# Cast iron welding



## markturner (30 Apr 2014)

Hi, I may need some cast iron welding done on a recent purchase ( quite exciting, further details to follow) ....I understand this is not a straight forward or easy thing to do. is there anyone here who knows how to do it, or knows of anyone who could do this?


----------



## mind_the_goat (30 Apr 2014)

As I understand it the heat stress caused by the very localised heating during welding can often cause the material to crack. The trick seems to be to preheat the work before using the welder, a gas torch would do the job. Not something to try without a bit practice first though. Not sure if gas welding on it's own would be easier, probably give you a more even heat distribution.
If you don't get any recommendations then I guess you'll just have to ask a few searching questions of anyone you find who claims they can do it.


----------



## Spindle (30 Apr 2014)

Hi

It's possible to MIG and MMA cast iron but the degree of success will depend on the size and profile of the component to be repaired. Pre heating of the component will be necessary as will controlled cooling.

Not a job for an amateur

Regards Mick


----------



## nathandavies (30 Apr 2014)

I had to get a machine welded, the guy that did it was incredibly knowledgable. there are a lot of people who do welding on cast, but from speaking to the guy that did mine it looks like not many do it correctly. I would say that if the part involved will be supporting something that for instance spins at high speed and could cause potential injury if it fails, then I would want somebody who is an expert in these things. if it is say a leg on a machine and less dangerous then maybe learn what you can and have a go. unfortunately specialised welding can be extremely expensive, and cost more than rebuying a machine. sorry to sound like a killjoy, but it's safety based.

looking forward to seeing this exciting item

nathan


----------



## markturner (30 Apr 2014)

Hi, thanks for the advice, I am in central London, and certainly wont be trying it myself, so if anyone can recommend someone I would be obliged. 

The item in question is an outrigger table for a Wadkin PK saw........a rare beast indeed, but needs welding


----------



## spinks (30 Apr 2014)

Its expensive....I have welded cast using MMA (stick)....plenty of preheat, a good prep, a good tidy weld and controlled cooling...the rods are extortionately expensive and you are liable to cracking in the area around the weld as things cool but it is do-able....A retired welder type chap who has been round the block a few times and has time on his hands is someone to look for! Good luck


----------



## dickm (30 Apr 2014)

May have been beginner's luck, but have successfully welded a couple of vices (don't ask how they got broken  ), which are still taking a lot of stress. The key points, as others have said, are pre-heating the whole thing if possible to as high a temperature as you can, using the right electrodes for the job and cooling as slowly as possible. 

Up here, there are so many guys who can weld (even under water!) that it's easy to find specialists. But possibly not round London, where playing with money seems to be all that happens.


----------



## n0legs (30 Apr 2014)

Try your local college of knowledge.
A donation to the tea fund might suffice.


----------



## Limey Lurker (30 Apr 2014)

If you are looking for a cast iron REPAIR then why not consider Bronze welding? It's a very common method.


----------



## Flatlander (19 May 2014)

As regards cast iron welding, most people do preheat it. If you ever do one of ESAB's courses, they will tell you to cold weld it, and have a specific method for doing so.


----------

