Pratt&whitney aircraft etching primer. Shermin williams makes it but I don't know the name. Also after it flashes you have to cover it with a primer or sealer. If not you'll have to scuff it GOOD before you apply anything later. This is a commerical aircraft product and offers higher corrosion
resistance than regular automotive products. I used it and NEVER had a rust problem. BTW try to spray after your repairs cause it's tuff to get off. also it makes a good guide material cause it puke green. I used DP-90 lf and with the lead out it doesn't stick as well.
Pratt & Whitney made air-cooled reciprocating aircraft engines for WWII airplanes. Pratt & Lambert makes paint. Pratt & Lambert is a very good quality product and though, perhaps in some areas, is sold by Sherwin Williams, it is a far superior product. Pratt & Lambert is not an aircraft paint, however, as I used it when I used to paint houses, professionally. This said, maybe Pratt & Whitney diversified into aircraft products other than engines, such as paint. I'm always amazed by the extent of my ignorance.