www.ultimatehandyman.co.uk

Hi all,i need to weld a cast iron engine block,i thought about using dc stick welder,i was searching ebay for cast rods and read that the seller said that his rods worked better on ac,so what is it ac or dc,can somebody point me in the right direction.Thanks.Ronnie.

I'm not a welder, but I do know it's very difficult to weld cast iron successfully. I had the same pair of Collinge hinges repaired a few times for one job, it never lasted very long.

heeelllooo and welcome bigman1
welding cast is a highly skilled job with limited sucsess in all but the best hands

Have a look at cold metal stitching http://www.lockstitchuk.co.uk/id110.html

This is a safer repair method as there is no heat required but I suppose it will depend on where the crack is. Might be worth having a chat with this firm.

DWD

My father was a welder and i remember going to help him on a job many years ago, it was a cracked block on a tractor, and he welded it in situ, as i remember he veed the crack, used an arc welder (stick) cast iron rods and heated up the job until it was cherry red , he told me to weld cast iron the job has to be heated cherry red and kept cherry red

I'm interested to hear how he heated an engine block up to cherry red in situ on a tractor.
...or have I somehow misunderstood your post?

It would be easier to get a new block than have a lasting weld on cast, it will crack very easily next to the welded area.

welding cast engine not recommended, cast has to be heated not to cherry red but hot very hot when weld completed it should be allowed to cool very slowly by covering welded area with warm sand or thermal insulation or even submerged in oil? ac welding alows impurities in welding to raise to the surface of the weld on the current alternating between positive and negative, dc welding is direct current electrode is either positive or negative. it should state on the cast iron rods wether it should be +positive or -negative.