# MIG welding a cast iron exhaust manifold.



## aametalmaster (Feb 18, 2012)

You guys know how hard it is sometime to weld an old junky exhaust manifold? I have done hundreds of them over the last 34 years most of them stick with Ni rod and some brazed. Some worked well some didn't. So move ahead 30 years i picked up some Crown Alloys .035 44-30 mig wire for cast iron. Its used with Argon and works great. This manifold on my Geo Metro had a crack and it has been hissing for 4 months or so. I drove the car around to warm it up since i wasn't planning to remove it and hit the crack with a die grinder and a stone. Then i dabbed the mig wire in the clean area and triggered it right up the crack. It took about 30 seconds and sealed the crack right up. I let the car run for a few minutes and then let it cool. So far so good. The 2# spool is 75 bucks and i wanted to try it out for a test...Bob
http://www.crownalloys.com/TechSheet/CAST_IRON_ROYAL_44-30_w_New_Warning.pdf


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## irishwoodsman (Feb 18, 2012)

here is another option, silver sodder, they make a rod now you can use with a propane torch that works beyond belief, never thought it would work untill the ramhorn manifold broke on my chevy truck, ordered the rods and got them in just to try with doubt, but guess what it worked like a charm:biggrin:Mac


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## 8ntsane (Feb 18, 2012)

Bob, & Mac

Good tips to know
I have also welded up many exhaust manifolds over the yrs, and like Bob said some where sucessful, and others, well. Allways good to know there is other ways and products available. I seemed to have problems if I didnt pre heat the metal. If I didnt, it seemed to recrack again.

Thanks for sharing guys


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## pjf134 (Feb 18, 2012)

It's been a long time since I have welded cast, but I always prep and heated with torch then used stick rod for cast, mainly used machinable rod to finish nice, but have used non-machinable rod in some cases and never had a problem. I have never tried Mig yet, so it's good to know what works for somebody else.
 Paul


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## aametalmaster (Mar 17, 2012)

I have over 3,000 miles on the weld and its still fine...Bob


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## irishwoodsman (Mar 19, 2012)

ebay item number 330302632224 and it does work great​:biggrin:mac


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