Following an argument between the sump and a manhole cover, a couple of the mounting lugs that connect the block to the gearbox bellhousing have snapped off.

So I thought I'd just weld them back on but I was looking on www and there's advice that using conventional MIG welding techniques won't work - something to do with the characteristics of cast iron.

Anyone tried welding their block before and how did it work??

Thanks Alex

Had the same with an engine i bought from a write-off years ago, the gbox lug had sheered off the block.

Arc welded it back on OK.

Use an arc welder and dis-similar metal rods. Should be OK and leave a neat stainless weld. Mig will look to weld OK but will snap like a carrot.

Yep Migs no good for cast. Iv tried it before. The bits will just fall off.

It will look to weld with mig but it will go ting ting ting as it cracks whilst cooling.

Arc weld as above but heat it first and cool it slowly.

A mate of mine welded a cast V8 daimler block with a MIG, and it ws ok. That was in a hotrod, so it had the tits thrashed off of it regularly.

Very difficult to repair cast iron, some restorers heat up the part to 400 degs then weld the repare, wrap the repaired part in insulation and leave to cool slowly over a period of days.
Esslinger engineering recomend (when welding cam tower straps on a Pinto) using silicon bronze wire and Heli Arc

I MIG'd a cast iron exhaust manifold on a cossie YB a while back (needed to do a cut'n'shut on it to move the turbo) and that worked a treat. Lasted for the next year until I sold the car anyway, and probably saw some huge temperature variations.

Gary

hi, you need to stick weld it with cast iron rods pre heat and controled cooling we used to put cast bits in a big tub of lime after welding.
you can take all the coating off cast iron rods and use as a filler rod to tig cast iron but it will be brittle.
the above turbo manifold would be a completely different type of cast to your block
Ray

[Edited on 14/2/10 by RAYLEE29]

oh you can of course braze it vee it out first for more strength
Ray