Stringer,
Are they disassembled? In other words, can you get to both sides?
I have repaired a lot of older ones in my area and find that several work overs with acetone followed by a stainless wire brushing is a good start. Then, I go over it from both sides, when possible, with the GTAW torch. Back over with acetone and brush. Then, a light groove on the inside with the die grinder and weld the first side, usually the inside that can't be seen later. Then, go to the outside, grind and weld. That weld usually comes out pretty clean. Finish off the outside, then go back into the inside and try to clean it back out somewhat then weld again.
Sometimes with the cast it helps to run a 'buttering' pass down each side first and come back through with the bridge. Helps with both impurities and cracks. Used to do the racks for the bowling alley. They were so much fun because of all the thickness changes and the alloys. Finally had one that totally defeated me. Could not fix it no matter what I tried. Cracks just got worse.
I agree, I always had better luck with the 5356.
Good luck taming the shrew.
He Is In Control, Have a Great Day, Brent
Thanks, Brent. I haven't tried acetone. I can get to both sides (using shorty back cap) and etching with the torch on both sides is something I haven't tried. I clean both sides with die grinder and take the crack out. The contamination is all coming from the porous aluminum casting. I was hoping for some sort of chemical and cooking cure but can't find anything. I butter it until it messes up, then grind out and start over. Lots of patience burned up in these things.
Nothweldor, I will see if I can find that alloy in TIG rod, thank you for the tip.
I used to repair old Harley casings for a friend of mine and went through the same thing. A lot of stripped out bolt holes that I ground out completely and built back up. The ww2 era motors were the worst. He pulled of one of the jugs and left the other side still complete. Halfway through a repair that side turned over like it wanted to start. Had to change my tungsten after that. Sometimes these type of projects require more patience than super welding ability. Its still a lot of fun though.
I have been using 4943 since this past summer on horse trailer repairs. Works very well. Hobart is the only source, so the LWS told me.
Griff
I wish I had some helpful insight on to how to fix this. In my experience trying to fix aluminum fuel tanks, sometimes it just wasn't worth the effort. You are basically trying to weld on an aluminum oilite as years of use at temperature have impregnated the metal matrix with oil.
My only guess would be to try something like vapor or steam cleaning and see if a vendor can pull any more of the gunk out. Perhaps an anodization vendor has some tricks like acid etching that may attack the oil and not the aluminum. Problem is it's the whole metal thickness or at least a good amount that is contaminated.
Topic Welding Industry / General Welding Discussion / oil soaked pre-war cast aluminum Indian casings
Brent,
