Welding Tips and Tricks

I have a turbo exhaust manifold i want to a external waste gate, the gate housing is 308 SS the Exhaust manifold is used. Preheat? no Preheat? Filler wire? Tig or stick?

Map

It can be done but will be rather brittle. you will need to pre heat the cast, clean and grind a bit. then clean some more. then weld a layer of 309 , 312 or eni-ci rod to the cast a little at a time from one side to the oppisite side. the eni-ci is probably better. try not to use too much heat. dont cool the piece until all the welding is done. then weld the s.s. part to the cast. keep cleaning as you go (removing all slag) and keep welding back and forth from oppisite sides. when your done try to cool it as slow as possible. I have used a pre heated oven for smaller parts in the past. remember it will probably be brittle and no guarantee of not cracking. pinging the cast as you go probably wont hurt either. hope this isnt confusing. good luck.

I'll give it a shot. This is the manifold.

Here is a good reference for cast-iron welding:
http://www.lincolnelectric.com/knowledg ... reheat.asp

I have repaired cast-iron by both methods mentioned. From what i see in your pic the method that I would elect to use would be a preheat.

Heating in a gas forge or a high temperature kiln to the required temp would be my preference, then wrap the part in a blanket of kaowool or other high temperature insulating blanket so that it doesn't cool much while you are welding. Once the weld is completed an anneal phase in the same kiln would be in order.

I have repaired small sections using the cool method mentioned in the article. I usually weld about 1/2 inch or so, I have used a factor of 1 to 2 times the material thickness as a bead length, peen it while it cools with a round nose chipping hammer or such, then let it cool till I can rest my hand on it... without pain of course, then lay in the next bead.

The preheat is the most successful for me. I have seen brazing used to repair fairly heavy sections, but the mass that you have to weld is considerable, and it looks like you would have to spend as much time preheating for the brazing as you would for welding.

Is it possible that you could simply tap the hole that leads to the part that you are trying to weld on and screw in a schedule 80 or 160 pipe nipple and transition to the outside world trough that?

good luck

Ironmonger, your last suggestion is a piece of out-of-the box magic! I'll have to remember that