Painting rust prone areas

[Bwana]

Is there any reason not to paint rust prone areas, such as the box section in the front wheel wells/A pillar area with one of those rust conversion paints from, say, Rustoleum? Other than having the body guy hate you when you finally get it all repaired?

It's generally in good shape but obviously rusting. I've scrapped and vacuumed out all the loose stuff, any problem in painting it? I figure it would slow the rust down here in Houston

 

[Stevehose]

I sprayed everything with Penetrol which gets into the rust/metal and treats/encapsulates it, not just covers it with paint. Available at Home Depot by the gallon. I have sprayed it everywhere I could get the wand into.

 

[m_thompson]

I used a conversion chemical to turn the iron oxide into iron phosphate, then sprayed on a zinc rich primer, then a coating of Rustoleum. As long as it doesn't get wet that should slow the rust down a little.

 

[Sven]

My experience with those rust conversion/removal chemicals is that they work great for surface rust conditions as prep for priming on good lightly rusted metal, but will not cut through the thicker/deep rust that we usually find in the coupe's rust prone areas. Unless you grind/sand/cut or acid dip you are not really achieving much besides encapsulating the rust.

 

[m_thompson]

My experience with those rust conversion/removal chemicals is that they work great for surface rust conditions as prep for priming on good lightly rusted metal, but will not cut through the thicker/deep rust that we usually find in the coupe's rust prone areas. Unless you grind/sand/cut or acid dip you are not really achieving much besides encapsulating the rust.

In my case I had the fenders and the attaching sheet metal off at the time. I sand blasted, wire brushed, and ground the rust off before applying the conversion coating and paint.

 

[Bwana]

My experience with those rust conversion/removal chemicals is that they work great for surface rust conditions as prep for priming on good lightly rusted metal, but will not cut through the thicker/deep rust that we usually find in the coupe's rust prone areas. Unless you grind/sand/cut or acid dip you are not really achieving much besides encapsulating the rust.

True, but isn't encapsulating the rust a way to stop it from spreading by cutting off the O2 supply? I know that if you just paint over a rusty area of anything made of steel it will eventually rust back thru but I'm hoping the conversion stuff will mitigate that. I'm thinking that in the conversion process it seals the surface where as the paint in simply painting it is porous enough to let the air back in.

Any chemical engineers/body men out there?

 

[Nicad]

POR 15 has been on my Corvair floorpan for over ten years now. Still looks good. Wear a respirator if you go that route.

 

[afeustel]

I have been reading up about Fluid Film. Has anybody used it? Looks like a decent product that may have applications inside of doors and rockers, possibly with an annual application. There are a lot of users and comments out on the net with what seem to be reasonable results. It reminds me of the stuff BMW sprayed all over the E30 M3 (KOSMOLINE), but this stuff does not harden.

http://www.fluid-film.com/applications/automotive/


Going to purchase a few cans this afternoon and try it out inside the doors of the Bavaria and a few other places to see how it holds out.

 

[Nicad]

I have used Fluid Film for several years on stuff around the house. I think it sticks quite well. For internal panels and car applications I have been using either Rust Check or Krown Rustproofing annually for the last 30 years on my main vehicle.


http://krown.com/


http://www.rustcheck.com/