Problem with inverter TIG welder

[agent007]

Hello,

I´m new in here and I desperately need help!

My setup:
usual inverter, cheap one. Max. 80amps.
WP9V TIG torch, air cooled, max 150A.
(Scratch start)

Problem:

The problem started when I had tigged a little with my new setup. All went well and the welds looked nice, until it just started to splatter and nice welds said goodbye. It also seems that the arc is just like fading away, not centered or focused on one spot. I thought that I contaminated the tungsten, but after sharpening it didn't make a difference when welding. I used 1,6mm tungsten on 1,5mm mild steel sheet. I'm using pure argon and giving it to the torch about 6lpm.

So I ripped my inverter apart and looked if anything is cooked there. But everything seemed to be OK. Crappy thing about this is that my electrical skills end here and I don't know what to check next?

So, anybody who knows anything about my problem - offer me some solutions or fault finding techniques!

Sorry for my bad English.
Appreciate all the help, Siim.

 

[GeorgeB]

Welcome to the forum. I'm sorry to hear about your good welds going downhill for some reason. Are you sure that all factors have been held equal in between the set ups used for the good welds and the bad welds? Could the Argon have run out, or could it be anything simple like that?

I have a similar, low cost DC inverter which I've only used for MMA (arc) welding so far. I hope it doesn't fail before I get a chance to try TIG. Did you use your inverter for MMA welding with a stick before? It might be worth trying stick welding to test the basic capacity of the unit to provide an arc.

As for diagnosing an electronic problem with a DC inverter, I should think that would require quite high level knowledge unless you get lucky by spotting something simple like a blown fuse, a leaking capacitor or black marks around some other component. If my inverter ever stops, I'm sorry to say I'd fear the worst! It was low cost so I'd view it as 'disposable'.

 

[agent007]

Argon cant be out. I just refilled the tank.

I also tried to weld in MMA "mode" . It worked the same as it used to.

I have thought myself crazy over here - why the arc faids away.
I have no winds in my garage, tried to turn up the gas flow, checked for any major gas leaks. Nothing. What can I check next?

 

[GeorgeB]

I also tried to weld in MMA "mode" . It worked the same as it used to.

If the arc doesn't fade away in MMA mode, I would think that sounds like quite good news in terms of the inverter probably beng OK. I can't see how TIG mode is much different in terms of what the electronics are delivering. Could the TIG torch or supply cable be damaged in some way, not that I know much about TIG torches? Do you have a good earth connection?

 

[Jake SS]

Can you get another tig torch to try? To eliminate that for starters.
If it works OK on stick then it should not be a huge problem.
When you say the arc fades do you mean that it welds OK at say 60 amps then reduces to 0, over what time period?

 

[agent007]

Can you get another tig torch to try? To eliminate that for starters.
If it works OK on stick then it should not be a huge problem.
When you say the arc fades do you mean that it welds OK at say 60 amps then reduces to 0, over what time period?

1sec.

 

[eddie49]

When you change from MMA mode to TIG, is it just a case of replacing the electrode holder with the torch, or does your inverter also have an "MMA/TIG" switch on the control panel ?
If it does not, then it sounds like there is a bad connection in the torch assembly, along the path from the Dinse socket to the tungsten, which heats up and becomes a high resistance as you try to weld.

 

[agent007]

When you change from MMA mode to TIG, is it just a case of replacing the electrode holder with the torch, or does your inverter also have an "MMA/TIG" switch on the control panel ?
If it does not, then it sounds like there is a bad connection in the torch assembly, along the path from the Dinse socket to the tungsten, which heats up and becomes a high resistance as you try to weld.

My machine doesnt have any switches for Tig/MMA mode, I just change the cables. But is there something that I should check first when parting out the torch?

 

[eddie49]

If possible, try another torch. Otherwise, an ohmmeter may show that the torch has a high resistance. I have never taken a TIG torch to pieces, so I don't know which part is likely to fail.

 

[madkayaker]

from what i have read the problem might be due to the heat so measure cold and maybe warm the torch up a bit then re measure (borrow the oven when the missus is out) if it is a connection look for arching and/ or dirty connections

 

[wallopadonkey]

are you putting the torch into the - connection and the earth (ground) clamp into the positive? as you should have it the opposite way to mma welding.

is the dinse connector on the inverter nice and tight when turned ?

 

[agent007]

Yes it tight, but I will defenetly check all the connections, including the dins connection. Thanks for the help. Ill let you guys know how I did, or what I found!

Thanks again.

 

[Drains]

Hi agent007!

I notice you say it can't be the gas because you've just had the bottle refilled. So before it was refilled, how was your welding? Did it change after you got the new gas?

Contaminated or incorrect refills are a possibility.

Cheers

Si

 

[agent007]

This bottle of Argon is new to me.
Now, I have checked all the the leaks in the system. Also found two leaks from there. I fixed it up, but there is no change in the welding.
Tried also changing torches, even this did not help! So Im thinking here that my freaking low-cost inverter has some problems.
I have taken it apart and looked inside, but didnt notice any failures or "smoked things". But, Im really sure that something is wrong with the power source - inverter.

Also this cant be a filler problem when its not even working when Im welding WITHOUT the filler!

So, What to look or what to do?

Thanks for all the help.
Siim.

 

[irondarren]

Tig does like nice clean metal, if its not nice an clean it just doesnt like it. Im sure that bit of advice is fat to obvious.
Im not sure this would help either but try and do a little tig run and post a pic of it here on the forum, it could help.

 

[agent007]

Okey, I also thought that would help. Maybe I can make a movie, I´ll see what I can do!