It's a new day, I'm not a quitter...( I have to be honest it was at the top of the list of practical solutions).
I rang the service guy. He hasn't called me back since our conversation which is a definite positive as he said he would look at my old machine immediately and if it was a simple issue he'd do it without further discussion.
Sometimes explaining a problem, or indeed a whole seemingly interlinked clusterfinkelstein of them can help beyond sitting there trying to nut them out with a busy conversation in your head.
"The wire is wandering, it's impossible to lay a straight bead, like the wire is being distorted"
I went back to the shed. I reduced the roller pressure til it wouldn't drive and then inched it back up till it did...I looked at some of the pieces of wire that I'd pulled out of the wire guide after the roller had bunched it up, sure enough they were flat on one side...idiot...that solved the wandering wire issue.
Then I had a bout of lateral thinking. I reversed the torch angle. For me "hot spotting" has always worked best on light Al sheet. So I started with a "pull angle" and about 3/4 inch stick out so it's into spray transfer. I'd start each "dot" by aiming at the bottom edge of the previous one, this way the strike is better, it is right in the root of the weld and has the thicker area of the previous spot to dissipate some heat.....
I've got some off cuts from the original build of the car, I put .040 cuts in them and the welds are starting to look OK, not like I'd brag about them, and if you need your Coke can repaired go elsewhere but I'm no longer as Nick Cave would moan, deep in the woods.
Thanks for the offer Rex but I try to use welder I can take to the job
I have an old Airco transformer TIG machine that I will give to you, works great! of course it weights about 1500 lbs
(680 Kilos) so the shipping may be a bit!
Rex
Will the voltage matter if it is upside down 
Johnboy
The reciprocal of 110 is 240 Johnboy, and the electrons flow in the opposite direction here. Just as a word of warning, when you get here we are going to make a concerted effort to F with your head, don't ask Gray or I for advice if your life, sleep or urgent bathroom matters depend on it......
