Trouble welding stainless

[Akane]

Hi hotrodder,

I have regrind the tungsten, change back to #5 cup
This time I got as close to the parent material as possible, approx 2mm, arc still jumps, post flow is set to 5 seconds.

Here's the tungsten afterwards:


Here's the material:




Thanks!

 

[hotrodder]

The tungsten should remain clean, shiney and tungsten coloured so you've got a gas leak that's drawing in air and oxidising the tungsten or (less likely given the picture of an argon cylinder) dodgy gas or an argon/CO2 mix.
Probably me but that was about the longest 2mm i've ever seen

 

[Akane]

I just went to check the lines inside the welder like you've suggested.
Everything is good, no obvious leaks, used the check gas function on my welder, good amount of gas coming out, blocked the torch with my hand, no leaks could be heard.
Called my gas supplier for this bottle, they said no reported bad gas.

I'll try new gas shortly, thanks for all your help.

 

[wheresmejumper]

You really need some leak detector fluid or something similar to check for leaks.
listening is no good

 

[BrokenBiker]

if you cant get leak detector soapy water will do for pipe joints but beware of electrics if checking inside the machine

 

[Akane]

Hmmm I'll leave that to last, sounds something that's very last resort, it's a 200 AMP AC/DC IGBT Machine that doesn't have a lot of room between the gas pipe and electronics, I don't want to break it just yet. Gas next then I'll explore the soapy water option, cheers.

 

[BrokenBiker]

Hmmm I'll leave that to last, sounds something that's very last resort, it's a 200 AMP AC/DC IGBT Machine that doesn't have a lot of room between the gas pipe and electronics, I don't want to break it just yet. Gas next then I'll explore the soapy water option, cheers.

I have slid a bit of cereal box between the gas pipes and the electrics in my mig to get some soapy water on there to find a leak. will take a while for it to soak through the card and plenty of time to check for bubbles.

 

[wheresmejumper]

Plain old spit will do if your glands are up to it.
be prepared though, a normal setup will have around ten joints to check

 

[richp123]

You need to change the gas you are using because straight Argon on stainless is a pig at best, will check tomorrow at work to see what we switched to after much swearing and spatter everywhere.

 

[Paul.]

You need to change the gas you are using because straight Argon on stainless is a pig at best, will check tomorrow at work to see what we switched to after much swearing and spatter everywhere.

I think you are getting mig and tig confused, pure argon and tig will weld just about anything, there are other options such as helium and argon helium mixes but for the most part are not necessary,

 

[biffa]

As others said you've got a leak some where. Posting a few pictures of you torch may help identify a problem, as well that sheet doesn't look like stainless to me.

You need to change the gas you are using because straight Argon on stainless is a pig at best, will check tomorrow at work to see what we switched to after much swearing and spatter everywhere.

Ignore that straight argon on stainless is the only reasonable gas you can use for hobby tig welding

 

[BrokenBiker]

You need to change the gas you are using because straight Argon on stainless is a pig at best, will check tomorrow at work to see what we switched to after much swearing and spatter everywhere.

if you try running co2 through a tig torch you will go through a lot of tungstens

 

[richp123]

Paul, apologies....You are quite right, I did indeed mix up the MIG and TIG forum posts Akane, disregard everything I said in my earlier post.

Akane, I've been using TIG for several years and have never seen the problem you are getting even when the tungsten tip is as far out as shown on your photograph - If it's the right gas at the right pressure with no air leaks in the system and it's clean stainless steel that you are TIG welding, the only thing I can think of is whether you have a cooling fan nearby that is blowing air over the work surface so reducing the Argon shield over the weld surface?

 

[BrokenBiker]

just out of interest what rods are you using?

 

[Tigman]

Akane give us a picture of your machine settings , a good picture of all the bells and whistles just to see what you have switched on and off , might be a setting wrong somewhere !

 

[Akane]

I got my bottle refilled by another supplier, purged and filled right in front of me, still the same issue.
1) I have noticed that if I pumped the flow all the way up to 20LPH and run a weld without a filler material, it "seems" to be slightly better, no more jumping of the arc everywhere, but still getting frosting.

2) once I add filler material, black soot marks are there, material balls up.

20LPH without filler:





Here's a picture of the machine setup, it doesn't really tell you much unless you go through the dials.




I have it set at preflow 2 seconds, 30 AMP start, ramp up to 50 Amps, ramp down to 20 amps, post flow 5 seconds.

Is it possible a broken TIG machine will give me grief?

I'll do the bubble test tomorrow.

 

[Lawnmowerboy]

A test we use at work is put a balloon over the ceramic and press button and fill with gas as Mugh as poss then take it off a nd burb throught the balloon with a match. If there's an air leak it will stay lit. Otherwise it will go out

 

[Wallace]

How are you measuring the gas flow?

 

[Akane]

With an Argon flow regulator meter, looks a lot like this one: http://www.alibaba.com/product-detail/CO2-ARGON-GAS-REGULATOR-with-flow_340932448.html

I've thought about grinder contamination, so I just took a brand new tungsten out of the pack, no grinding, and tried to do a bead, same deal, so it's not the grinder.

 

[hotrodder]

Is it possible a broken TIG machine will give me grief?

Yes but not the problems you're currently having, at least the two big ones...
1) toasted tungstens. The gas test function and the vids confirm that the gas solenoid is working properly- can hear the gas start before the arc is initiated and shut off after the post flow time. That leaves the wrong gas (even less likely now after swapping it out), a leak either from a dodgy connection/pinhole somewhere or from an incorrectly assembled torch- collet in backwards is surprisingly common... http://www.mig-welding.co.uk/forum/threads/my-first-goes-at-tig-welding.38690/page-2#post-428470
Too much gas flow is typically worse than not enough however that generally only effects the material being welded not the tungsten. If the tungsten is being toasted and the post flow is working it's something fundamental like a leak or the pure argon isn't pure argon
2) Already been mentioned several times but from the last pic posted i'm 99.99% sure that some of your stainless is actually aluminium. It's kinda irrelevant when the tungsten is being toasted but using the wrong filler and/or polarity for the material ain't gonna help once the gas issue has been fixed...

Colour/texture looks a lot more like ally than stainless but pics can kinda lie, the giveaway is the area highlighted with the red line that's boarding the 'weld'. That's typically what ally looks like when trying to weld it with DCEN, a wrinkly skin where the ally melted underneath a skin of aluminium oxide. The black mess is typical of a gas shielding problem and happens with AC too. The first pic in post #19 looks more like the result of stainless with a giant gas problem, similar black crusty mess boardered with heat discolouration (something that doesn't happen with ally) where it got hot but didn't melt

It's pointless trying to run welds with or without filler until the gas problem is fixed. The 'spot weld test' is all that's needed to check shielding quality both from the tungstens POV and the materials... http://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/page-2#post-301703