Mig, Gas solenoid.

[Rustydog2010]

We have a Cebora Mig welder, lately I have noticed that the gas flow is almost constant. You start the machine up, start welding and when you release the trigger you can hear the gas still flowing. Sometimes the gas is a full flow or like a minimal leak. This suggests to me that it maybe a sticky solenoid.

How do you combat it? A bit of WD40 or something?

Pictures.



Should the silver piece move freely, or not?
Any help is appreciated!

Jeremy.

 

[fowler]

the blokes at mining workshop where i work spray a CO2 mix into their electric rattle guns and into anything electric

try and find some

or just use crc
i dont really know about the workings of a mig but my guess is u dont want any crc in the gass flow

 

[The Mechtician]

Should the silver piece move freely, or not?

The silver piece you're describing is just a tube that holds the spring & solenoid core (which has a sealing face on one end that mates with the valve seat). Sometimes they're pressed in, sometimes they thread in. If the spring is saggy from thousands of hours of use, try shimming it with a couple washers. The valve seat may be pounded out of it as well. WD 40 works good for cleaning up the seat & lubricating the solenoid core in the spring tube. Otherwise, those solenoids are so cheaply made that I simply replace them.

Before you junk the solenoid though, check your regulator/flowmeter. Most welding regs are non-adjustable and supply gas at 50 psi. Install a gauge downstream of the flowmeter to see what the pressure is. I had the exact same problem you describe, took the solenoid apart and found nothing, checked the line pressure and it was 180 psi!! New reg fixed the problem Good luck!

 

[Rustydog2010]

Cheers for the reply.

I cant seem to get the silver part out. We have this kind of regulator, it seems in good condition and is only a few years old, that and the welder isn't used that often and cant be over 3 years old.

Im guessing this is a adjustable one?

Was the 180psi dislodging the valve from the seat or something in your case?

Jeremy.

 

[The Mechtician]

I can't say for sure if that reg is adjustable, but if you say it's only a few years old it should be ok. In my case the solenoid would never really shut off because the excessive gas pressure just blew the valve open. Did you try hosing some WD 40 into the valve?