mig problem

[norlander]

it looks like you are still trying to weld on crap. Cleaning crap up can contaminate the abrasive you clean crap up with.
Get a new clean disc on new clean steel and try again.
Get the steel from a proper supplier, I had similar results when I tried to weld some crap metal from a place far away.

 

[mike 109444]

I wounder if you are trying to weld something beyond the limit of your welder. "I own since a few weeks a LITTLE telwin welder" As the plate you are trying to weld does look quite thick and the nut certainly would be 5 to 6 mm thick on the side walls ?
Can you post a pic of the data plate on your welder like the pic attached. The figures circled are the key ones that indicate the power of a mig.

 

[mike 109444]

Also post a pic of the front controls as they are set when you have been trying to weld your test pieces.

 

[azazello]

Tried in all configurations... in the afternoon I switched back to flux and welded 2 mm steel setting the voltage to max-1. (If I am riht the amp are given by wire speed, aren't they?)

 

[norlander]

I am not sure if the wire speed control fine tunes the power , I don't know the answer to that,sorry, the welder does not look new?
It seems like its a problem with the gas if it welds ok with flux wire?
Maybe there is a leak? I do not if that would cause the problem but it could be worth checking, maybe if you can strip the torch down to check connections,and check the hose to the torch you might find something, I am only guessing though.
Good luck, it must be very frustrating, but the answer is there somewhere.

 

[azazello]

Had a try in aNother workshop both with a new gas tank and with mine: it works... but at home I do not have the same result...
Asked an electrician friend of mine and turned out it could be a problem of wire section in my home workshop electric system.
Will try to sort out, but it does not seem a simple affair...