This is the real deal, military spec chromate (not the new version with the good protective chemicals removed). You do not want sniff these poisonous chromate fumes.
Sandblast strip on the frame.
Sprayed with zinc chromate - rust prevention galvanizing sealer.
Kids don't spray this at home!
Take your frame to a pro for this type of spray work.
Next step completed in the frame work. Factory black paint color sprayed over zinc chromate. It’s now ready to build out. Overkill to use this type of frame coating? It's a choice: crawl under the car and spray rust stop on the frame every year or add preventive when you do the frame up. Especially important, if you're living/driving in wet environments.