exterior plywood finish process

[Marcos989A]

New project needs completion in the next 3 days.
All products purchased new of my choosing. I need advice on these.
Goal: construct\install a truck (Ford E-350) cab-back that will see 100% weather for <1 yr. Finished product appear white, semi-gloss.
According to my understanding (after proper preparation) step #1 -epoxy the edges well. 
It's the next step I am unsure of.
At what point do I apply the paint? Before what and after what?
I need to pass a vehicle inspection, it needs to look good.
A cargo box will soon be installed so completely temporary.
Thank-you, btw.....64.....some woodworking in my past yr's ago.

[fredhargis]

I'm not sure I understand everything, but if it's temporary I'd paint it with an oil based primer and then top coat with a 100% acrylic exterior paint. The oil based primer will slow things down....but it will insure the finish lasts. It will probably take at least a day to dry enough to top coat.