Welding Tips and Tricks

I have question for you guys. From time to time, I need to make repairs to some item where I would need to re-drill or machine the part after welding. I have notice that welds made using the MIG process are very hard. You can grind them but re-drilling or re-machining the part is pretty much impossible. Generally when I need to do this I TIG weld the part and the weld is much softer. There are time when I do not have the ability to TIG weld the item.

Question, is there a way to MIG weld a part and get a soft weld?? I am using C25 gas with the MIG machine. Would straight Argo work??

I'm puzzled by your experience. I've re-drilled many items after mig, stick, or tig welding.

Mig and tig wire are generally both 70s-2 or 70s-6. So are both 70,000 psi filler.

As mentioned it's not likely the filler material itself - more likely the part you are building up has sufficient carbon content that the weld is picking some up by dilution & the mig welds cool quickly enough in a small area by the mass of the part to at least partially harden it - if the size of the part allows normalizing will correct this or pre-heat the part so the weld does not chill off quickly enough to cause it in the first place.

Generally the part involved is relatively small but they could be part of a much larger item. I was thinking that the welded area was picking up the carbon from the gas(C25). I have not tried to anneal the part, nor a have I tried to preheating the part. Most of the material I have worked with was cooled roll steel which I would not think would be a hardenable steel.

Often the work involves repairing worn out holes where the idea is to fill the hole and re-drill it.

Thanks for you inputs

Ken

Gas and TiG welding heat the panel slowly, then it takes a lot longer to cool it down, This is an annealing process. But MIG heats up the metal quickly and cools a lot faster, which I think is a hardening process.

Now there are few wires like ESAB Easy Grind that helps make a softer weld, by changing the alloy, but it's still not as soft of a weld which you get gas or TIG welding process.

Thanks for the input

Ken