I have been in the automotive coatings industry for 25 years on the OEM supplier side of the business. The past 18 years as a Field tech service rep for one of the leading OEM exterior paint suppliers in the world. So I have modified, applied and adjusted many different types of coatings for many applications and processes. I will say that currently epoxy is my first choice for bare metal primer followed by urethane prime, base and clear. These preferences change as coatings technology evolves.
But I want to share my #1 proven cost effective Lazy method I have been using to restore vintage snowmobile chassis for 20 years. Obviously snowmobile chassis are exposed to water salt and dragging on the ground a lot as they cross over highways and trails.
I strip all of the paint (do not paint over paint with this process), hand wire brush any rust to the point of " clean rust". Apply a tannic acid/ organic polymer rust CONVERTOR that sprays out of a plastic bottle sprayer or a paint spray can like Total Solutions. Let it dry overnight above 60F.
Spray the Chassis with Rust Oleum self etching primer from a spray can. Pick any Brand Quart alkyd enamel color and gloss you want. Rustoleum,or XO (I do not care for the Majic paint) , any in a can you can mix and brush on or put in a spray gun . I actually use "XO Rust base white" from my local hardware store because they let me tint it to any color I want for Ski Doo Yellow or Snow Jet Blue.
To spray the base coat I reduce it with Acetone 50/50 and catalyze it with "Majic Brand" Aromatic Iso Cyanate Catalyst Hardener sold at Tractor supply. In the little green can. The raw paint to raw catalyst ratio is 16 Paint to 1 part catalyst. Once you do this do not re-use, do not dump leftover back in the paint can.
This catalyst will help the alkyd enamel dry faster and harder, lower surface tension and less porous. It will also increase the gloss slightly. Don't expect showroom shine we are talking DIY frame paint.
IF YOU SPRAY THIS DO NOT PUT 2 COATS ON! WEAR A RESPIRATOR, HIGHLY FLAMMABLE! because of EPA regulations most of these coatings are now reduced with 100% Acetone. With all of the Acetone, which is an aggressive solvent, it will re wet the first layer of paint and start to peel it off. I just use the 9 dollar Harbor freight gun for this and spray it like its a can of spray paint.
Touch up with a brush a week later.
Or reduce the base coat just slightly like 20% and brush it on. I just wanted to share that the catalyst makes a big difference in the Alkyd coatings durability.
Again, this is a cheap alternative, costs me about 30 bucks a sled and they do not rust out.
Or at least not yet. My first one was a 1969 Ski Doo and its still in the shed with no rust on it. My grown children rode it every year. Back then I got the catalyst from another source and did this as an experiment, but now you can buy it at the store.
Sorry for the long post just trying to cover all of the bases. But with paint that's impossible. Good luck.
Ray
