Another stupid welding question.

The welder is a Miller 211 MVP on 220 volts. Strong wire with dedicated wiring for the 220 Volt garage. Wire Lincoln S-6 MIG
Gaz Argoshiel Light from Lindle / Air Liquide.
The metal on this picture is about 0.75 mm. Size does not matter, same behavior for other ones.
No wind, welder in the garage.
I keep the wire about 1/4 from the gun.
Metal cleaned as perfect with a wire brush.

All is dark, like a carbon deposit.
This gives me contamination .

I just make shit.
Sometimes I see the weld growing as a mushroom.
What am I doing wrong ?
Thanks.



Philippe.

 

are you sure youre getting gas out of the nozzle?

Though no gas would be a worse looking weld, looks more like a heat/feed setting issue

 

Looks like you need to turn up the heat and slow down a bit.

 

I have gas. I tried using more or less. Didn t been enough. When I give more heat, I just make holes ...
I do really slow.

I m aware it s not a Tig . So can t expect a perfect result. But it s a correct MIG. I can t have it good and it s far from my job. Learning ..
I really thing the faulty is me, not the tool . But can t get it having a nice result

 

It looks like a polarity issue to me. Is your welder set up for mig or flux core wire?

 

looks like your not keeping your tip steady and moving in a constant direction...

 

if you are growing little mushrooms your weld is dirty. everything has to be clean. even the wire.

 

What size wire ? .75MM is thin like 22 gage ,you need .023 -.025 wire thats like .55-.6 MM

 

.75mm is .030", VERY thin material. You'd definitely need the .023 wire for that.

You say it does the same thing on thicker metal? Is the welder popping, like it's having trouble maintaining a constant bead? You may have a bad ground path, OR a wire feed problem.

Try welding on a small piece of CLEAN metal with the ground clamped directly to it. Make sure the gun cable is not wrapped in a loop or pinched at the gun handle. Let us know if it does the same thing.

 

Guys, look at the spatter and discoloration around the HAZ. I am no weldor but that looks like shielded wire spatter, discoloration. No gas? Wrong wire? Wrong polarity?

 

Dirty/contaminated/rusty base metal.

 

How good's the earth connector, at the welder end too

 

The back side of the weld seam has to be as clean as the front,or it is alot more difficult to weld.

 

Reverse the polarity, like a few have already mentioned.

 

He verified that it DOES have gas flow, and the welds look a little "too" clean for no gas. They are fugly, but don't have that lava rock look to them.

 

Yea, when I forget to turn on the bottle, I get a real funny porus weld, its easy to spot.

 

Thanks for the suggestions.
My metal IS clean, cleaned with a clean wire brush. In fact it was painted before, so there s no rust at all.
I ll try cleaning the gun liner, maybe this should help ..
Of course, I didn t mention it but the wire is 0.023 of course. Metal is 0.035
I don t expect to weld it as easily that 1/8 or 1/4, but i would like to get rid of this black stuff. It looks like smoke deposit ..

 

After all the equipment checks have been done it comes down to fine adjustments on heat and wire speed and technique. ie: how long you holding the trigger, where you overlap welds on the bead, how big the material gap is, adjusting for thin spots, where you aim your wire, etc...

 

I would also recommend (if just for testing anyway) to clean the metal with a scotch-brite pad soaked in some sort of organic (citrus, etc) cleanser. We weld day in and day out on new 18ga (.048) cold rolled samples with NO blackening whatsoever.

 

Almost all MIG welders have a chart under the lid where the wire is stored that tells you how to set up wire speed and heat according to your wire size and material thickness. That is always a good start then you can fine tune it from there.

 

Where's Fitzee when you need him?

 

Add one more.

Bob

 

Ot... I love Felixspeedshop's avatar pic. Lot of that in nebraska!

The wealth of knowledge here will help you. Their the best! Good luck and keep welding!

 

first off there are no stupid questions only the ones you dont ask theres more knowledge on this board than you could ever pay for so ask away my 2 cents polarity and no gas or low setting

 

I'd check polarity and turn my wire speed down a little.

 

Polarity is correct . I ve checked at least 3 times.
It s a new gas bottle. Now I wonder if there may be something wrong with it ...
It tried on other pieces of metal, I still get this dark deposit ...
I ve been problems with my gas supplier twice. One bottle half or less filled. I took me one week to have it empty . Usually they last 3 months, I don t weld a lot. And yes, I did shut it off .
Another one with the valve impossible to open.
I returned it to the shop, they also could not open it using grips. Like welded ....
I ve checked many websites about mig defects, no one mentions what I have .

So maybe this could be the cause .
For now, I have better results with my cheap 250 $ Mastercraft and flux core 0.030 than the 1500 $ Miller, 0.023 Lincoln and Argoshield
Something must be wrong ..
Maybe me. But I still can t find what .

Look at this. I know it s rusty. I cleaned the edges before welding. It was just a quick test.
I ve been working in a machine shop, welding steel or stainless, but never had this kind of deposit .. I m not a great welder. But this is ugly .
I usually make better welds.

 

I have a millermatic 180 at work that does the mushroom growing thing sometimes. Im no ace welder and I dont always clean my metal perfectly but I dont seem to have the same problem at home with my migmaster 250 or millermatic 130 or little blue point 120v. How do you check the polarity?

 

Also my bud John Walker (also a H.A.M.B.er) has a millermatic180 that gives him hell and he is way better than I.

 

The polarity is easy to check. There s a drawing inside.
I ve been switching to flux core vs solid wire several times, you can t miss it.
I just checked now again before answering. It s ok.
But I thing it would give bad penetration, craters, but not the dark deposit I have to face .
Tomorrow I ll use the gaz and solid wire on my cheap chinese welder .
Just a try.

 

I know you checked 3 times and I'm just trying to help,,,,

It's hard to say exactly, but it does look like a polarity issue.
You do know flux core and mig need opposite polarity ?
Have you tried switching it just for fun and run a test ?
It should be labeled inside the machine too.

As far as gas goes, the mix could be bad, wrong gas that doesnt match the lable, or contaminated. sort of looks like straight argon weld but not exactly.

Try a different supplier or borrow a bottle or take your bottle to another welding machine and try your gas on their machine. That will confirm the gas issue.

I see you typed at the same time.