Hi all. Working on a BMW m3 and have some small repairs that need new metal welded in. Mostly around grommets that have rusted through. I ordered a Clarke mig 105en and some 1.2mm mild steel sheet from frost and started practicing to the point I was happy enough move to the car. Starting in the wheel well, I cut out the bad metal, cleaned up both sides around the cut to about 50mm from the edge and then used the 1.2mm sheet and created a repair piece, fitted well with only a couple small gaps. I tacked into place and everything was fine, was more than happy and then that's where it went Pete tong! Attempted to do the stitch weld process so as not to distort the panel and it just kept blowing holes, between both the new and old metal. At this point I changed wire from 0.8 to 0.6 and still the same, checked ground, still the same. Then I realised they had sent me a Clarke mig 106 en and the range was 40 to 100 amps so the lowest was too high! Sold it on as I had used it and got a Clarke mig Pro 90 instead. Started at it again yesterday, cleaned and grinded everything down, some is OK but lots of pin holes. Using 0.6mm wire, hobbyweld 5 and lowest setting it's still blowing through instantly. Even trying some folded copper pipe behind it but it's a mess. Any advice is appreciated. Thinking of cutting it out and starting again as maybe I didn't get enough of the bad metal out.