Question for the welder guys:

[Ozona]

After going through this:

http://67-72chevytrucks.com/vboard/s...d.php?t=240708

I've found that I need to modify the main air conditioner bracket so it will bolt up to my "stock port location" Merlin cylinder heads...because it's not EXACTLY in the stock location.

SO...that brings me to my question.

Can I weld mild steel to cast iron with my MIG to "fix" my AC bracket? If so, what do I need to do it?



LOL..

[tkeduk8r]

Well, my immediate response would be no... well at least not with the mig... I used to to tell my former metal shop students that its always a bad idea to try to weld dissimilar metals, HOWEVER, i am not a welding guru, and they do make some pretty funky welding rod combos for arc welders. AND I would say your not the first guy to have that issue. Im am interested to know if some of the pros know the answer for sure... if anything else.. ttt
--Mike

[bcanini]

I'm not saying this will work but you should have a good chance of getting it to stick. I've always welded cast w/ Ni rod (nickel cadmium) prepare the joint, get a torch heat up the cast until it's cherry red (very important) not orange.
Tack your pcs on if it loses it's cherry while your doing that preheat it again to cherry, weld pcs on and postheat to cherry wrap in normal fiberglass insulation and let cool slowly. when it cools give it a rap w/a hammer if she sticks she'll stay.

Brian

[mrein3]

Originally Posted by bcanini

I'm not saying this will work but you should have a good chance of getting it to stick. I've always welded cast w/ Ni rod (nickel cadmium) prepare the joint, get a torch heat up the cast until it's cherry red (very important) not orange.
Tack your pcs on if it loses it's cherry while your doing that preheat it again to cherry, weld pcs on and postheat to cherry wrap in normal fiberglass insulation and let cool slowly. when it cools give it a rap w/a hammer if she sticks she'll stay.

Brian

Though I've never done it or seen it done my welding instructor outlined the process bcanini wrote up.

Use a high nickle rod.
Pre-heat the cast piece.
Weld the part.
Slowly cool the piece down.

The instructor added that in production facilities that do this regularily they use an oven to heat it up and cool it down at specified rates.

The only difference in what I HEARD (again I've never tried this process) is that the instructor said you can place the piece in sand to insulate it and let it cool slowly verses using insulation.

[Bus Ted Knuckle]

Originally Posted by bcanini

I'm not saying this will work but you should have a good chance of getting it to stick. I've always welded cast w/ Ni rod (nickel cadmium) prepare the joint, get a torch heat up the cast until it's cherry red (very important) not orange.
Tack your pcs on if it loses it's cherry while your doing that preheat it again to cherry, weld pcs on and postheat to cherry wrap in normal fiberglass insulation and let cool slowly. when it cools give it a rap w/a hammer if she sticks she'll stay.

Brian

This would be absoloutly correct IF you were welding two pieces of cast iron, or fixing a crack in a piece of cast iron. But that is not what you are doing. You are welding a piece of steel to a peice of cast iron. My 2 cents are that that is not going to work out for you becasue they are two different kinds of metals.

I think you would be better off trying to locate another bracket that would work, or fab up another bracket out of all steel.

[LooseCannon]

ttt - I'm curious as well.

[bcanini]

I was just saying it might work, I'd try it on a scrap pc if it was me.


Brian

[Bus Ted Knuckle]

Hey Brian, i'm not flamin you I am sorry if it came across that way. I totally don't want you to feel like you can't share your ideas.