Plug weld with mig

[rbh]

So I attempted to plug weld a stainless piano hinge to a piece of mild steel???
drilled a hole every 2-3 inches across the hinge, clamped it down, applied ground to steel and started to fill in the holes.
well it looks, OK, but what are the odds I melted the stainless instead off filling it with the mig's steel wire???
(I got flat pancakes for beads, And I was expecting small mountains of metal)

And to add, I forgot to turn the gas on.

 

[dingbat]

Re: Plug weld with mig

You can weld mild steel with stainless wire but you can not weld stainless with mild steel.

Welding SS with mild steel wire w/ no gas = :redface:

 

[rbh]

Re: Plug weld with mig

You can weld mild steel with stainless wire but you can not weld stainless with mild steel.

Welding SS with mild steel wire w/ no gas = :redface:

Just trying to figure out if I plug welded the piano hinge right or wrong.
From what I know, you can't weld ss to any steel, so you have a couple of choices, rivet, bolt, drill hole through stainless and do a plug weld.
just teaching my self to weld.
Just keep listening for the sound of frying bacon.

 

[dingbat]

Re: Plug weld with mig

Just trying to figure out if I plug welded the piano hinge right or wrong.
From what I know, you can't weld ss to any steel, so you have a couple of choices, rivet, bolt, drill hole through stainless and do a plug weld.
just teaching my self to weld.
Just keep listening for the sound of frying bacon.

You can weld SS to mild steel. Done it may times in non-critical applications. Use 309 stainless as your filler metal.

The down side is that the weld will be brittle due to the formation chromium carbide in the bead. I wouldn't count it retaining any structutal integerty.

Not sure what you mean by "done right". When plug welding, you run a bead of weld around the inside of the hole to connect the two materials. If the hole is large enough, you may end up with no weld in the center of the hole at all. Any material that is not in direct contact with both materials is a waste of time and effort. Filling in the center of the hole is for aesthetics only

 

[rbh]

Re: Plug weld with mig

My thoughts on this is that the mig wire was contact the steel and to build up in the SS hole forming a mushroom, sort of a rivet???

close or out to lunch?