Bear in mind that i am still learning and I am not doing this for work, but simply for hobby So I took a welding course ages ago, and started mig welding again off and on about a year ago, my welds are not pretty or even close to weldporn status, however they seem pretty strong, have good penetration and dont look awful. But every now and then when my settings are correct, ill get more of a whoosh sound when i pull the trigger, i assume its the gas coming out, and then with the exact same settings it welds a really nice weld like this. It also sounds a lot less crackly and pools the weld really nice My question is, is it possible that my welder is not always feeding gas properly and thus im technically welding with just the flux in the wire? The welder is a Matco shop mig welder (mwld140) 180amp, i have not been able to find any information online about it. Any help is greatly appreciated
Get someone to watch the flowmeter on your shielding gas bottle. It should flow every time you pull the trigger. If not, maybe a bad gas solenoid.
so you're running gas and flux core wire? what gas are you using? what wire? do you have pre flow control on the mig?
Not using flux core wire, i thought all wire had a little flux in it, but I only thought that because I was told that, I am welding with Co2
You can use shielding gas but it is not imperative to use gas with fluxcore welding wire. In other words, the out come of the weld shouldn't be dependent on gas flow with fluxcore, unlike using solid wire that requires shielding gas. Neither one of those pics look like fluxcore weld to me, especially the nicer one, and your explanation doesn't fit fluxcore wire either. Turn on your welder, turn down the wire feed to the lowest setting, stand by the bottle and watch the flow gauges as you toggle the trigger. Observe the sound and flow from the gun as you change the flow settings, what you hear should reflect what you dial. If there's a problem start checking for problems. Use a methodic Process of elimination and see where the gas flow stops.
aside from the possible gas flow problem, stick-out length of the wire from the tip needs to be consistent (and short) to make uniform welds, sometimes if you're not watching that closely, you can get the gas cup further away from the material and it sounds different, and the resultant weld is very different.
I figured it out, i took the gun apart and the trigger had been installed backwords and was not contacted the gas switch everytime, i turned it around and now it works great
Surprised you got as good a weld as you did with the gas malfunction..Good you dug into it and found the problem.
I'm not aware of a trigger with more than 1 contact. That single contact starts everything, power, wire feed and gas solenoid.
. Yes a much cleaner weld with the mixed gas! I have a next door shop that uses co2 straight and I can not weld with there welder for shit! I always wheel mine down there when I need to weld something on one of ther lifts. Gary
Thanks for the info on the gas, Before work tomorrow Ill trade it in for that mixture at the local supply shop.
Solid wire has no flux, it does contain some silicon and aluminum in small quantities that act as deoxidizers. The 75 % argon and 25 % CO2 will be a much better gas mixture. I also can't see a switch being backwards and not contacting a "gas switch". I would have to see pictures of that. Most machines use an electric solenoid and it and the wire feed are triggered by one switch in the handle of the gun.
You shouldn't or don't need to use core wire and gas at the same time use one or the other. The whoosh could be the line purging as the initial gas comes out or if it is whooshing while it is welding instead of crackling then you have the wire feed and temp/map setting so that it is welding like that, I like the whooshing noise as opposed to the crackling sound, but you have to really move along or your burn the hell out of stuff. Oh the look on your second weld is good for a wire feed.
Had a similar issue with my Miller once, new bottle, looked like flow but no gas at the nozzle. Started back tracking and found out the cord was pulled out of the machine just enough to block the gas passageway. Its often something simple (like your switch) Just keep backtracking till ya spot it. Good luck with the future
My small 110 welder would go from frying bacon sound to just a rush of air sound and welded funny when it did this. The wire stick out also would burn way back up towards the tip at the same time. I found out that I had bad connections in my gun and ground clamp. Once I took both apart and cleaned all connection, it welded perfect again. I can't say for sure if it was actually in the gun or the ground clamp. Sounds like you may have found a bad connection in your gun.
For short arc welding at below 175 amps 75/25 is the most used gas. You can also use a 85/15 if you also use short arc, pulse and spray modes thought this usually is a compromise. You will need usually 180 plus amps to spray. If you don't have enough gas coverage your welds will pin hole and if you forget to turn on the gas, you will a a lot of black soot on your weld, you will know immediately something is wrong. Not having a good ground and welding on metal that's not properly cleaned will usually cause most of your problems. Having a top quality welding machine and proper wiring to the machine will also effect your weld. I've been in the shop for weld testing and there could be three welders testing one after another. All three will use a slightly different setting and the result is the same. Stick out, gun angle, speed, wire size all can play a part.
Just throwing this in as a possibility - it's difficult to tell from the pics but do give yourself a fighting chance by having the metal to be welded as clean as possible - ground or blasted. Admittedly not as much of an issue with mig as it certainly is for tig, but if you're chasing down a problem remove as many variables as possible. There looks to be a brownish soot deposit which is kinda normal. But those horrible snots were there beforehand so was the metal contaminated with soot or other contamination when the snots were applied. Agrees on the argon mix gas. The weld will be smoother in appearance and the sizzle sound will be different. Been a while since i mig'd but i think you'll increase the amps over CO2 so will be hotter, more penertation etc. Chris
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