Gasless Mig wire amount?

[Donnie]

Hi all, right other than the gas / cylinder I have everything I need to use my MIG, I was thinking that I might get a small roll of gasless wire from ebay for some small jobs, ie 0.45kg of 0.8mm wire while I save up for gas.

I was wondering though how long this is likely to be maybe to give me an idea of how long it may last if you see what i mean?

Also, is it a straight swap for the gassed wire, I seem to remember seeing a post somewhere about reversing polarity or something???

 

[shenion]

You should reverse the polarity for gasless.

Ebay may have cheap Chinese wire that is near useless. Go for a name brand. Weldequip's shop has rolls of SIF gasless.

Hard to say how long it will last. I have done some significant projects using small rolls. I did 20 feet of seam welds on a trailer using a small roll of wire. Still have about 1/4 left.

 

[TechnicAl]

As a norm gasless wire will lose about 40% to gas / slag. So for every Kg you buy you will be 600 grams of weld. So your 450 gram roll will give you 300 grams of weld.

Gas shielded you get 100% (very nearly)

 

[Donnie]

Interesting. Cheers for that guys, the only thing now is I have no idea how you go about changing the polarity on my mig, anyone know how this is done?

Ive checked and theres no switch on the front panel of my machine to do it

 

[wyn]

If it's a sealey supermig 235 it looks like it's a gas only machine and there won't be any easy way of changing polarity for gasless.

 

[Donnie]

ah, bu**er