Only used the poly on the canopy/hood not on the stands.
And the reason was the canopy is a tight fit so I was worried about mold ( so far none) the tank cover I only poly'd the side down/faces on the tank.
The stands get enough air that even with water changed and such they work like the can said, and still look good.
No, I did not prime anything.
I did lay the coats thick with minimal time to dry between coats. then just let them sit for a week out on the front porch per can instructions.
Only one that got three coats was the canopy with the poly.
If I had ruffed up the poly with 000 steel wool it would have covered on the 1st coat.
latest stand cut down and repainted.
still have to hang doors back on it. Didn't bother to paint the inside since the stand is only as wide as the tank.
before....
and in the house after. like I said still have to hang doors on it.
HTH
Rich
PS:
Wife says I can't use my sump in the pix behind it so I have a post over in the filter section on that and it won't be there once the tank is in place . Also need to add the top trim once the tank is on it and corner trim.