I would like to run my murex mig on gasless wire, could anyone tell me if I can get a knurled wire feed roller for a murex mig or would it be possible to use 0.9 wire in a 0.8 roller to grip the wire any ideas welcome.
Which model of Murex? And are you talking gas-less or flux-cored?
A lot of the larger Murex machines will run flux-cored wire (together with a shielding gas) but gas-less is a different story & the machine must have reverse polarity settings to correctly run it.
weldequip
I've found that 0.9mm gasless wire runs very well through a 0.8mm drive roller. Better than it did going through a 0.8mm drive roller. In fact, since accidentally buying 0.9mm wire, I haven't had a single problem with wire feed. This is on an el cheapo chinese made machine though, so YMMV.
I don't understand why gasless wire is commonly run through a knurled roller and plain mild steel wire through a smooth roller.
Gasless is "flux cored", which presumably means the extra stuff is in the middle of the wire. So it ought to be much the same stuff on the outside? Why the difference in the rollers?