Welding Tips and Tricks

Hello.New member here.Been following Jodys videos for several years and learned welding mostly from them.I dont primaririly work as a welder but I do weld with tig from time to time at work and have become quite good at it.

I bought a ewm tetrix ac/dc tig machine for my own use a couple of years ago,its a not so well known german brand that makes quality german made machines in the price range of lincoln,kemppi,esab etc.Not some cheap chinese made unit.
I have a dual flow meter with ball flow meters.

When i first got the unit i tested it at my work place and their argon bottles and it worked beautifully,much better than the telwin and selco units we have there.When i got the machine home i bought a bottle of argon and it was almost unweldable,crazy amount of porosity with black welds and spark flying.I then pressure tested and searched for leaks with window cleaner(great for finding small leaks),found both hose connections inside the machine leaking sligthly and one of the tig torches was leaking as well at the hose connection,repaired these but the weld quality was still horrible.

Next i got the shop that i bought the bottle to exchange bottles as i suspected the argon was bad,got a new bottle and the welding improved alot,but i still was not getting good coverage(silver welds),as the bottle was starting to get empty the weld quality dropped as well,alot more oxidation.This new bottle also brought the problem of loosing gas once the bottle valve was shut,it would drop from 210bar to zero in 5 minutes.The gas would come out of the torch,plugging the hose connection at the machine would keep the pressure until next day.

Again suspicious of gas issues i took the machine back to work,hook it up to the gas bottle there using my own regulator and flow meter,welds beautifully and only dropped 10 bars overnight with the bottle valve closed.So great,i have bad gas in my own gas bottle again.This time not trusting shop 1 anymore due to getting bad gas 2 times in a row,i get the same bottle refilled at another reputable shop which do refills at another location.I get the bottle back and its still welds the same and drops the line pressure in 10 minutes again.

I have tried 3 different tig torches and hose connections,replaced cheap chinese gas lenses and collets to esab(this did improve things).Tested different flow rates and cups sizes up to 12.Leak tested everything from the bottle to the torch.Im at a total loss,i have wasted 2 bottles of argon trying to find the culprit.You can weld with it,but stainless welds will be rose coloured at best with black soot next to the weld,aluminium will have oxidatition on the welds,not to mention the weld pool does not flow as it should since there is crap floating around.

One thing i have notized is that if i heat up the shop to normal room temperature,then the solenoid valve will usually seal and keep line pressure overnight,if i weld in outside temps then it will leak the pressure fast in like 10 minutes,its like the solenoid valve wont seal at colder temps,but im not sure if this is related to my bad gas coverage.

I would appreciate if anyone had any ideas what could be the culprit,i just down know where to look anymore.

Try this. Get a cheap brand new tig torch that has a valve on it (if you don't already have one). Run it straight to the argon tank, not through your welder, which by the way is a pretty cool machine (I almost bought one myself to import into the USA!). Use ONLY regular, standard non-gas lens consumables with the correct back-cap and Teflon insulator. Make sure the collet is inserted correctly (yiud be surprised how many put the collet in backwards. Then weld. This will tell us once and for all if your argon is good or bad. Once you kniqw this, then you scratch it off the list. A systematic approach is best, IMO.

In the same vein as Oscars suggestion, can you just bypass the solenoid with a jumper hose between the bottle hose and torch hose and use a pair of long nosed vise grips, with fuel hose on the jaws, as the "valve" on the jumper hose.

Set everything up and get someone to release the clamp or even do it yourself, the gas you lose would be minimal and you'd get an answer.

Is the torch the original that came with the machine ? You don't mention what brands you have tried, but for good quality consumables, this outfit is good . https://www.ewsgmbh.com/home.html

There is some real crap on the market there.

Based on everything you said, I would suspect the solenoid first and foremost. Especially since you noted that it has problems intermittently. The hardest thing about troubleshooting anything is chasing an intermittent problem.

Can you hook your tank to the welder at work? This would isolate tank and welder.

Thank you for all your replies.

Trying with a torch with a separate valve is a good idea,dont have one but could try.I have used double back caps on the torches to plug the torch end when searching for leaks.

I have a chinese air cooled 4mlong 9, a chinese 8m water cooled 9 as well as original ewm 4m air cooled 9,same problem with all torches.All have esab collets and gas lenses,the ewm torch has a bit damaged torch head so have not been using lately for testing

I intially found a large leak on the chinese 4m torch which has since been repaired and tested leak free.I also found both hose connections inside the machine with small leaks,ewm uses a hard plastic hose and oetiker clamps,i replaced the clamps and tested that they were no longer leaking.Not really fond of ewm hose material and would like to replace it along with the solenoid valve.Problem is this machine with all its features is full of circuit boards and there is really no space inside,i think to replace the hose would require to remove circuit boards and such.

I have tried the welder at bottles at work and got silver welds,although some welds were a bit iffy but It could be prep work/material as well.Also all the gas leaking issues were gone at work,the temperature there is very warm like 25C.

Are the solenoid valves repairable or replace only?I have repaired industrial solenoid valves but no idea on these small thingys,usually just a bad o-ring or such that goes bad.The leaking inc cold temperatures could have to do something with seals hardening with temperature.If i close the gas regulating valve the bottle pressure will stay indefinately so that part is definately good.

I will try to do some troublesearching again after christmas.Im quite sure the solenoid valve is the culprit for the leaking,but im not sure if that is the cause for the oxidation of welds.

I had a solenoid issue with one of my machines. It would always fully open but occasionally would not close following weld termination, even after post flow time. A little tap with anything and it would close and work properly for a while and then act up again until it got a little tap. Replaced the solenoid and all is good. This happened some time back and I'm not sure what time of the year this happened and I don't remember what the temps were in the shop when I had the issues .. sorry, I'm old.
gramps

malyb@live.com wrote:Are the solenoid valves repairable or replace only?I have repaired industrial solenoid valves but no idea on these small thingys,usually just a bad o-ring or such that goes bad.The leaking inc cold temperatures could have to do something with seals hardening with temperature.If i close the gas regulating valve the bottle pressure will stay indefinately so that part is definately good.

My experience is that they are mostly meant to be replaced. However, they are slightly serviceable for o-ring replacements, solder joint repairs, spring tweaking, etc. But I doubt that would solve your problem if the solenoid is indeed the culprit. I would suspect a faulty coil or a poorly machined part in the solenoid if it is bad.

I also believe that you're right, Spartan. I took the old solenoid apart and found the piston and bore highly polished. I would also imagine that a small piece of dirt or some kind of contaminate would cause problems. OR IF the o ring should be lubricated to allow smoooooooth operation of the piston. A very small piece of something that doesn't belong in there would be like a speck of dirt in your eye feeling like a Greyhound bus.
BUT I never had the solenoid with partial operation. It was ALL or NOTHING. Therefore, I'm leaning to multiple problems...OP said he found "leaks" and repaired them. OP said his machine worked better with work place bottle. Perhaps some form of contaminate already went thru the solenoid. Perhaps "his" bottle has bad seat for regulator.
Just for instance suggestions.

I had a little time fiddling with it today,did not have garage clothing on today and spending christmas so was not going to pull anything apart but a quick leak finding.

1.I pushed the electrode all the way back in and then i put a rubber glove finger onto the cup,had to stretch it onto so should be sealed,back cap screwed all the way in.Turning the argon on the bottle and closing,im loosing pressure quite fast(140bar/10min) but finger is not inflating,so either the solenoid valve is not leaking or i have a big leak after the solenoid.

2.Next i plugged the torch using 2 pieces of flat rubber and a welding clamp.Next gas on,machine on and push the pedal to flow argon,after initial gas flow to pressurize the whole torch etc i could not get the ball to move again when pushing the pedal even after waiting a few minutes,so definately not that big of a leak.

3.If i closed the needle valve to adjust flow at the regulator the pressure at the reg vill stay indefinately after bottle valve has been closed,so the reg portion should be good.

I sent a inguiry for a new solenoid,think i will also source new hoses and clamps once at it.Any suggestions for hose material,i think its 6mm or 1/4,pushed on a barb with a clamp.Will try to fiddle with it the next few days but then im of for work for a while.