I'd try for no higher than 60% RH if you can maintain that for the pre-primer prep then the time for primer to dry and cure prior to your first finish coat. Lower's obviously better but you may struggle to get below 60% unless your shop's nice & tight.

   I got my dehumidifier hooked up it seems to be keeping humidity around 50 percent. Got my hybuild primer on today will sand tomorrow. Next question after I sand and vacum surface do I need to wipe surface down with anything to get the final bit of dust. Also after wet sanding brightsides best way to clean up before the next coat.

Thanks

Larry

larry, 

the key thing on the brightside primer is that almost all of it needs to be sanded off and it is meant for above the waterline.  the primer, when done properly,  fills in  pin-holes and minor depressions....and it helps make for a very smooth surface for the paint.  for boat building, it is not really meant to be a general substrate for the paint which will adhere to epoxy just fine.

if you don't sand most of it off as part of preparing the hull for painting, it makes for a very weak substrate that also is prone to absorbing moisture...further weakening it.... and leading to a very fragile paint job - easily scraped off.

the primer is basically chalk.....so i hope that helps you understand my point above.   

when i have used it and sanded it properly, it only covered less than 5% of the surface and has lasted and worn well.   when i didn't really understand it and used it as a general primer (100% coverage before painting), my paint job did not last very long (i use my boats a lot) before i needed to resand the whole boat and do it again.

another approach to faring a hull/prepping for paint is an epoxy paste of microballoons that sands easily and fills in all the gaps and is impervious to moisture.

h