Hey guys just want a clear answer on some questions please, I’m doing rust prevention on my 1983 ford f100 and I want to use undercoating to stop some rust. What’s the process of undercoating bare steel?
Can I paint over the undercoating? (CarQuest made spray paint)
Do I have to primer it? (Self etching gray primer from autozone)
Should I be doing anything different?
I got raptor undercoating, the light desert tan spray paint and primer, What is my process??

 

Pics of rust might help.

This is what I have found. Everyone and every company (e.g., Eastwood, POR, ....) has their own take on how to deal with rust. The companies are all out to sell their snake oil; the vast majority of guys making recommendations don't really have long-term results.

If you post pics, I will tell you my take on dealing.

Roy

 

Under ccoat DOES NOT STOP RUST!!
It just covers it and not a good job at that.
Yes would be nice to see the rust to say the best way to go about holding it off from rotting the area.

Any holes cut the rust out, must go 2+ inches out from where you see the holes to get it all, and weld in a patch or replacement panel.
If no hole and just pitted I have used a acid It is the best to kill rust as it east into it and turns it black and then you do your normal body work.

On the under side of my cab, 81 F100, I did 2 coats of roll on bed liner to protect it. I did not prim or paint before but might have been better do so?
I also did 2 coats of roll on bed liner on the top side floor, again not primer or paint.
Rest of the body had a lot of body panels replacement and if it had surface rust was treated with the acid before body work, primed & painted.

No under coat anywhere as it has pours and water will make it's way to the metal and why I will not use it.
There is 1 member in the 80 - 86 truck area that uses Fluid Film to coat the inside of panels and frame to hold off rust.
It comes in spray cans or brush on and think clear or black, I have not used it and do have a spray can of it I got somewhere on the shelf.

I do drive my truck but does not go out in snow (we dont get it but do ice) when salt may be down but does go out in the rain if I need to use the truck for weekly trash run.
Truck has been on the road for 6 years now and has over 28K miles.

So in short treat rust with acid, body work. prim, paint and if you want fluid film.
Dave ----

 

I my self world prep bare steel with 80-120 grit and get your self a good epoxy primer which will run circles around etching primer and give it a few coats then apply some rust proofing... lanolin based is probably the best.