automotive rust question

[Fisherman]

A coating that dries hard like bed liner paints can hold moisture in and rust the metal under the paint if the surface is not prepared properly. Commercial rust spray products that stay liquid and spreads over time was tested a few years ago by university students to be the best, the disadvantage is it needs re-application at least once a year.

Corrosion free is good for a year and a half so you get three years of product for the price of two.

[warpipe]

Another vote for fluid film. I've had my truck Krowned for a few years but after having access to a buddies hoist it looks like they've missed areas. I bought a Woolwax gun with all the attachments and buy the Black Fluid Film from Princess Auto. It goes on nice and heavy yet the overspray creeps into the nooks and crannies. I have a 2012 Silverado and removed the box to replace the fuel pump and not only did all the bolts come out easy the underneath and frame is in great shape.