Thanks to all for the info!
Now I'm wondering if I should use a hardner at all. We have little ones visit frequently and I sure don't want them even remotely exposed to something as described above, if I can help it.
The truck cab, fenders, box and end gates will be painted by a pro. I am wanting to do the black sheet metal engine bay pieces and cab interior parts myself. All those pieces are or will be removed for painting. It appears from having used Rustoleum without alteration to paint the frame some 18 months ago, that stuff might be hard enough without additional hardner. Since then, though it has not seen daylight or been tested. Anyone have experiences to report, just going that route for the interior sheet metal parts?
