newb needs Welding advice

I bought a Miller 140 auto-set mig welder. I have been using stick for years and decided to start using a mig welder. I thought I was getting the hang of it but something has changed and gone wrong. I was doing fine tacking sheetmetal and then I tried doing square tubing. For a couple days it seemed like I was getting good penetration and the welds looked good. Everthing was going great. I started weldng today and the wire and machine are doing different things (bad things).
When I am welding the wire doesnt penetrate know and the wire seems to meld back up itself. I tried different settings on the wire speed, tried different amperage and it seems to do the same thing.
I am using gas 75/25 blend, 030 wire, and following the dummy chart for settings in the machine. I am trying to weld 1 1/2" square tube carbon steel with 1/8" wall. The machine has a 20% duty cycle.
Any help will be appreciated.
Brian

One of my buddies just told me to clean the tip or replace it. It doesnt seem to be binding up though. Could that be the problem????

Wire speed?

Bogger,
That sounds like a wire speed issue. What heat setting & wire speed r u using? Is the metal clean & do u have a good ground? Are u usin' anti-spatter? I'm sure the Bonehead can help ya here!

BoB

metal is clean. not using anti spatter, wire speed is on 80 and voltage is on 10. I need to look at the book to see what 10 translates into for volts. It has a dummy cheat setting list next to the volts dial and it says 1/8". Ground seems to be good.

Yep, first check your ground, the wire will just lay on top of the weld if the ground is bad. Second, check not only the wire speed, but check to see if the drive wheel inside the welder is too tight on the wire. It should be light enougn to drive the wire, but that is all. If it flattens out the wire, it won't feed right. And as the guys have said check inside your nozzle and make sure some slag has not gotten between the tip and the nozzle, ( bad ground again). Let us know how it turns out.

Thanks Bonehead and Tripper, I am going to get back to it after work today. It is funny all I herd from people was "mig welding is so easy". I apparently need to understand the machine better.
Brian

39fordbooger said:

Thanks Bonehead and Tripper, I am going to get back to it after work today. It is funny all I herd from people was "mig welding is so easy". I apparently need to understand the machine better.
Brian

Click to expand...

39,
Mig is easy but there is a small learning curve. Also, I've found some days I am in the groove & sometimes I'm not.

BoB

Ok, I finished welding the 39 bed framework for the truck today. I took every piece of the above advice and one of them worked. Not sure which one was the actual problem but I did the following:

- The lugs for the ground inside the machine didnt seem tight enough. Tightened those.
- The wire seemed to be moving too slow and possibly binding in the gun. I loosened the spring on the spool and the drive wheel adjuster. The welder didnt seem to be "whining" when I pulled the trigger as much. It's cruz' out now.
- I bought a new tip and a new nozzle. Come to think of it I should have bought a tip cleaner. Mondays trip to the the supply house I guess.

I will be doing some welding on the sheetmetal panels for the bed sides tonight , so I will problably have more questions since I am going to the thin stuff next.


Thanks for all the help!!!!

This may sound simple but make sure there are no big twists or would be kinks in your line from the machine up to the gun. Also keep people in your shop from stepping on your line, over time it will break down the liner and cause poor performance.

cool, thanks worshiper!

drive gears

if the drive gears for the wire were a little tight you might want to pull the wire out take the tip off the gun and blow the liner out because if the drive gears were to tight they will grind on the wire leaveing wire shavings in the liner and that will effect how it feeds

I'll give it a try tonight. I didn't know that one.

Just the other night our Miller 210 started to give us a little problem too. This is very unusual for this welder because in the 4 or 5 years we have had it, the thing has been an absolute joy in all respects. We have welded miles of welds with it and have done nothing to it but put new tanks of fuel and spools of wire when empty. I wish everything we owned worked as well at that welder.

What is started to do was skip a little when welding. We figured out that the wire wasn't feeding properly, and when Dan put his finger on the wire coming out it was not a strong push. We found several problems. First of all, the wire was not going into the grooves on the feed rollers. A simple adjustment took care of that. Then we blew out the liner with compressed air and a TON of dirt came out. We also cleaned out the gas ports on the nozzle and now the flow is very strong.

It just needed some maintenance. It now welds hotter than it has in a long time, and tonight I used it a bunch to weld in some flooring on my Dodge, and it even made my welding look pretty good. Guess we need to start tuning up out equipment once in a while to keep it working tip top.

Don

Thanks Don.
I am antious to try these maintenance tips on my 140 unit but I havent touched the 39 in about two weeks. I spent the past week and a half getting that car bed into the house.