Welding cast.

[shumungus]

OK, have a bit of welding to do involving MF weight slices, would I be right in saying they are likely to be cast steel? Anyhooo I am capable enough with MMA and MIG on mild steel but have no experience to speak of on cast. I will be welding cast to cast and cast to mild.
Hints and Tips greatly appreciated, rod type, ve + / -, pre-heating, preparation etc.
TIA

 

[Tim G]

I've never done it personally but you need special rods for cast and the pieces being welded need heating up first.

 

[traineefarmer]

Nickel or dissimilar rods specially specified for cast to mild. Pre-heat the cast before welding - you are going to need a lot of heat to get a weight hot enough - you'll need a special heating nozzle for your torch.

A little background on your project would be helpful, but I wouldn't expect any joint on a weight to be particularly strong, especially to mild steel. Weights tend to be made from very low quality iron with lots of impurities which will make achieving a successful joint almost impossible.

 

[Bloders]

cast iron is NOT the same as cast steel.
I would imagine you weld cast steel in much a similar was as steel

 

[traineefarmer]

The non-metallurgist way to find the difference between cast steel and cast iron is to grind a piece back to clean and shiny then rub a clean finger on it. If your finger stays clean, it's steel. If you get a black or grey finger it's iron thanks to the carbon impurities coming out.