I've heard all sorts of talk about primers and clearcoating and sanding and what have you, but what's the best procedure and the best materials and chemicals to use in order to combat rust on metal?

The application is that I'm doing a lot of fiberglass to metal body work, and I want it to last...

 

powdercoat

 

Can you explain the powdercoat process / chemicals?

 

Are you asking how to get rid of existing rust? OR how to properly protect good metal from future rust.

The anwser to #2 is easier - keep it painted. Moisture cannot penetrate paint. so as long as no metal is exposed, it'll be ok.

#1 is more complicated - the traditional method is to grind away all the rust, then prime and paint it. Or if its rusted through, then weld in a fresh metal piece and smooth, prime, paint. There are several chemicals on the market that claim to bond to existing rust and "convert" the rust into "metal". I dont know how well these work. One of the products is called POR15. Do a google search for it.

 

Okay, but is priming the best way? It's what I've always done and I'm just curious if there is a superior method...

 

the metal is stripped and prepared.

it's then ionized and a powder is sprayed on which it adheres to.

it is then baked in the oven at around 400 degrees and the powder melts over and glazes the metal leaving a beautiful finish.

Most appliances like frgs, dishwashers, washer and dryer are powder coated.

It's a tougher finish then paint.

 

Primer will absorb moisture and rust will follow. Epoxy based primer will NOT absorb moisture and will work on the metal , fiber glass combo. The good stuff is high dollar but so is the car and your time. You can not power coat fiberglass .

 

On existing panels onn cars I use Zerorust followed by 2K primer-surfacer and then a topcoat

 

Powder coat comes in different flavors. One of them is epoxy, the strongest one.

But like any epoxy product, it doesn't fare well in UV ray conditions.

 

To combat rust on metal, I use a 4.5" angle grinder and knot wire wheel. Grind it down to bare metal. Spray with POR-15's Metal Ready product. Wipe and repeat spraying until any remaining rust has dissolved into grey film and is wiped off. Spray with lacquor thinner, wipe, then primer and paint. I use Rustoleum Zinc Compound primer for 1st coat of primer then a good Krylon epoxy primer or anti-rust primer to keep the rust out. Paint your favourite flavour.

 

always use several coats of primer and finish. 4 out of 5 chemists agree "heh" that 3 coats are necessary to completely fill all the microscopic pin holes in the paint finish.

Por-15 is better but "extend" from napa, or a similar product can be easier to find. ask any car parts store what kind of rust converter they have. They seem to do a good job. I always use extend under the primer coat when I grind on my off roader's fenders.

If you do not have a grinder, "naval jelly"---as in U.S. Navy not as in belly button--- is pretty good at eating light surface rust. wipe it on, leave it a few minutes, then wipe it off. this product is also available at most autoparts stores. Follow it up with some sandpaper, then extend, then zinc primer, etc...

 

Anyone know where you can find POR-15 Metal Ready and Rustoleum Zinc Compound in bulk? Also looking for a good lacquor thinner and Krylon epoxy primer to find in bulk.

Note, I'm also asking if this stuff can be delivered out of an air compressor paint sprayer.

 

I would avoid POR-15 and use ZERORUST