tig crater

[Piero]

Don't know if I spelt it right (crater) but can anyone e plain what one is (hole in metal )

I was just getting some torch time in with the intention of stacking some bead.
Silly so and so forgot to turn the gas on.
Tungsten burnt away a little and a hole/crater appeared.
Grate I thought, will try and see how to repair this if it ever happened in real terms.
Ground tungsten cleaned work piece with stainless steel brush and got back to welding
Try as I may I couldn't get the crater to close properly on the steel I was welding.

 

[Drains]

You should grind it out. Trying to repair it is normally a waste of time - even if you cover it over there'll still be porosity. There will be either a pocket of air/gas which stays in place and contaminates the steel, or oxidisation which can't be burned away. Sometimes with good de-oxidising filler rods, you can get away with it, but it's not the right thing to do and as I say, you're probably covering over porosity.

 

[Piero]

So what exactly is it????
Just interested that's all
Want to learn :-)

 

[Country Joe]

Contaminated or oxidised steel. With a crater!
Sometimes you can stop the crater by leaving the shielding gas covering the end of the weld, along with not whipping the torch away too quickly, even a dab of extra filler helps - but you'd have to be using gas for that to work!
CJ

 

[shenion]

You did not say what type of metal.

If aluminum, it would be covered with aluminum oxide. That is very hard and melts at a very high temperature. Can really only be ground away.

 

[Country Joe]

You did not say what type of metal.

Oh, you're right! I just assumed stainless!

Oi, Piero - what are you working with?

CJ

 

[Piero]

Sorry cj don't understand your question.

Are we talking what metal????

If so I was stacking some beads on a new bit of scrap Irish J.
Was working in dc with a red tip tungsten. BUT forgot to turn on the gas .
Pure argon.
I am only curious about why the crater would not fill up after I turned on the gas.
Tig welding is quite new to me

 

[Country Joe]

Sorry cj don't understand your question.

Are we talking what metal????

Yes, I was just asking what material you're working with.

It's most likely that unless all the oxidised mess is ground out completely, (just as Mr. Drains says) it won't take a weld very well at all.

Not sure what "Irish j" is though!

You did mention going over it with a wire brush, but I'd expect it to need completely removing before trying to put another bead over it.
All the Best,
CJ

 

[Paul.]

CJ was asking whether you were welding stainless or mild steel, the answer is the same though, by forgetting to use gas you have oxidised the weld pool, that oxidation is very difficult if not impossible to boil out out, the de oxidising properties of the filler rod can help, hence the earlier comment from drains,
the best de oxidiser in these situations though is a grinder, or carbide burr in a die grinder

 

[Alfaman]

If so I was stacking some beads on a new bit of scrap Irish J.

RSJ? Just a guess...

 

[Sub-arc]

Slander I tells ya....!

 

[Piero]

RSJ and as some call it Irish J LOL