well apparently the guy who owned the truck before me loved to go off roading, as a result the factory undercoating wore off and there's a lot of rust on the crossmember and frame. i'm planning on powerwashing the remaining caked mud. should i get a wirebrush bit and a drill and try to sand off the rust myself, then apply por-15? or can i just use sand paper and if i can what grit. what's the best underbody coating i can put on it? lastly if i take it to a body shop how much should it run me? thanks

 

This stuff says its better than POR-15 hands down!
Check It Out

 

Knotted wire wheel on a cheap Chinese angle grinder
would make pretty short work of things. Wear good
goggles and a thick shirt or you'll look and feel like
you lost a fight with a porcupine. The real tight bits
you might still need the toothbrush and hand effort.

I wouldn't bother with sandpaper. You'll use a lot of
it and it is not good at concave or corrugated surfaces.
Plus, you don't need to get to bright metal if you are
using POR-15, it actually wants some native oxide.

Don't know about this other stuff, looks worth checking
out. POR-15 needs two coats (the POR primer has no
UV resistance). If the Chassis Saver works like POR
but is also UV stable then that's a bonus.

 

My like, 10 month old truck has rust on various underbody pieces.

I've got a few rattle cans of flat black Rusoleum here to see if they take care of it.

 

I *think* there is a longer period of warranty for rust on these trucks than the standard 36k/3 year. That might be worth checking out.

 

The warranty on rust is in or under the paint if im correct.. If you take it to a shop they will prob. just spray it with an undercoating spray

 

the rust warranty - has to be through the panel