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Anyone ever weld a cracked exhaust manifold? The passenger side on my 440 split, so I found someone to weld it. Apparently there are 2 ways to do this, the right way (involves an oven and slow cooling the piece over a few days)and the wrong way (gas welding). Has anyone had experience with either method? I haven't had a chance to try mine out yet (see my other post about broken studs and heli coils...)
william
 

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Cast iron manifolds can be brazed (sp?) ( hi temp brass soldered), It takes someone who KNOWS what they are doing. Try talking to your local welding shops - maybe look for one that works on heavy duty farm equipment.
 

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I have used a product from Por 15 on an old Ford Galaxie I used to have. It worked awesome and only $10. It's called Fireseal 2000. My old Ford was a POS, the passenger side exhaust manifold would always glow red hot. This stuff held up in those conditions for 2 years. I got rid of the car and I guess its still there.

http://www.por15.com/product.asp?productid=7

Streak-O-Lean
 

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ok cast iron can be "welded" with most all processes including MIG TIG SMAW Carbon arc plasma and oxy-acet. it just depends on prep and filler material. cast isnt ductile so when the weld cools rapidly, the bead pulls from the base metal (the cast) since the cast doesnt stretch much. things to ensure are a clean weld surface, v groove and slow pre heat post heat. it can be done in a barbeque grill or a hot oven. i forget the heat and cool intervals and temps. ill try to find em.
beleive peak temp is some where near 500º
brazing rods, high nickel rods, cast iron rods, 300 series stainless rods have all been used to weld cast iron. mild steel could be used under certain circumstances. it would be much harder to do though.

im gonna vote for braze becuase it uses least expensive equiptment (just a torch) and while, hard, is easier than most other options. plus the bronze isnt actually mixing with the base metal which can pose a problem with the other process. carbon is drawn out of the base metal and deposited into the weld bead, weakening the surrounding base metal.

just pay attention to prep and pre heat and dont weld for too long. if the crack is big, do it in sections allowing the metal to evenly heat back up in the grill or oven.
 

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Dare I say it again... JBWeld?
I've seen cast manifolds brazed pretty quickly -without the long heatup-cool down cylce- because the brass melts at a lower temp, and if there's room for it to run into the crack, and the crack edges are jagged enough, the brass will hold pretty well.
 

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I've done a couple. I use an old steel rim, with 10lbs. of charcole, and bury the manifold. Cast iorn is a real mother f*%^ker to weld, and no matter who does it, there's a 50/50 chance it will/won't work.
 
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