Welding cast block?

[71 Blazer]

I have a bit of a problem. I have a mud bog to go to on Friday and need my 76 GMC to go. I recently found out I have a cracked block, I thought it had just popped the freeze plug. I have a mig welder and think I can weld it up. I have never welded on cast before. I have read that it should be heated up with a torch first so it isn't so much of a temp change, is this right? Any help will be appreiciated. I am going to put the freeze plug back, and will check back with you guys in a bit.

 

[odin]

Clean the area real well and use JB weld. Trust me Ive done it before, let it harden before filling the block and it should last a long time.

 

[Thunder]

To weld cast with a MIG you need special wire. The stuff works but is not cheap. There is a way to MIG cast using Cast NI rod similar to TIG welding But I have no idea how to do it.
Most of the time cast is welded with an Arc welder using special rods for cast iron.
Unless you really know what you are doing, you can cause more problems by welding cast than you will solve.
IMO JB weld is your best route. Even if you weld the cast. It may, and prolly will crack by the welds when it cools and you will need to use the JB anyhow.

 

[71 Blazer]

Yea I figured out that JB weld was the way to go. It is on right now I'll tell yuo guys how it goes tommorow.

 

[Drey]

I wouldnt be worried about JB weld at all. My buddy has had it on the block of his Honda Fourtrax for the better part of 8 years now

 

[Streetgliderx]

i have welded cast with nickle rods but its not a good resort. poor casting will have pits and it never tends to weld good enough to rely on. jb it cause i weld for a livin and i still don't recommend it

 

[blazin_blazer]

for future refernce

http://www.lincolnelectric.com/knowledge/articles/content/castironpreheat.asp

 

[wasted wages]

also:

http://www.locknstitch.com/Metal_Stitching.htm

 

[71 Blazer]

The JB Weld is holding fine. Thanks for helping me out by not letting me weld it with my mig welder.