Re: How do you Waxoyl [or Other] treat Frame rail
I diluted some anti-rust primer paint and poured it inside the inner sills before I welded the tub of my TR3A back together again. This was in 1988. I finished it all and then sprayed diluted Waxoyl into the frame from the rear end which was open and through the small hole in the front end.
The frame and all under body parts are painted black with two-pack DuPont Imrom. I did not apply any Waxoyl or other underbody protection over the paint.
In the 16 years since then, I have driven 94,000 miles and there is still no rust - anywhere. During that time, I guess, I have washed the car about 75 times and driven it only about 4,000 miles in the rain.
When people drive their LBCs about 1,000 miles a year, I don't know why they are so concerned about new rust developing.