Welding castings

Just a quickie. I'm going to have a go at splitting my exhaust manifold soon. Q. Is it OK to tack everything together and then preheat, or should I preheat first. Q. 2. MIG, TIG or bronze? After welding I'll chuck it in a bed of lime, yeah? Although my welding skills are pretty good I'm not an experienced welder.

Thanks

Louie

 

I've never welded a cast exhaust manifold.

Saw my dad do it; stick welded with a high-nickel rod he called "ni-rod". He'd do 2-3 passes; with each pass peened heavily with a hammer before the next one went on.

No pre-heat.

Looked like shit, but held for years.

There's also a guy north of here in Arlington, WA who specializes in welding cast iron. Stopped by his shop with a Model A head one day; he had piles of cylinder heads in there.

I've seen a few pieces he's done (the head I brought, plus model A block and '50's Jimmy head) that looked absolutely beautiful.

Not sure, but think he furnace-welds the stuff.

-Bill

 

They say the 3 P's apply to welding cast iron. Preheat, Postheat and pray.

Use a high nickel rod, I Tig weld it when I do it, preheat it an oven then let it sit in the oven for several hours after welding. I have been successful so far, but only done it a handful of times.

 

Not all that complicated.........go to a local welding supply store and ask for cast iron specific rod for stick welder........follow instructions........preheat with a torch of some kind.........even a Bernz-O-Matic propane will be sufficient......short beads, keeping the heat with torch as necessary and when finished, put in a box or bucket of sand to let it cool gradually..........worked fine for me.........the cool down is the main thing......cool too fast and it will "ping".........meaning it just cracked somewhere next to the weld. If that happens, V grind crack and follow the steps again, most especially the haet and slow cooling process in sand or lime.

Ray