Compounding 2K paint

[Tigerfeet]

I've sprayed up my C15 tinware with 2K paint (the air-dry variety - no Isocyanate).
How long should I leave it to harden before compounding?
Could / should I start with 2000 wet and dry, before compounding - to get a head start?

[scifi]

I think with most of these paints there are two figures worth remembering..
Up to 20 minutes, for the application of a second coat.
Over 24 hours before it is hard enough for sanding. 

[Bigsingle]

I think  some 2k paint have respray times and if is a short time it uses a chemical bond but if you leave it a lot longer the sanding is required to create the mechanical bond , another thing I found out is some base coats that are sold as 2k but they are actually  just the paint and the thinners, the difference is that they are "2k compatible" for a good quality clear coat , clears , hardener and reducer /thinners , or the spray bomb option with the activation button for the hardener . Cheers