hardner in paint

Most of the synthetic (alkyd) and acrylic enamels I have seen do not require a separate hardener for drying. The field addition of an isocyanate-containing hardener in those paints is an option for increased performance. In fact, they cannot realistically be added by the jobber at the time he/she mixes up the color from mixing tints because there is a specific "pot life" after adding the hardener where the paint has to be used - usually measured in only a few hours. I have no knowledge about John Deere paint. If they don't list it on the can label as a possible field additive, they probably don't recommend it. I suspect there could be a couple of reasons for that. One would be they don't market a specific hardener for it. Another would be the market for dealer-supplied paint is most likely individuals and the vast majority of individuals, homeowners, weekenders and other DIYs simply do not have the personal protective equipment to safely deal with isocyanate-containing materials. All the hardener cans in PPG and DuPont that I have seen carry the "Not For Sale To The General Public" caution, along with a lot of fine print regarding safety. Matter of fact, I am surprised that such hardeners have not been effectively banned outside of professional body shops. Here's something from Saskatchewan on the subject. Don't let the trial lawyers read this :o).

Rod