well the more ridgid coatings for the skirts i use is a ceramic coating designed to carry loads in excess of 350,000 PSI as well as lubricate at temperatures in excess of 1600°F. Cured film thickness of ".001" or less. The sub straight is etched to allow the coating to absorb then cure at suggested temperature. This coating as well as all others are applied in this manner. Doing this enables the coating to never fade or wear away.
The other coating i use works well too and is a dry film lubricant. All are applied in the same manner as to the sub straight.