Mig welding problems

[Boony405hp]

I have a Lincoln PowerMig 180C. Using .025 guide, 0.6mm wire. All of this gear came with the welder. I don't seem to have much of a problem welding metal that I can clean up thoroughly and place on a plate of steel, then earth the plate ie. my welding working bench. But when I come to work on my car I am having a lot of trouble getting decent welds or sometimes even striking arcs/welds at all.

I clean up a bit of sheet metal on the car so it's nice and shiny both sides and place my earth clamp on it. Is it because the new part I am welding to the car need a better connection with the existing part?

If it doesn't strike an arc or a very good one as soon as the wire pushes against the metal it seems to fowl back in the machine as shown. This is really frustrating having to pull a heap of wire through and not being able to do even a simple tack weld. Please note in the pictures the gap looks bigger then it was when I first attempted it's mealy there to show you what I am trying to do. Hope someone can help. Dave

 

[cumbriasteve]

Your earth clamp area may be clean but you also need the area you are welding clean, it is also possible you are attempting to strike on the part of the metal that is not yet welded to the section that is earthed.

Just because the 2 sections are in contact does not mean there is a good earth transfer across them, especially if there is any dirt or corrosion on the surfaces.

It's also worth backing off the tensioner on your wire feed enough to allow the rollers to slip rather than continue to push the wire through, looking at the thread you have it screwed well down if not right down.

 

[normspanners]

By the look of you pictures you do not have the brass capilary tube that fits in the lance/torch flexible pipe, after the liner is slid in, therefore as the wire is being pushed by the rollers there is nothing to keep the wire straight and true this will be fine on the bench because the torch will be straight as soon as you bend it when working on the car it puts added resistance to the wire and BEND you have your snag, the brass tube needs to be as close to the rollers as poss, I try to make mine virtually 'rub' the rollers and even put an angle to match the contour of the rollers .

 

[normspanners]

like this, wire direction from left to right

 

[cumbriasteve]

like this, wire direction from left to right

I wondered about that and you are probably correct, I was distracted by what appears to be the 'stud mount' coming across from the unit at the wire entry point.. appears as if it would obstruct things...maybe just the way the photo is.

 

[normspanners]

'Roger on that one good buddy'

 

[GrahamGKD]

Is there a part missing from the wire feeder - or maybe the OP has removed it so the picture shows what has happened to the wire?

See this picture of a similar wire feeder.

 

[normspanners]

I dont think he has removed anything because the wire is bent directlly from the brass ferule. IMHO

 

[cumbriasteve]

Is there a part missing from the wire feeder - or maybe the OP has removed it so the picture shows what has happened to the wire?

I think it's just a cover plate thats been removed for the photo, screws into the 2 circular mounts that are showing in his photo...perhaps designed to keep the working clear of dust and debris etc.

 

[GrahamGKD]

...well, whatever, I think there must be something missing, surely it would be a leap of faith to expect the wire to feed across such a wide gap unsupported without buckling (as it has done in the OP’s picture)??

 

[Boony405hp]

Hi guys, thanks for the replies. Usually I push that brass feeder tube right up against the rollers, I may have pulled it out after it jammed. I will back the knob for the roller pressure but I think the main problem is a striking through the non earthed part. I cleaned off an area on the inside where I wanted to strike the tack, but perhaps the other areas it is touching need to be cleaned up a bit. I'll do these things and let you know how it goes.

 

[normspanners]

surely it would be a leap of faith

good analergy
or
A LEAP INTO THE UNKNOWN !! HA
or
wire walkin the Grand Canyon

 

[normspanners]

How does the feeder tube stay there? it should be clamped or poss held by the end of the liner. By the look of it in photo the wire has bent and then pushed the tube down towards the torch, you will never get it to feed properlly if it is loose!. I would say that is the cause of your probs because if you have the slightest bad earth the wire will immediatlly kink as it 'stubs' the work in a milli sec. and then take the tube with it. Then at the same instant the wire stops in the tip it then arcs there and compounds the problem, I have had this problem countless times, untill I set the tube to 'rub'.

 

[GrahamGKD]

.... this is distracting me from what I'm supposed to be doing now (because it's more interesting, I guess)

The spec for the wirefeed unit talks about a patented split wireguide. Pictures on the the Rapidwelding site show a groove in the open space of the wirefeed unit - (also just visible in the OP's picture behind the wire) probably complete rubbish but I'd put my money on that cover plate is supposed to trap the wire into the groove and keep it restrained there while the wire is feeding.

 

[GrahamGKD]

good analergy
or
A LEAP INTO THE UNKNOWN !! HA
or
wire walkin the Grand Canyon

....or 'wire like a d*ck in a dustbin' - we could go on....

 

[normspanners]

The spec for the wirefeed unit talks about a patented split wireguide. Pictures on the the Rapidwelding site show a groove in the open space of the wirefeed unit - (also just visible in the OP's picture behind the wire) probably complete rubbish but I'd put my money on that cover plate is supposed to trap the wire into the groove and keep it restrained there while the wire is feeding.

Well found that man!

this is distracting me from what I'm supposed to be doing now (because it's more interesting, I guess)

HA HA !!Thats exactly what the wife says to me about the mig welding forum, but she doesnt say it quite so eliqaintly

 

[GrahamGKD]

HA HA !!Thats exactly what the wife says to me about the mig welding forum, but she doesnt say it quite so eliqaintly

...my Mrs is the same - I tell her I wouldn’t be able to do half the stuff I do without this forum (which is true, of course).

 

[normspanners]

Well mr Boony 405hp whats happening ? we are in suspenders here!
is itor what!!!

 

[Ed.]

I would also agree that there appears to be some "bits" missing. It needs a tube and the spiral wire sticking out closer to the roller or at least another tube.

 

[armalites]

Why not get a jump lead and link the 2 pieces of metal together?