mig problem

[azazello]

I own since a few weeks a little telwin welder; it came with flux equipment and I learned to weld sheets of metal without gas, with the proper animated wire.
Last week I bought a tank of ar/co2 mix and the kit for linking to the welder.
Unexplicably it seems unable to solder well enough with this new equipment.
An expert friend of mine came to try and help regulating the gas flow but with no result.
The welder works very well in the flux configuration, melting the metal and making good joints, while in the mig configuration it just builds up balls of metal without melting the metal I would like to joint, and the two pieces usually come apart too easily.


In the photo you can see the long and regular weldings made in flux configuration and the metal blobs made in the mig configuration. ..
I always thought that with the gas the welDing quality could just be improved...

Thank you all guys!

 

[mike 109444]

Are yo swapping the polarity around when you switch from fluxed to gas ?

 

[skotl]

I am guessing that you were using "flux core wire" before. Are you now using pure steel wire?

 

[norlander]

Hi azazello,
make sure that the gas is getting through.
And, are you using copper coulored wire with the gas?-If the wire is silver, it's for no gas.

 

[azazello]

I swapped polarity as per instruction an tried both combinatikn (all the people I asked for this problem didn't know there was a difference of polarity) and yes, the wire is copper plated and named "for steel" (not inox). I even bought 2 different brand of wire to see if the problem was in a wrong wire...
The gas is coming, with the wire speed set to zero if I put the "gun" near my ears I ear the pfffft of the gas... I do not have a flowmeter, but tried with different amounts with no differences...

 

[norlander]

did you get a big tank of gas or small one? I have read on here that it is possible to get a bad tank of gas.
This would be difficult to check unless you can change the tank or use your tank on another welder.

 

[cumbriasteve]

I agree with all the above ..it certainly looks like a gas problem to me, either the wrong gas or lack of gas.

Are you welding outside in a windy area by any chance?

 

[azazello]

It is a big tank (14 litres) and not a disposable one. Bought full of mix argon/co2 a couple of days ago from a well known local provider...
I am welding in my garage with no wind.

Thank you all guys, I will try bringing my welder to someone with a tank of gas and look wether the problem remains or not...

 

[mike 109444]

As you have been using flux core, worth checking the shroud to see if there is to much splatter blocking the gas flow. Did you change the tip for a 0.6 or 0.8 from the one for the flux core (0.9 ?)

 

[T0rnado69]

just a thought as you was using fluxcore wire.

have you changed the feed roller, as fluxcore is 0.9mm ?
or maybe 0.8mm over there.

and gas wire is 0.6mm and 0.8mm

unless your fluxcore wire is 0.8mm and your now using 0.8mm gas wire.

 

[azazello]

I changed the roller side, from 0.8/0.9 of the flux wire to the 0.6 side of the steel wire...
The gas is flowing, I can ear it from the gun, but I am using a 0.8 tip with a 0.6 wire... is it a problem?

 

[mike 109444]

I changed the roller side, from 0.8/0.9 of the flux wire to the 0.6 side of the steel wire...
The gas is flowing, I can ear it from the gun, but I am using a 0.8 tip with a 0.6 wire... is it a problem?

Yes the contact tip is the means by which the welding voltage connects to the wire. So with a tip of the wrong size (OR worn) you will get a poor transfer of power. This may go someway to causing your problem.

 

[azazello]

Yes the contact tip is the means by which the welding voltage connects to the wire. So with a tip of the wrong size (OR worn) you will get a poor transfer of power. This may go someway to causing your problem.

I will definitely give a try!
Thank you!

 

[azazello]

Tried with 0,6 tip, goes better but still not enough penetration...

 

[dan.taylor.1]

You'll never burn through that much rust and the pipe looks coated, you NEED to clean the weld area before welding to minimize any issues.

 

[norlander]

can you try some welds on bright new steel? that steel in your images looks rough? the bolt -and guess the nut appear to be galvanised, which probably will not help.
edit: dan beat me to it, what he says.

 

[azazello]

Ok!
In the afternoon I will try again cleaning the surfaces...
But with the flux welding never had this issues!

 

[norlander]

But with the flux welding never had this issues!

I think fluxcore runs hotter than the equivalent diameter wire for gas, so it might burn through less than perfect steel.
Hope it goes better when the steel is cleaned up.

 

[PTvor]

Fluxcore is more like arc. Arc will cope with an incredible amount of rust, however, to do a proper job, even with arc, and certainly if you are having problems, you need to clean the steel back to bright.

 

[azazello]

Then. Cleaned the plate from rust and the tube from zinc with a grinding disc. The nut was not zinc coated.

(The 2 on the right, much cleaner but still not penetrating)



I think next step should be trying with another tank of gas....