Welding experts needed

Fritz Maurer · Apr 1, 2012

Need to repair a casting about the size of a 8-N center housing, but it's 3/4" thick. No broken pieces, just a split from frost. Would like to braze it, but how can you get it hot enough with a brazing tip? Any other ideas welcome. thanks, Fritz

wisbaker · Apr 1, 2012

Friends welded up the rear housing of a crawler, had about 150 pounds of charcoal going under it to preheat the casting. with brazing you only have to get the area you're working on red hot, if you get to much heat in the casting you risk cracking it when it cools. Don't do the charcoal thing when friends are around, you'll get teased about barbecuing your tractor and asked what kind of sauce goes on barbecued John Deere

teddy52food · Apr 1, 2012

BBQ grill. Vee it out good & drill a hole at each end of the crack.

IaGary · Apr 1, 2012

I've had pretty good luck cold wire welding cast iron.

Put a grinder to the cast. If you get yellow to orange sparks off the cast it can be welded.

Vee out the crack with a grinder then weld it slow.

By slow I mean weld a 1/2 inch or so and let it cool then go again till you have the void filled with weld. NEVER allow the cast to get hot.

I have welded the exterior of engine blocks this way 3 or 4 times and have not had a failure. One had a slight seep but never a leek.

Gary

barnE · Apr 1, 2012

Preheat but not red hot. Black rods. Forgot what they are. dave

Anonymous-0 · Apr 2, 2012

Use a propane weed burner to preheat it and you could also use it to keep the piece hot and slow cool it. They aren't too expensive and you can probably rent them too. Just hook it up to BBQ tank. If you use a grinder to V out the crack, use a carbide burr or file to clean up after the grinding.

johndeereman · Apr 2, 2012

Just use a mig welder

Welding man · Apr 2, 2012

Lock and Stitch.

NCWayne · Apr 2, 2012

I've brazed some relatively heavy castings over the years, and have watched the old fellow that used to be our 'go to guy', until he passed away, braze up even heavier castings like the one off of a press head he had in the shop some years back. In every instance the best was to heat the thing was one of the 500,000 BTU, propane, weed burners. Once you have the casting to say 300 degrees or so, it's not that hard to get the spot your brazing hot enough to melt the brazing rod. The main thing is to V out the crack and get everything as clean as possible before starting. I've found that the hydrocloric acid solution you can get that's designed for cleaning RV water tanks (I think that's the use listed on the bottle) does a really good job of getting cast clean enough so the braze will bond and flow properly. The pure stuff works great too but it's not readily available anymore like the dilute stuff is.

Fritz Maurer · Apr 2, 2012

Funny you should mention that... it's a transmission housing on a small Cat grader.

Welding experts needed

Fritz Maurer

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wisbaker

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teddy52food

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IaGary

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barnE

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Anonymous-0

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johndeereman

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Welding man

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NCWayne

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Fritz Maurer

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