First off, I'm just a hobby welder (mostly light stuff like bicycle frames) and have used my machine very little in the last few years.
L-Tec Heliarc 250 HF Plus about 20 years old Heliarc HW-17 gas cooled torch Foot pedal control
I think I'm suddenly getting a lot of air in my argon flow. By suddenly I mean one minute everything is fine and the next minute all I'm getting is s puttering, a sort of corona between the cup and the work, a melted gas lens screen and a blackened electrode.
This seems similar to what happened when I tried to weld after having to di sconnect the hose from my flowmeter to the welder last year. It didn't occ ur to me I'd have to purge air from the hose before welding again. This is much worse than when I had a bad O-ring in the torch cap.
I was TIG welding some 0.065? wall rectangular steel tubing. I laid down an inch of bead just fine. Then I skipped forward an inch and tried to sta rt another bead. Nothing had been changed.
There is no leak between the flowmeter & the welder. When I blow into a ne w cup there doesn't seem to be any leak between the torch and the machine.
I assume there is a valve inside the machine that has failed. Does that ma ke sense? Can replacement parts be found or can the valve be repaired?
The welder is in my basement & I had to hire piano movers to get it there. So bringing the machine in for service isn't Plan A.
I've been away from this forum for several years. Good to see Ernie's stil l here.