Well, I’ll be fluxed!
QMy 1976 Triumph Stag is booked in to have major welding done, but I was wondering if you have any advice on gasless welding sets for smaller jobs?
Dean Powell, Creigiau Ed says:
AInstead of using a shrouding gas from a cylinder, these rely on flux-cored wire. This is less unwieldy and avoids the problem of the cylinder being mysteriously empty when you want to use it. Purists dislike gasless sets – they’re often the cheapest sets available, are un-refined and can give an untidy weld. Nonetheless, we recently used a cheap gasless MIG to weld up some holes the size of a 10p-piece caused by the use of aluminium pop rivets in a steel body panel. We made flush-fitting patches and buttwelded them in on the minimum power setting. We worked our way around the perimeter of the patch in very short bursts (almost a tack weld), each burst slightly overlapping the last. We didn’t blow any holes and the welds required minimal flatting to finish them. All in all, we were pleasantly surprised and very satisfied. As usual, the crucial trick is to find the optimum wire speed. Somewhere between intermittent popping and sparking at one extreme and feeling the torch pushed back by the force of wire delivery at the other is a sweet spot, with an accompanying steady, sizzling sound. Take the trouble to find this before repairing anything sensitive or important. It’s also useful to move the torch slightly side-toside in order to distribute the little pool of weld across both pieces to be joined. Use both hands to keep the torch steady, if you need to.
The adjustable pressure on the wire feed rollers is important – not too little, not too much. As a rule of thumb, feeding the wire directly at your welding glove, the wire should slip between the rollers, rather than try to force its way into the glove.