Multimatic 200 Post Flow not shutting off

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I know the 200 post flow is not adjustable. Just having an issue with it staying on and just running argon after I end a bead, it happens after every 20 or so beads. To stop it I'll have to arc it on the table and then it will stop. I'm assuming this is circuitry not a solenoid or anything mechanical? Any ideas?
Love my machine and not usually a problem unless my shop is noisy then I could be wasting a heck of a lot of argon... Thanks for any replies

[Aeronca41]

Is it still under Warranty? If so, I'd take it in.
It's possible the solenoid valve is sticking every so often, but if under warranty, I wouldn't mess with it. I suppose you could dry a light tap on the valve when the gas keeps flowing and see if it closes. Could be some debris in there.

[mongobird]

I would be suspicious of some dirt in the solenoid. But if under warranty, I would get it in.

The post flow is not adjustable, but does vary with weld current. In other words it is longer when welding with a higher current.

[Olivero]

Yup, sounds like a sticky solenoid. Or your pedals/trigger is getting stuck but then its not post flow, its still trying to arc which I am guessing is why you said its post flow, but thought I would mention it either way. If its under warranty, definetley take it in don't mess with it despite how good you may be, it won't be worth it if something goes wrong. Plus, they will just replace it, no one but the end users tend to want to deal with the problem with the part, than just replace it as its easier.

[xryan]

99.95% solenoid sticking. I learned that too after a while the hard way, KEEP A CAP ON. I actually have QC fittings on both as it is my quick and portable machine, I leave caps on both ports when not in use, pop one off and quick connect the shield gas. Good to go and won't have to open it up again to clean out the solenoid.

[[email protected]]

Thanks for all the responses! And thank you xryan for mentioning keeping the caps on! I do keep them capped but not everyone would know this, and with so much flap disc grinding in the shop they would inevitably get loaded with metal dust. I think my warranty may be over but will check.