I have a L99 F350 crew cab Dually 7.3 Power Stroke.
Several years ago I made a trip from Florida to Ohio in January and encountered the salt & chemicals that they put on icy roads.
I have what I'd call a flash rust on my frame that I'd like to clean up and treat without getting crazy or removing the cab or bed.
I've just had some rust repair (Florida rust) done and my painter suggested using a pressure washer, let it dry well then apply POR15 primer then the POR15 itself.
Does this sound logical?
Anything better? other suggestions? Thanks!!

 

My $.02, after several years of experience, failure, research and success on Vehicles in the Midwest with lots of Salted roads;

If you want to apply a permanent coating with the intention of having it last for several years (like POR15) you need to prep the surface reasonably well. including getting ALL scale off (to me this means, I should see at least 75% shiny metal.), and use their surface prep product. It dries hard, and plastic-like. However, if the surface isn't prepped, it will flake, and in the cracks it can hold dust, dirt, water.

If you just want something to kind of "keep in in check", invest in an annually applied product like Fluid Film, Amsoil MP, etc, and apply generously with your first big "spring cleaning" of the truck. Pop the rocker plugs hit the dust out with an air wand, pressure wash the CRAP out of those holes and undercarriage. Invest in the application gun. It really helps you to "get the gunk in there". This is especially good for boxed in portions of your frame or inside your rocker panels.

https://www.theruststore.com/Fluid-F...hoCr70QAvD_BwE

I've heard good things about wool wax, by the way. I just haven't personally used it.

Of course, this applies to Midwest trucks and winters. Florida is probably different, but I supposed if you live close to the coast, the salt-water may be bad?

Good luck!
-jb

 

Pressure wash the chassis. Grind it down as best you can or sandblast it. Apply a rust remover / metal prep with zinc and let it dry. If you use a permanent rust sealer, it must have aluminum flake or matacious iron oxide to block the oxygen. The resin is moisture activated and completely waterproof ,the metallic flake is used to block the oxygen.This system was developed by the Mobay Chemical Corporation in the mid-70s for Bridges. After the metal prep is dried apply 2 coats of the permanent rust sealer and one coat of color. This type of system will usually run thousands of hours of salt fog testing. There is no coating system that will withstand continuous exp[osure to salt brine. It is most important in the winter months to run through the car wash to get this brine off your chassis and bottom of your truck. As long as it's on your chassis the more Rust will develop. I have a 30 year career in industrail coatings which I base my information on.