Hi Guys,
After stuffing around with my MIG welder for some time now I've finally got it working well on Aluminium!! I'm happy as a Pig in poop since aluminium welding has been something I've been wanting to do for ages.
The welds aren't as nice as what you can do with a TIG but they are acceptable for what I want to do.
machine set up is a realy important factor in welding aluminium and it's a lot more sensitive to wire speed and voltage settings than steel. The other issue is getting the wire to feed properly and I think I've sorted this out as well as I haven't had a jam for ages.
One of the traps is that the teflon gun liner that most shops sell you for a Binzel gun isn't the whole kit. And if you install it just like a steel liner you're in for a bunch of trouble. What most of them sell is just the refill kit. You need a the wire sleeve that goes inside the gun and a brass tube for the wire guide back at the rollers.
The sleeve in the gun screws onto the end of the liner and feeds the wire up to the tip. If you install the liner without this on the last 8" or so of the liner the teflon liner melts on the back of the tip. The brass tube for the wire guide is important to keep the liner straight and butted up close to the feed rollers. The tip is also important in that you have to go one size larger than the wire you are using or buy tips sized for aluminium. Since the expansion rat of aluminium is greater than steel the wire can expand inside the tip and jam inside the close fitting hole. I'm using 0.9mm wire but running it through a 1.2mm tip.
To celibrate I knocked up my Quick Jacks. Chris Lidgerwood had some blanks water cut for me from 6mm aluminium plate. I linished them up and welded them together. I've just got to linish down the weld on the back and polish them and they are ready to bolt on.
Cheers