Should I sand the final coat of paint on my plane? I painted with latex, and plan on using poly-u to fuel proof. Thanks.

Latex? As in house paint? You're kidding right?

No you shouldn't have to. Just make sure ya give it a few days to REALLY dry before applying the poly.
Make sure ya post a pic if ya can.

Tom,
Nothing wrong with using Latex as long as you use a fuelproof clear coat afterward. The clear has to be compatible with the Latex of course.
Dennis-

PAINTED MY SUKOI COWL WITH LATEX AND DIDN'T HAVE TO SAND IT BEFORE THE CLEAR COTE BUT I USED MINWAX POLY CRYLIC WHICH IS THE CLEAREST YOU CAN BUY FUEL PROOF UP TO 15% NITRO BUT LATEX IS ALREADY GAS PROOF IF YOU ARE RUNNING GAS

Guilty!
One way or another I ruined the dope(paint) mixture. In my frustration, I read an article on latex and decided to try it. The process is VERY easy. I hope it lasts! The following is my work in progress. The wing will be yellow and the trim is yet to be determined. I appreciate your advice, thank you.