How do you remove heavy rust stains from a bathtub? Use baking soda and vinegar.
Apply it to the rusty surface with a scrub sponge, and let it sit for an hour. When you rinse it off, the rust should be gone, though, for more severe stains, you may need to repeat the process.
Can you use CLR on fiberglass tubs? Yes, CLR is found to be safe on fiberglass. Always spot test first in an inconspicuous area. Begin with a mixture of CLR and water and progress to full strength if needed.
How do you remove stains from a fiberglass tub? Before you give up on trying to scrub away the stains, try the cleaning process Home Depot recommends for tough stains on fiberglass: Smear on a paste of baking soda and water, and cover that with a towel soaked in vinegar. Wait one hour, then rub with a cloth or sponge. Rinse. Wipe again with a clean microfiber cloth.
What is the best rust remover for bathtubs? While food-grade distilled white vinegar can be used, cleaning vinegar with a higher acidity is better for tough rust stains. For weekly cleaning of sinks, tubs, and shower walls, spray the vinegar on the rust stains. Use a scrub brush to clean the area and then rinse well.