Welding Cast Iron
Pro
Joined: Mar 2001
Posts: 633
Likes: 1
From: Hamilton, ON, Canada
Originally Posted by Michel B
I've welded many exhauste manifolds with excelent results,, weather with a stick or tig,,, the secret is pre-heat the whole part to about 500 to 600 deg, weld, and place it back in the oven and turn off the heat, let cool down 24hrs, you can allso bury it in asbestos powder, or even sand work good,, the idee is to let it cool very slowly and evenly. You have to make sure you have the proper welding rod. 
Melting Slicks
Joined: Jun 2003
Posts: 2,490
Likes: 0
From: A high school diploma fixing what a college degree broke TN
St. Jude Donor '03 thru '26
I've welded cast iron for people before who didn't think it could be done.As stated by others ahead of me,the secret is in the pre and post heating of the part.The times I did it,I slowly brought the part up to a high temp with a torch,depending on the condition of the iron and how much material was left I ground a V in the crack or not.I then used a arc welder with a nickel rod,after welding I put the torch back to it and over 15 minutes to a half hour slowly brought it back down,then air cool after that.I would think that with the same preparation brazing or TIG would work,with the nickel rods used I have yet to have anything break again after I welded it. 
Le Mans Master
Joined: Mar 2004
Posts: 7,477
Likes: 1,495
From: Little Rock AR
Originally Posted by bobs77vet
cool site thks for the reference, have you used the cast iron machine grindable rod??
As for the fancy Muggyweld rods, I have not used them but they look nice. If I ever need to buy some, I will try them.
-Mark.
