Q.I bought a house that the bath tub has a lot of built up stains, I am guessing they are dirt, and oil from taking a shower. The bath tub clearly has never been cleaned. I have tried vinegar, CLR, acetone, but nothing works. HELP
(B.D, 16 April 2009)
A.Unfortunately, the key to successful stain removal is rapid action so any stains or marks which have been left for a long time will often be deeply ingrained and probably impossible to remove.
Having said that, the other thing to remember is that some stubborn, old stains require many repeated treatments before seeing any difference so it may be that you simply need to persevere and tackle the stain again and again with the stain remover.
Vinegar and bleach are both effective stain removers and should work on most stains, especially if they are just dirt and oil. Leaving the stained area to soak overnight in the vinegar or bleach may help. (Note: bleach is a very powerful chemical and should be treated with care and caution).
Another thing you could try is borax powder which can be bought in hardware stores. This can be sprinkled directly onto the stains and then scrubbed with a plastic brush, then left for at least 30 minutes before rinsing away thoroughly.
A paste of borax powder and lemon juice can be very effective: gently rub this onto the stains and leave it to dry, before rinsing it away. Alternatively, a paste made from cream of tartar (a mild acid) and water or cream of tartar and hydrogen peroxide can also be tried. Be very careful, though, if using these solutions on a fibreglass bathtub and make sure that you do not scrub with an abrasive.
As a last resort, you could also try hydrochloric acid but be warned: this is a very powerful, caustic chemical which is normally only reserved for very old, stubborn stains. Never leave it on for longer than the directions say and take great care when using it, as it can eat away at the porcelain itself, producing a rough surface which will stain even more easily in the future.
Another thing to think about is whether the stains could be due to rust, as opposed to just dirt and oil. Water in some areas may be high in iron and thus are likely to leave orange or red residue. If this is the case, then commercial cleaning products made specifically to target rust are your best bet. Again, you may need to treat the stains with several applications.