I would pull the sound insulation as well, and apply the liner directly to metal. Then, put your sound insulation, and whatever else you have, over top of it. Make sure you give it plenty of time to cure before putting anything else on it.

 

Check out my thread, I tested all the spray and roll on bed liners. The best one I found was herculiner. I used they for my bed and the only thing that went through it was a 600 pound axle. But the thing about herculiner is it's the only roll on bedliner that you can touch up (because it sticks to itself).

 

If you still have signs of rust after sanding (its not all completely shiny), I'd use a rust converter first - like Carroseal or equivalent. Follow the directions, and make sure give it time to setup.

 

Either that, or use something like POR15, or Chassis saver paint, and call it a day. You can paint right over the rust, and once that stuff cures, it is basically bullet proof.... No need for anything else. The Bedliner, on the other hand, will likely act as a sound deadener as well. (it goes on thicker.)

 

I want to paint my frame with one of those, but don't know which one

 

If you go with the paint products, call the manufacturer and ask how to cover it. If I remember right, the trick with POR15 was to prime over it before it dried. You let that stuff go hard, and you'll be hitting it with heavy sandpaper to get the top coat surfaced enough for other products to stick over it. But don't trust my poor memory, call and ask - they're happy to help. I've used both POR and ChassisSaver, they pretty much do what they say... but the cleanup is tough, and get it on your hands and it'll be on there for a few days while you wait for it to wear off. There are a couple tricks to dealing with the cans - the product tends to fuse the lid to the can. Either poke a hole in the top and use tape to seal it off, or use kitchen plastic wrap between the lid and the can.

Carroseal on the other hand is water based, very easy to clean up.... but its a completely different product, and is really only a primer once cured, and that takes at least 24 hours before you can topcoat. I've switched over to using Carroseal.... yeah, maybe I'm getting lazy and more patient...

 

I like POR and Chassis Saver as a top cost for frames I just don't know which one I'm going to use

 

I went with the chassis saver, as it was about a third cheaper than POR 15. I used it on my 72" mower deck when I rebuilt it. Did the belt well, and the underside of the deck. That was 4 or 5 years ago now, with only doing ONE coat. The stuff still looks exactly the same as it did when I applied it. It is incredibly hard as well, I couldn't even sandblast off the stuff that got where I didn't want it. I had to use a grinder......

Get it on your skin, it's going to be there for a while. Get it on your clothes, it's going to be there forever. Using plastic wrap between can and lid is pretty much a requirement, if you want to be able to re-open the can. Also, pour a layer of thinner on top of the remaining product, to prevent it from curing in the can. (and don't shake it up. )

 

Is it glossy? I want high gloss. When I losing the truck this year after I paint my Hemi Cuda I am also doing the frame of the truck