Q. Andy - I have some aluminum auto trans cases that have been "ventilated" but are salvageable. What rod would work best with my TIG welder, and what kind of surface prep do you recommend prior to welding? (Submitted by: Scott Currie from Evansville, WI)


A. How bad were they "ventilated," and do you have the pieces to fix them or will you be making a patch from other material? In either case, cleaning will be critical with oil-laiden castings. Get a good aluminum cleaner from your local distributor. Stay away from petroleum-based solvents as it will only make your aluminum look clean but still have the contaminant properties of oil. If you are in an area of the casting that is not critical to strength, a 4043 filler will probably be the best choice of
filler. It will "blend" better with the multitude of casting materials.
Casting quality will play a part in the ability to weld, also. If it is a poor
casting, you will have to weld some then clean again as the contaminants
start to pull up toward the heat source.