How to Redo Resin on a Hot Tub

Drain the water from the tub and then turn off the electric power and the water supply to the tub before you begin redoing the resin gelcoat.

Clean the tub with a scrub brush and a mild detergent to remove any dirt or debris. Rinse the tub out with clean water after cleaning the surface to remove the detergent residue. Allow the tub to dry overnight.

Remove any remaining gelcoat from the tub with a palm sander and 200-grit sandpaper. Attach the sandpaper to the sander, and then run the sander over the surface of the tub until you’ve cleared away any of the shiny gelcoat covering from the tub. Wipe down the tub after removing the gelcoat with a piece of cloth dampened with acetone.

Use a screwdriver or wrench to remove any of the tub’s fixtures that you can pull off the tub. If there are any that cannot be removed, then cover the fixtures with masking tape to avoid getting the new resin coating on them.

Search the tub’s surface for any scratches or gouges. Sand the damaged area with 80-grit sandpaper to abrade the surface and then wipe the area with the acetone cloth. Fill the damaged area with a resin based pool putty, using a putty knife to stuff the putty into the damage and to scrape over the surface of the patch to level it off with the surrounding tub surface. Allow the putty to dry to the touch and then sand the surface with the 200-grit sandpaper so that the surface of the patch matches the tub’s contours.

Wipe down the surface of the tub with the acetone-dampened cloth again to remove any residue from sanding.

Roll a layer of vinyl ester-based resin over the surface of the hot tub. Cover the walls of the tub with the resin and then cover the floor. Wait for the resin to dry to the touch before continuing.

Cover the resin with a layer of swimming pool gelcoat, again rolling the coat over the walls before covering the floor of the hot tub. Allow the surface to dry for three hours and then place a second coat over the first. Wait another three hours and then apply a third and final coating to the hot tub.

Wait 24 hours for the gelcoat to dry completely, and then remove the masking tape from the fixtures still in place and attach those fixtures that you removed. Wait about two more days before refilling the hot tub and using it normally.