primer steps????

[Satatic]

If you use poly primer it does need sealed. Filler and poly primer are the same.
Epoxy
filler
epoxy
poly-primer
sealer/epoxy

You can do:
epoxy
filler
poly-primer
sealer/epoxy

But no need to chance it.

My personal opinion is it better than high build urethane primer. I like to be able to do all my blocking start to finish without worrying about burning through. If I use urethane high build I am pretty much guaranteeing that I will re-spray 10 times. Poly I can put on 3 coats and start out with 120 and go up to 320. Put on 3 coats of epoxy and wetsand with 400 and ready to topcoat.