I need to close up some holes (approx. 10mm diameter) in some 1mm thick aluminium sheet body panels. I have been practicing, by making holes of a similar size and then cutting out little discs (of the same 1mm thick material, which slip inside the hole (and which provide for no gap at the seam). I then use some copper, clamped on the other side as a heatsink. I'm using an amperage on my AC welder of approx. 35 amps and have been using 1.2mm welding rods (actually just straightened 4043 MIG wire). Using 1/16" tungsten. This seems to work well, although I have had a couple of burn-throughs.
One trick I have seen is to use some slightly thicker metal for the disc/patch piece (which will get sanded down later anyway). Perhaps that would help minimize burn-through? Any other tips for working with such thin aluminium?
Also, I naturally point the tungsten directly at the seam. Would it be better to start the puddle off to the side and then move to the seam?
Thanks!
One trick I have seen is to use some slightly thicker metal for the disc/patch piece (which will get sanded down later anyway). Perhaps that would help minimize burn-through? Any other tips for working with such thin aluminium?
Also, I naturally point the tungsten directly at the seam. Would it be better to start the puddle off to the side and then move to the seam?
Thanks!