Had a Bracket on My Jet Lathe that was broke when i purchased it,I decided to do a repair, Material was a very low quality casting and very porous , i bevel ground the edge on one side with a carbide bit in a die grinder to keep contamination to a minimum , then cleaned of all the paint in the area , the paint was about .060 thick they lay it on heavy to cover the holes in the castings. Got the part cleaned w/Acetone and clamped up. Set the machine at 95 amps ,freq at about 1 o'clock on the dial and balance at about 11, gas was 12 cfm used 3/32 4043.
Had good penetration and just had to run a small cover pass on the rear. This was very porous and welded easily at low amps even though it was 1/4" thick. Did a chemical strip after the welding to get the piece completely clean, some grinding and added a little etching primer and some matching White jet paint.