The wax ring idea just reminded me of something. The shop that first introduced me to this compound used four different Texaco compounds to rustproof a car. I believe they had a compound for the undercarriage (Type L), another for painted surfaces, and they used a wax compound that was used to seal seams and gaps by hand before spraying.
If you get any product information from Texaco, I'd like to know what the current products are for rustproofing.
