Looking for experienced advice here, I have a transmission housing that is made of aluminum, I want to seal the inside with paint, any one know of what type to use so the lube will not affect it ? While not automotive it does use standard differential lube. I glass blasted the interior so it could be dye checked for cracks and while I did clean it I do not want any of the media working it's way out and trashing the bearings or gears.

Thanks
Ken