Smoke and spatter while MIG welding, why?

[KMinAF]

Problem solved! After checking the gas, wire, nozzle, rollers, grounds etc, etc and doing an extensive internal cleaning, I still had the same problem. In my frustration I started to wipe down the front panel and noticed the wire speed knob was loose! After securing the knob so that it actually turned the shaft I was able to increase the wire speed which resolved the problem. I hadn't noticed the obvious before because I had always adjusted the settings while wearing my gloves. The how, why and whens of the offending knob will I guess, be forever unknown. Rather embarrassing.
Thanks to all who responded, its nice to know there are people out there willing to share their expertise.

 

[AMCguy]

Great news. Weld on.

 

[R.Anderson]

You knob.

Jk

Someone had to say it

At least you did not send yours in for repair. I sent my Miller passport in on warranty repair twice for something way easier than that. After the second time they told me what was wrong, nothing. Turns out I was bumping the button in front that switches modes. Steel, stainless and aluminum are the modes. When it's on aluminum the trigger on the MIG gun will not function.

 

[BigMike782]

If you are a home shop machinist type you will understand,
clumsy *******
Glad you figured it out.

 

[Tinner]

Ok let me expand on this.

As a "general" rule of thumb and more so with thickness less than 1/4'' You can't go too far wrong with 1 amp/.001'' Having said that, The higher you get over 1/4'' the less it applies. For example, you don't need 1,000 amps to weld 1''.

Now you can weld greater thicknesses of metal with a lower amperages but that requires joint preparation and/or multiple passes.

The above rule of thumb takes into account you are trying to achieve maximum penetration with a single pass with little to no joint preparation and the joint must be no weaker than the parent metal.

Yes you can stick two pieces of 5/16'' steel together with 125 amps and the weld's surface appearance may be pleasing, but the weld will not penetrate enough for it to be as strong as the parent metal. That's fine for let's say a table frame where the metal chosen gives the frame rigidity and the weld simple holds the whole thing into the desired shape. It's another thing all together when the weld will be highly stressed or subjected to destructive testing.

In the OP's picture it's clear he's doing an inside corner weld. This will always take more heat. In this case I really don't think he's got enough machine, but I do think he'll get a better result if he tries what I first posted.

I recently took a certification test for a European manufacturer. 1/4 fillet weld on 1/4 plate, both sides. No joint prep. The parameters were 125-135 amps. 70s wire, .030. They cut 4 1" sections out of an 8" coupon. Ultrasound 1, bend 2 (1 in each direction) acid etch the last. They expect 1 to 1.5 millimeters penetration.

Run the same test at 250 amps and show me what you get.

I've been doing fab work for 40 years, lots of places making lots of things. Never ran as hot as 250 amps on 1/4 plate, for a test or otherwise.

I'm not saying it couldn't be done, but 250 amps on 1/4" plate would leave you with a distorted mess, with considerable porosity.

Fillet welds generally don't require 100% penetration and when they do joint preparation is how you achieve it.

I don't know where your "rule of thumb" comes from, but it sounds to me like a silly theory that is never used in practical application.

 

[tonyciambrone]

That looks to me like you're not getting a proper gas flow. I had a weld look the same when I forgot to open the valve. Can you hear gas hissing out the end of the gun when you pull the trigger?

Hehe...I was just going to comment. I did this once, and I was thinking "Man this weld looks terrible, it almost looks like I'm not using gas!"

Then I looked at my regulator. Low and behold, no gassy gassy, welds look crappy crappy

 

[bdbecker]

...In my frustration I started to wipe down the front panel and noticed the wire speed knob was loose!...

View media item 67851
Glad to hear you figured it out!

 

[Streetbu]

I'm gonna need a bigger extension cord!

There's your problem, Get rid of the extension cord, I don't care what size or length it is. You're not getting enough voltage to the welder.

Posted this before I finished reading the thread. Thought I had it for sure! LOL

 

[Superbec]

There's your problem, Get rid of the extension cord, I don't care what size or length it is. You're not getting enough voltage to the welder.

Posted this before I finished reading the thread. Thought I had it for sure! LOL

nailed it, just like the rest of us ....

not enough wire speed.... one would think any trigger monkey will notice that in the first 2 seconds of arc ...


take that internet counseling.

 

[chaosracing]

Just wondering why the negativity towards extension cords? All the welders I ran (120v and 240v) for the most part have been run off extension cords. I used to run demolition derby cars and tough trucks, and when we welded the cars up or welded cages in the trucks, there is no way we could have done it without extension cords. We properly sized the cords we were using and never had any problems.
I know someone else that had his own shop for trailer repair and fab and his welders ran off 50' extension cords. Never had an issue.

Now I have had problems when using my 120V welder if the outlet I was off of was 15 amp and not 20 amp. And then it gave problems when directly plugged into the outlet.

 

[Superbec]

Just wondering why the negativity towards extension cords? All the welders I ran (120v and 240v) for the most part have been run off extension cords. I used to run demolition derby cars and tough trucks, and when we welded the cars up or welded cages in the trucks, there is no way we could have done it without extension cords. We properly sized the cords we were using and never had any problems.
I know someone else that had his own shop for trailer repair and fab and his welders ran off 50' extension cords. Never had an issue.

Now I have had problems when using my 120V welder if the outlet I was off of was 15 amp and not 20 amp. And then it gave problems when directly plugged into the outlet.

because physics ... voltage drop= more amp draw ... you could observe this much easier with a large electric motor like one from a compressor .. it will sputter or just not start at all.

 

[chaosracing]

I understand the voltage drop due to the physics of wire size and type. I learned that at a very early age since dad worked for local electric company. However, like I said in my post, if the cord is properly sized, there should be no concern. Its the same as a circuit run. Wire and breaker must be properly sized to handle what will be used on the outlet(s) on the circuit.

Again, if I did not use an extension cord, my welder would be pretty much usless. It has a 6 foot cord from Miller and then the gun length (5 or 6 foot) so if I stretch it, I can go say 11 feet away from my outlet. No way I can weld around a vehicle, on a trailer or other stuff. I use a heavy duty 25 foot 12 g extension cord (I have a Miller 135 110v welder currently) and have never had an issue, except when after first moving into my house. The outlet right below the panel was made for 15 amp. Once I changed it over to 20 amp, I have never had an issue at all.

Properly size your equipment and cords and circuits and you will never have any problems.

 

[Superbec]

Properly size your equipment and cords and circuits and you will never have any problems.

well you do , but most people don't

 

[Alcohol]

I have burned up MANY bottles of argon. If you look around the slug area where your shut off valve is there may be initials DT ingraved in the bottle. This means dip tube,,which means there is a tube screwed into the bottom of the shut off valve that extends down to near the bottom of the bottle. This tube is essential for a mixed gas flow,,75/25,, I have had bottles without the tube and when they get low on gas,your welds will be affected by smoke and spatter as well. The welding supply store alerted me on this issue.