MIG -- what causes burnback


I played with this Dayton MIG welder today. While it seems to
function, I had a problem which was that the wire would burn back to
the tip and burn itself. It would not happen consistently, but I have
yet to find a pattern to it. I am sure that it is due to a wrong
choice of settings (and also. possibly, due to using argon instead of
25/75). The test was 0.035 wire and a big steel plate I use to test
all welders.
I would like to know how I can prevent burnback.
thanks
i
Reply to
Ignoramus18829
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The pure argon is likely the culprit. It will maintain a longer arc than the mix allowing the arc to burn back to the tip. I've run into the same problem when I didn't have enough CO2 in the mix while doing stainless.
Reply to
Wayne Cook
Wayne, I think that this is it. This welder came with an argon tank and I think that it was a bad choice on their part (it was a printing company). I do have a 75/25 tank and will try that.
the good fact about the tank is that it belongs to the welding supplier where I already have an account. As I mentioned before, I want to sell the welder, but I will not include this tank.
i
Reply to
Ignoramus18829
Burnback is a preset, and not adjustable on some welders. Stickout is a factor. Weld and stay a little farther away from the puddle. If it still burns back enough to fry the contact tip, then it is an internal adjustment, or something's fried in the machine. Look up the manual and see if burnback is adjustable or not. You can increase the stickout distance by increasing the gas pressure slightly, but you will reach a maximum distance. Burnback should not leave a BB of any considerable size on the end of the wire. Burnback is a preset so that the machine continues welding for a moment after you stop with the trigger so that the wire does not freeze in the molten puddle. When everything's working right, and the burnback is set right, it doesn't freeze in the puddle, but it doesn't continue up far enough to fry the tip.
HTH
Steve
Reply to
SteveB
No reason to use pure argon as that is most expensive, unless welding something exotic that calls for it.. Next is 75/25. Cheapest is CO2. If it's just E70 wire, you can get by with CO2, but you will have to use a different regulator, and CO2 are the cheapest.
Reply to
SteveB

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