Preventing rust

[padlin]

Spent the weekend installing a 5th wheel hitch in my truck. The job required drilling 4 holes through 1 wall of the frame and 10 holes through the bed, all 1/2". For anyone who has drilled through their vehicle, what have you done to prevent the raw edges from rusting? I live in New England, snow and salt are common.

 

[Vicki A.]

I know that one person here, had the holes cut first and then did a spray-in bed liner. When he was ready, the hitch was mounted. Made a lot of sense to me.