Fiberglass boats are built in molds. The outside of the boat is the inside of the mold, so the outside surface is smooth and clean and finished. The inside surface of the fiberglass is somewhat rough, showing the fiberglass fabric and drips and drabs and joints and stuff.
Modern expensive boats install false panel over the entire inside of the boat, usually vinyl or fabric covered. These panels are hopefully removable so you can work on the wiring and plumbing and mildew they cover.
Modern inexpensive boats install “monkey fur,” a cheap non-woven carpet that is contact-cemented to the inside of the hull. Often the stuff is glued right over wiring and plumbing. One benefit of monkey fur is that it sort of breathes and is sort of mildew-resistant, so unless your boat is really, really wet the condensation will hold in the fur until it evaporates, without growing too much mildew.
Our boat had lots of the interior surfaces covered with sheet vinyl contact cemented to the inside of the hull. Not only is the vinyl non-breathing, but the contact cement is a food source for mildew and other living forms of death. Also, the contact cement has mostly failed and the vinyl is sagging. We do not approved of sagging on this boat.
Nancy has done most of the work removing the vinyl from our boat, but I got to help with this last push to get the stuff off the aft cabin overhead. We pulled the portlights, peeled the last of the vinyl, then scraped and used chemicals to get down to clean fiberglass.
If the boat was still in a yard and we weren’t living on it, we might have squeegeed on a coat of filler, then sanded it really smooth, but probably not. Jensen Marine did a pretty good job with the fiberglass and it’s a paintable surface.
Nancy painted the clean fiberglass with an oil-based sealing primer,
…then finished with a semi-gloss oil paint in almond, to match the ’70’s vibe.
We re-installed and re-bedded the portlights, and WHAM! A practically new boat.