up on a lift, it looked like Frankenstein's monster.

Reminds me of First Car, a 76 Buick Skyhawk, bought in the late-80s. It became hard to shift because the firewall where the clutch cable passed through had fatigued and cracked into a star pattern. Pushing the clutch pedal down pulled the clutch cable sheath through the firewall, sort of--it was still attached to one of the "spokes", which resulted in a creak. A scrap piece of sheet metal bolted over the hole held the clutch cable in place for the rest of the car's life--which wasn't long...

Just a couple years later, I took it to a shop to track down some creaking and alignment problems. The guy took me down into the pit to show me how the body was ripping apart where the front suspension attached to it. He said it really wasn't safe to drive.

When GM imploded I was thinking that probably everyone still alive who had anything to do with producing that POS was collecing a nice plump GM pension.

The reason it broke is because the metal rusted and/or wore away.

You can weld it but you're just sticking the fatigued material back together, and not doing a thing about the fatigue. Odds are good it will break again in a short time.

Not only do you need to weld, you also need to add a patch to reinforce the worn area.

In MOST cases wear is not involved - vibration (fatigue) is. If you make sure it cools slowly after the welding, it can be annealed and the built-up stress relieved, Not saying it won't crack again a few inches away. If not badly rusted I've had good luck drilling the end of the crack and brazing it up.

You'd have to make it stick well enough to withstand the vibration - and that means it needs to be CLEAN. I've never seen fiberglass stick in such an application. I've seen lots of "trys"

Even clean, where most of the deck cracks I've experienced occur, they would pop most fiberglass and/or epoxy patches