Newbie has odd welds

[FJ12jagman]

I am using a second hand Migatronic Rally 166 with CO2 and am getting inconsistent welds.
I have acquired lots of off cuts of new mild steel sheet (1mm) to practice before I weld my Mini back together. I have spent a lot of time adjusting the speed with one hand whilst welding with the other. Once I hear the sizzling bacon noise I believe I am somewhere near, swap to both hands and continue the weld. All goes well for about an inch, there's a stutter, no weld produced then it comes back again (see photo) 1) is obviously rubbish 2-5) I didn't change the settings but on each line can be seen the break.

Any help appreciated.

 

[the snooper]

how old is the wire , check for rust if old and it may need a new liner check the wire feed mechanisim aswell sounds like the wire is being fed erratically

 

[FJ12jagman]

Thanks. Wire came with the machine, looks alright but I'll change it and see what happens.
The bloke before obviously had problems with the trigger and has taped a bit of cable from the trigger, along the torch and into the side of the machine where he's block connected it to the original (I presume) wires. I've checked the connections at both ends, seem alright.

 

[Daveleonard]

mig problems

Hi no expert but have a go at cleaning the liner and some new wire, seen this problem on an old clark fitted a new liner all went ok from then on.

 

[Sean]

check what the contacts in the torch are like - Cebora had little hard contacts like old points , they got oxidised with all this on off stuff, I had to keep pulling the trigger apart and polishing them.

new tip?

 

[FJ12jagman]

Thanks for replies.

Bought 5kg of new wire yesterday, seems to be on a smaller drum than the one I've got. Will try fitting in next couple of days, may need the adaptor I've seen elsewhere.

The trigger is operated by a sealed micro switch. Don't know how to check this, will try wire and cleaning/replacing liner.

 

[PaulMcElhinney]

Hello Jagman,

Enquire whether you can get a steel liner for your machine. They resemble curtain wire. They are significantly more rigid than teflon liners and aid smooth wire feed. Ask Steve at Weldequip, he'll know.

Good luck,

Paul.

 

[FJ12jagman]

Thanks Paul good idea, I've PMd steve.

 

[the snooper]

as far as i remember the 166 came with a steel liner as standard, you could also try blowing out the liner when you cahnge the wire