MIG welders, I need some input.

[tlmartin84]

I've been MIG welding for the last 15-20 years. I have went through hundreds of pounds of wire and this has me stumped.

I just switched out tanks and immediately noticed it. Upon initial startup I get popping, spatter and a pourous weld, then it smooths right.....any ideas?

I've tried different amperages, different speeds, and different metals. It does it consistently. It is almost like I am not getting gas the first split second and then it kicks in?

BTW I am running a Hobart 210MVP with ER70S-6 HOBART .030 wire.

 

[Bigblue&Goldie]

Bad bottle of gas?

 

[RustyJunk]

You won't get gas when you first pull the trigger unless you have a pre-flow gas setting on your mig like many tig machines have had for years. Most of the lower priced migs dont have it but I'm seeing it a lot more on many of the new migs. You can purge the line if you shut off the feeder for a few seconds and pull the trigger.

 

[tlmartin84]

Bad bottle of gas?

That was my initial thought, but why does it smooth out?

 

[tlmartin84]

You won't get gas when you first pull the trigger unless you have a pre-flow gas setting on your mig like many tig machines have had for years. Most of the lower priced migs dont have it but I'm seeing it a lot more on many of the new migs. You can purge the line if you shut off the feeder for a few seconds and pull the trigger.

I've had this machine for 3 years, this is the first time I've had this issue.

It doesn't matter if I purge it...first squeeze after purging it and it spatters. Then I can run a nice bead. If I stop and restart it does it again, then takes off smooth.

 

[dr_clyde]

Can you confirm what gas you are using? Put a different cylinder on and see if it goes away.

If you have the wrong gas mix, arc starts can be a bit fussier, and cause some problems.

If the problem started when you changed cylinders, change them again and see if that fixes it.

 

[tlmartin84]

It's 75/25

 

[tlmartin84]

Could it be a contact issue?

Maybe just coincidence it started around the same time?

 

[willymakeit]

How clean or what condition is your liner or feed rollers?

 

[Bigblue&Goldie]

I had a similar issue that I chased for far too long...... I finally tore the machine down just to discover that I had an .030 tip when I was using .035 wire. I had bought these tips years before and never had an issue. Sure enough, I went through the remaining pack and there was another .030 mixed in. Thanks Miller! Very frustrating.

 

[dr_clyde]

Just because the cylinder says 75/25 doesn't mean it is. The gas suppliers still make mistakes occasionally. I still think you need to swap to a different cylinder to rule out gas issues.

In my experience as soon as you change something and problems arise, the thing you changed is the cause.

 

[great white tj]

Do you have a fan blowing near your weld area ?

 

[Biscuit1979]

Check tips and check your ground

 

[scooby074]

Put your ear to the gun, pull the trigger, and listen. You should hear the woosh of gas right away, if not, check your gas solenoid

 

[steel 35]

Just oil the little wipers in front of the drive wheels?
Or give it a good hot dip?

 

[Zeke]

That was my initial thought, but why does it smooth out?

No one mentioned checking out your flow meter. Or a breech in your cable allowing ambient air in between welds.

 

[matt_i]

No one mentioned checking out your flow meter. Or a breech in your cable allowing ambient air in between welds.

You called it and I had the same thought, perhaps the inrush of gas from the initial pressure spike of cracking a fresh bottle did something to the gas regulator.

I'd open it up a couple of turns, and send it back down to where you had it before and see if that helps out.

 

[f150skidoo]

I was having similar issues with my old HH 190 and I couldn't figure what the issue was but I ended up taking the cover off the machine to check out the guts and my gas line had a bit of kink in it. the jam nut on the gas port was just loose enough when you would change tanks out and move around the regulator/ supply line it would start to kink the internal line restricting the gas.

 

[bdbecker]

Put your ear to the gun, pull the trigger, and listen. You should hear the woosh of gas right away, if not, check your gas solenoid

No one mentioned checking out your flow meter. Or a breech in your cable allowing ambient air in between welds.

I was having similar issues... and my gas line had a bit of kink in it...

I suspect the issue lies here as well.

If its an ambient air leak, the issue wouldn't really be noticeable if the welds are done in quick succession (only a few seconds between welds), but would be noticed if you waited longer between welds (time would depend on the severity of the leak).

If it doesn't seem to be related to the time between welds, I'd be looking to the flow meter/regulator or the solenoid. Do you know someone who has a flow meter/regulator that you know is good that you could borrow to eliminate that variable?

 

[tlmartin84]

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Okay there are some welds I laid down today.

Adjustments:

New tip.
New shield.
Opened regulator fully open and readjusted.

I checked for any signs of leaks and nothing. I usually run about 20-30 psi. If I crank it up to about 50psi the problem seems to lessen but it is still there.

As you guys have stated, the longer it sits the worse it is. HOW DO I FIND AN AMBIENT LEAK?

 

[Bretny]

Soap and water.

 

[sberry]

Kids bubble soap or Dawn seems to bubble better than others.

 

[sweetk30]

i had a machine brand new out of the box the gas would flow but most of the time never come out the tip / nozzle .

i tore it apart and found the gun liner end thats crimped on for the gas to be directed down was no good and the liner seperated so most of the gas was leaking out every place but the nozzle area .

i got a new liner and installed it and still working to this day great after 5 years .