Frustrated with mig welder-round 2, no gas.

a new thread will get attention...i now have the wire feed working on my Lincoln Electric mig welder...hey! i can weld! some anyway, but (most jokes aside) i don't have gas. I'm told:

If you have no gas, the weld will be 'orrible.

No penetration , little heat, very sparky and end up porous and sitting on top of metal, like a globule of lava.

To check for gas, release wire feed roller from wire and put nozzle to ear and listen for gas.

...and that describes it. i tested the regulator (new) and i know that the tank (new/exchange) has contents. how do i trouble shoot the welder? (as usual, the manual isn't much help.) i know 'yall can do it...you did it on the wire feed issue.

What was wrong with the wire feed? That may relate back to the gas problem. Its likely the small feed tube is punctured or pinched.

Why not add a gas flow meter on the top of the tank? This also acts as the regulator. They aren't that much and you can then fine tune the gas flow for your particular welder. There is a little ball in a tube and it will give you an obvious visual indication of the flow. You do already have a pressure guage on the tank right?

the wire feed problem ended up to be a combination of slightly rusty wire (peel off a couple of feet and trim it) and a VERY dirty sleeve in the hose. the situation was probably not helped by the fact that someone has been generating a LOT of sawdust building bookcases for the missus. disassembly of the feed mechanism, trimming the wire, and a liberal use of compressed air EVERYWHERE seems to have fixed the feed problem. i am going to use the bit of cloth, clothes peg, and mig oil trick when i get some mig oil.

i have a new dual guage regulator. tank contents one guage and flow at cubic feet per hour on the other guage. the regulator/guages function just fine with the (new) hose to the welder detached, thus i'm not suspecting that part of the system.

hmm. feed tube? i'll have to look for a flow meter like that.

You've got the tank valve open, right?

yep. tank valve is open.

There should be 4 little holes in the tip, I use a piece of the wire to clean them out, or try a new head, they are only a couple of bucks.

If the welder was never used with gas before then the solenoid valve the operates the gas may not be hooked up. Locate the valve and listen to hear if it clicks when the trigger is pulled. also make sure you have the polarity right.

When you pull the gun trigger you should hear gas at the gun tip. If you don't have a flow meter then make sure that your second gauge (flow per cubic feet/hour) shows a flow. If not then pull off gun assemble from main welder and plug in the power from the gun while the liner is out and see if you get flow (at the main welder) when you pull the trigger. If so then the problem is in the hose some where. The gas does not go thru the removable liner. (I would break down and get a new liner and tips and install them at the same time. They are relatively cheap and should be clean and free of any kinks. Attempting to clean a liner that has been clogged is not worth it. You need to have the wire and liner clean and in good shape to put in a good weld.) If you still get no gas then it is probably the solinoid (sp) that controls the gas or the hose from the solinoid to the wire feed.

On another note. Just because you have a weld with porousity does not mean that there is no gas. Dirty wire, oil or paint or crap on the base metal, a dirty liner, not enough gas flow, wind can all make a bad weld. The best way to "set" the welder is to get some scrap. Set the amperage range (if you have a setting), turn up the wire speed and begin to weld. As the wire is coming out (welding) then turn down the wire speed until you get a smooth flow (no jumping of the wire - too fast wire speed- and no burn back to the tip - to slow wire feed). You can almost do this by hearing the weld. It will be a smooth continous sound.

Would help if we kno what model welder you had. I had your problem when I had to pull the whip of the box to fix a wire feed issue. Turns out I had not pushed the whip backinto the box far enough to engage the O ring that sealed the whip to the gas orifice on the box.

I could hear the gas solenoid clic and there was gas flow, it just did not make it into the whip. ("Whip" is the term I use for the long flexible lead between the gun and the box)

Pete

Did you leave the regulator open over night? If I accidentally forget to shut off my regulator the bottle will leak to empty in a day. Expensive mistake, only did that once.

i know i've got gas in the cylinder and i know that the regulator is good...the other suggestions i'll have to check out tonight after everyone else is in bed....since thats when "dad garage time" happens.

the welder is a Lincoln Electric. a 125, maybe? couple years old.

Then the feed mechanism should be close to this picture. (If it can be seen in the image I found)The whip plugs into the front and has an O ring seal. Make sure it is fully engaged.

What wire are you using, solid or flux core and what size wire? what size metal are you welding? Are you doing this in and open area thats breezy or no air flow? IS the polarity correct? IS this a 120v or 220v unit?

If its a 120v unit and was used quite a bit, it might be burnt up on the inside. Does it seem to work fine and then after some use it starts welding crappy? Reason I ask this is 120v welders ahve duty cycles, and if you over use them you will burn up the internal components and they will soemtimes start welding fine, but after continued use they start acting like crap.

If I remeber corrcectly, my little 135amp 120v unit hada 10 percent duty cycle, which really limits the use. A welder with a 10 percent duty cycle can weld for 1 minute out of 10 minutes at full amperage, then must cool for the remaining 9 minutes. So say your 125amp welder has a 20 percent duty cycle and your welding at 40 amps, you can weld for about 6 minutes and must allow it to cool for 4 minutes, and it gets worse for an older unit, especially if previous owner was burnign crap continuously.

OK, you say that with gas line off gauges the flow meter is showing flow and there is gas hissing direct out of the gauge?

From there the tube usually goes down in to back of the welder and diasppears inside to the solenoid, then re emerges in the wire spool cavity and joins onto a fitting that plugs into where the feed/ liner assembly clips into.

You should be able to pull this gas tube off and hear if gas is hissing when you pull trigger.

If no gas there, it is a bad solenoid, if gas there and none at nozzle, it is probably blocked crap at the base of the tip.

Second hand welders tend to get bashed on job to clear slag by welders in a hurry and this bashes the nozzle and guts inside and can cover the gas holes.

Also the nozzle does wear away .

The tip should be about 1/4 inch inside the nozzle and central.

If the nozzle is worn and the tip level or protruding, it will have a lousy gas shield.

When you open gas bottle, with gas line reconnected to welder I presume the contents shows, and the flow gauge rises a bit ( maybe 6 CFM, not sure on this as I have never read it, I just go on sound and weld,)

If it does, then turn off bottle and pull trigger, does flow meter drop to zero?

Another way to check gas flow, is to dunk the nozzle shroud just under in some water and pull trigger.

Where did you get this welder from and was it used with gas before?

the problem is definatly in the welder and not in the gun, hose, or hose connection with the welder.

ok. i took the cover off the welder and identified the gas solenoid. when i pull the trigger it makes no click. when i run a test light from the case to the upper wire attachment it glows softly at rest and then clicks loudly when i pull the trigger. i assume the case is grounded. i did that a dozen times and it reacted the same every time...the first 10 times and then it wouldn't do it anymore. WTF?! do i just replace the solenoid or does this suggest a further test or diagnosis?

inside.

When you take the gas line off the solenoid (input side) and turn on your tank (quickly) do you get gas out the line? if you have gas It looks like you have a wiring diagram on the inside cover. Track circuit from gun contacts to solenoid and make sure power is going to solenoid. If so then I would say you have a bad solenoid. Go to the local welding supply and ask for a reference to someone who can supply/test the part.

James, you are the mechanical "I can fix that type" so go for cleaning the solenoid. That type can be disassembled easily and cleaned. If you remove the large nut on the top of the solenoid the coil should then slide off and expose the base of the tube that the coil fits around. At the base there are probably two indents opposite each other for a spanner wrench. I know you don't have one of those, most of us don't but usually a pair of needle nose pliers will work to loosen the housing. It should just unscrew and reveal the slug with a spring behind it. The slug will have a rubber insert in the tip to seal against a cone shapped opening in the base. Clean the tip, inspect for any damage and then clean the slug body and inside the housing then lightly coat the slug with some light oil (MIG oil would be perfect) and then reassemble and test. I clean these quite often in the equipment I maintain at work. Four of them in each machine.

ok. i'll do that tonight. nice to have a plan, thanks Bill.

ok. that didn't seem to accomplish anything. took it apart, cleaned it (didn't seem that dirty, really), oiled it, and reassembled it. does it mean something that i can't get a reaction with my test light from one wire attachment to another or from either one to the case (grounded?) with the trigger pulled or not? i did check the other end of both wires.