To install a bathtub liner, scrub the surface of the bathtub with denatured alcohol to remove scum and oil deposits, and cover the tub surface with liner adhesive. Apply sealant to the outer edges of the tub, fit in the liner, and then caulk the edges of the tub.
- Clean the bathtub, and unscrew the knobs
Soak a rag with denatured alcohol, and use the soaked rug to scrub the tub's surface to remove soap scum and oil buildup. Loosen and remove the knobs from the tub fixtures.
- Apply adhesive, and seal the tub
Smear a liner adhesive on the bathtub's surface to avoid any gaps when the new liner is installed. Then, seal the outer edges of the tub to block water and other substances from entering the tub.
- Fix the liner, and apply caulk
Fit the liner onto the bathtub, and use a utility knife to cut the liner as needed to fit the tub. Press the liner against the tub's surface, smooth the liner with your hands to eliminate any air spaces, and replace the knobs. Caulk the edge of the tub to keep off water and give the tub a fine look. Let the liner dry for a day.