Boat finish

What is the product called to get a smooth finish over fiberglass or carbon fibre. I am attempting to make my own seat and want a smooth finish so my bum will slide as I rotate on the seat

also am i better of just using fiberglass or carbon fiber to make a strong seat i never used carbon fiber is it the same process as fiberglass?

Are you asking about gel coat?

Most of the Kevlar, and carbon fiber boats just make a seat with a epoxy finish. Their process is called vacuum bagging. That means a piece of plastic is vacuumed down to give it a smooth finish.

Most gel coated boats use the same process for the same results.

If you have to sand it down, you can used a polishing compound to smooth it out, varnish it, or use a spar urethane as a finish.

Some racers I know use 303 by DuPont to give it a waxy finish that allows more torsional rotation, but both varnish and spar urethane can get really slippery when wet because of a glossy finish.