How can I fix a chipped acrylic tub?
I would suggest a 2-part white epoxy putty. You will need to clean/prep the area then knead the putty per the mfgr. instructions. Don't use the fast-setting variety, you need time to shape the repair to match the tub (shape using knife, file, planer, sandpaper, etc.) It won't be an invisible repair but it will stick, be waterproof, and be hard when cured.