TIG problem - Porosity!

[Echidna]

I recently faced a problem with my TIG welding, a problem that i never had before. I get posority out of my TIG welding with no apparent reason.
My current setup is:
Pure Argon gas, a Chinese but very good DC TIG welding machine, 1/16" tungsten (red), 1/16" and 3/32" ER70S-6 filler rods.

Here is what i got:

I decided to grind off the affected arear and start again:
You can see that posority has gone quite deep into the base metal!

I tried again, and the result was better but still porosity is there. It like the area is infected...

In other arear the weld is OK, weird...

Any ideas? Thanks a lot!

 

[wyn]

Maybe the bolt you are using to hold the parts together has oil on the threads and this is burning off with the heat, causing the trouble.

 

[Echidna]

I thought about it but the problem occurs not only on this area, but rather randomly.
Look here, it occurs randomly...

 

[inchpincher]

I'd say there might be an impurity in the boss you're welding which may in turn have contaminated the tungsten. I'd been having similar problems that I eventually traced to an air leak in the flex head of my torch...

 

[backpurge]

I would try getting more filler wire into the joint and keeping the weld size down

 

[mike os]

contaminated wire?

 

[chevy2]

I'd say there might be an impurity in the boss you're welding which may in turn have contaminated the tungsten. I'd been having similar problems that I eventually traced to an air leak in the flex head of my torch...

Also had a similar problem,
Split hose just before the torch,
took ages to diagnose, kept upping the gas flow,
sometimes porous sometimes not? depending on what angle the torch was at was whether the leak occured,
taped the hose temp and the problem went...new torch purchased.

 

[Echidna]

Also had a similar problem,
Split hose just before the torch,
took ages to diagnose, kept upping the gas flow,
sometimes porous sometimes not? depending on what angle the torch was at was whether the leak occured,
taped the hose temp and the problem went...new torch purchased.

That's exactly what i get.
Sometimes porous, sometimes not.
I don't even think it's a case of bad quality steel as i have tack welded some parts together with absolutely no probs, then returned these days and i consistently get bubbles!
I will check my torch tomorrow and see what i get...

 

[Welderpaul]

One or more of the following:
1. Lack of gas
2. Too much gas
3. Contaminated material/filler wire
4. Leaking set up/hoses etc
5. Draft/breeze blowing shielding gas away
6. Contaminated tungsten
7. Err..

 

[Drains]

I reckon No 4 is your thing too.

Nice list though Paul. Well done!

 

[Lawnmowerboy]

Was it leaded steel do you know?

 

[Echidna]

I don't know the steel grade, but bear in mind that this problem occurs on simple mild steel too. So, it's not the steel grade of the boss that caused the prob.

 

[inchpincher]

This is where mine was leaking btw, it wasn't as obvious as it looks once I'd pulled the head out of the torch body...

Video

 

[Echidna]

This is where mine was leaking btw, it wasn't as obvious as it looks once I'd pulled the head out of the torch body...

Video

And what the solution was? You replaced the torch or repaired it some way?

 

[inchpincher]

Bought a new flex torch head, I think they're about £17. On gas cooled torches, especially with the flex heads they perish with high amp heat cycles (and a bit of newbie exuberant bending). This is my second replacement.

 

[langy]

Bought a new flex torch head, I think they're about £17. On gas cooled torches, especially with the flex heads they perish with high amp heat cycles (and a bit of newbie exuberant bending). This is my second replacement.

Everybody says flexys don't last long but I had mine 6 years now, still working perfectly.

I agree with the others, you have a leak or bad seal somewhere

 

[Echidna]

Can i put some soapy water on certain places of the torch and then let the gas flow to see if any bubbles build up? Maybe this is dangerous, some soapy water get inside any possible leaks?

Where can i buy this 17 pounds flexy torch? Thanks!

 

[inchpincher]

http://www.weldequip.com/tig-torch-heads.htm or buy one from wherever Langy got his!

I used soapy water, there is proper leak detector fluid available but it's pricey.

 

[Echidna]

Thanks for the link!
This torch is only for using it with a pedal?
I ask because it does not seem to have a button.

 

[Echidna]

I've just made a test with soapy water and there is indeed a leak at where the backcap meets the torch body!
It's not a severe thing but there's certainly a leak.
Do you think this will cause all the problems?