How can i remove stains in the bottom of my cultured marble sinks?

If vinegar doesn't work, try alcohol. Here's a link with more details:

https://www.countertopspecialty.com/how-to-clean-cultured-marble.html

Here is a link for 3 common stains and what to do:

1. Removing Water Deposit Stains
2. Removing Everyday Stains

ref: https://www.howtocleanstuff.net/how-to-remove-stains-from-cultured-marble/

To clean with any of theses, go to an inconspicuous area if at all possible.

You need a PH neutral marble cleaner. Check out amazon.com to see what they offer.

Do NOT use the following cleaners:

• Clorox Wipes will damage cultured marble. Clorox Wipes contain bleach, which may dull the protective gel coat of cultured marble.
• Bar Keeper’s Friend should not be used as a cultured marble cleaner. It is both acidic and abrasive and can scratch and dull the finish.
• Soft Scrub is not safe to use as it is abrasive and contains bleach. Like Bar Keeper’s Friend and Clorox Wipes, it can ruin the shine and finish.
• Windex and other window or glass cleaners should not be used on cultured marble. These are not as harsh as other cleaners, but repeated use can still cause damage. When cleaning mirrors, spray Windex on the cloth first to avoid overspray onto the countertop.
• CLR, Lime-Away or other hard water stain or calcium deposit cleaners. Use a safe non-acidic Hard Water Remover instead.
• Oven cleaners and drain cleaners will cause severe damage and should not be used on or around this countertop material.
• Ammonia, which has a high pH (like bleach) and can ruin the finish and gloss.
• Vinegar should not be used for cleaning cultured marble. White vinegar (and all other types) is a strong acid. Acidic chemicals will dull or etch the surface when used as a regular cleaner.
• Hydrogen peroxide. Do not use it as It is acidic and will etch or damage the gloss finish.
• Acetone is a solvent that will damage cultured marble surfaces. It will dissolve the gel coat finish. Also, do not use fingernail polish remover as it contains acetone.
• Comet or other abrasive powdered cleaners. These will scratch and dull the finish.
• Abrasive scrub pads or steel wool will cause scratches and dullness. Do not use.

Some of these cleaners are effective when making a repair or removing a stain but may scratch or dull the resin coating in the process. So use with caution and only when really needed as part of a repair or stain-removal process.

Scrub well with a non-abrasive pad.

Get CLR it’s sold T Home Depot. Soak a cloth with the CLR and let it sit over night on the stain then rinse in the morning . If the stain is still there so it again.

You can make use of a capful of bleach together with 32 ounces of water. And just sray it directly on the surface and leave it to penetrate for five minutes. After five minutes, rub with a non-abrasive cloth, rinse with cool water and buff dry.

The one thing that I found that worked was a 1200 grit sandpaper. It is very fine and took the stains off.

Try heated vinegar with blue dawn 50/50.

Vinegar likely etched the marble causing damage which might make it harder now to remove stains. You might reach out to a place that manufactures or sells these types of sinks for further direction.

Hello Ralph, hope this helps you out, a mixture of vinegar and water removes all sorts of stains from cultured marble, including rust and water spots. Rubbing alcohol removes some stubborn stains.

Or

Steps to clean yellowed cultured marble:

1. Mix a very dilute bleach solution (1 capful of bleach added to a 32 oz. / quart spray bottle full of water).
2. Allow the dilute bleach solution to dwell on the surface for 5 minutes.
3. Scrub gently with a non-abrasive pad.
4. Rinse thoroughly with clean water.