Should I coat/rustproof floorpans?


Cat&wife post starter
May 26, 2001
Tracing a leak from the cowl area and also replacing the rug. Obviously the water has caused some rust. The rust is only surface rust, but some parts are a little more surface than others. Everything is solid. Should I coat it with anything? POR15? Rustoleum? I'm a little hesitant to coat it, but in reality I don't know why.


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I would, sand what you can, and POR 15 the rest, or whatever rust conversion chemical you prefer to use.
I have used KBS Coatings on many projects and it works. I did a set of wheels on my utility trailer that sits outdoors 5 years ago and they are still rust free. They ship by mail too.
Have never had success with POR.
Even on bare/rusty surfaces it peeled off in big pieces.
Wire brush, vac clean and dry, Rustoleum Pro.
Mostly it's in the prep.
  1. Physically remove as much rust as you can - any way you can, wire brush, sand, scrape all the flakey crap & rust swollen metal off.
  2. Next I used EVAPO-RUST GEL & liquid. Repeated applications for heavy corrosion.
  3. When complete it should leave a dark film, The coating on the metal is water soluble & can be wiped off.
  4. NOW use POR or Rustoleum primer and follow with paint if you want.
A lot of putzing and elbow grease! But you get durable results.

My 2 cents.
So I decided to use the Corroseal to chemically treat the rust then going to top coat with Rustoleum Professional. So I wire brushed the rust and the plot thickened. I did try to put my finger in the holes to make them bigger but they seem pretty solid as they are. What is my best option? JB Weld? Epoxy? Replacing the floor pan is NOT an option.
Clean to good metal with a carbide burr and spot weld em with a mug welder. Or after cleaning with a burr, treat the edges with enamel paint and then use a fiberglass patch. I spot welded my small holes and used fiberglass for the bigger one. I fiberglass patched from the bottom of the car. Realistically I should’ve welded a new floor pan in but. I’m a college kid on a budget and don’t have the time or money to do that. I treated all the rust with coroseal, painted that and then patched the hole. I just used a nice mig welder for the pinholes I had.