What Causes Rust? How Do I Remove Rust In A Product? KOHLER | Bathroom Sinks | Bathroom KOHLER | Toilets, Showers, Sinks, Faucets and More for Bathroom & Kitchen

What Causes Rust? How Do I Remove Rust In A Product?


What Causes Rust? How Do I Remove Rust In A Product?

When rust occurs on a product, it resides on the top surface. It is caused by some type of metallic particulate which has oxidized on the surface and turned to rust. It is good to remember that glass (enamel), vitreous china, stainless steel or Vikrell cannot rust on its own.  There would be metallic particles introduced on the product to begin the rusting process. Fortunately, surface rust can be removed by using various rust removing products. KOHLER recommends  "Super Iron Out Rust Remover".  It comes in a crystal powder form and is sprinkled onto the rusted area. A chemical reaction removes the rust. For heavily rusted situations (like a tub bottom), a second or third application may be necessary to completely remove the stain. It should be noted that any metallic particulate which resides on the enamel surface, will need to be removed, otherwise the rust will return again.  

Dish rags or other cleaning utensils may have been left on the deck or basin. Rubber mats left in a sink will allow soap and hard water deposits to form in the grain of the sink. The use of abrasive pads, even sparingly, will allow rust to get into the grain of a sink.  Hard water in the household may also account for rust stains. These rust spots can be removed, if not prevented, by regular use of a Scotch Brite pad and stainless steel polish.

Drain Rust:  Drain rust occurs when caulk used to install the drain deteriorates and develops fine cracks and gaps. Water seeps underneath the caulk, oxidizes, and forms a rust line along the opening of drain. If left unattended, the rust can affect the enamel finish, causing corrosion, cracking and chipping. Drain rust is caused by the deterioration of the caulk or improper installation and is not the result of a manufacturing process.

Stainless Steel Sink Rust:  Stainless steel is a durable material that can rust in certain conditions.  If rust appears on the underside of the sink it is likely due to the contents of the cabinet it is in.  Fumes from many household chemicals can rust a stainless steel sink.  Do not store open containers of cleaners or chemicals such as bleach, acids, salt, lye, toilet-bowl cleaner, drain cleaner, or hard water stain removal products under your sink. 
If rust appears on the inside of your sink it is likely a result of the chemicals being used in, or around, the sink.  Similarly do not use cleaners with bleach to clean your stainless steel sink.  Even if these cleaners are used for the counter tops adjacent to the sink, the overspray can land on the sink and cause rusting.  Please consider using non-bleach alternatives or rinsing down the sink after using them. 
When rust does appear it is typically only surface rust and can be removed easily with the right cleaners.  KOHLER recommends Bar Keepers Friend MORE spray and foam cleaner and Autosol®.  Apply the cleaner with a nonabrasive cloth or sponge, working with, not across, the grain.  Do not use steel wool, wire brushes or abrasive sponge pads. Use only non-scratch cleaning pads.  Rinse thoroughly and towel dry all surface after cleaning.

Rust around the rim of a Cast Iron lavatory:  Similar to drain rust, rust around the rim of a Cast Iron lavatory occurs when the sealant is compromised, forming fine cracks and gaps. This can occur from age, cleaners used, or improper application during installation. Water can seep underneath the caulk, oxidize and form rust along the rim. If left unattended, the rust can affect the rim of the lavatory, causing corrosion, cracking and chipping. Rim rust is caused by the deterioration of the caulk due to age, cleaners used, or improper application during installation.

The corrective action to remove rim rust:

1. Remove existing caulk or sealant. Take care to avoid countertop contact with rust remover.

2. Clean affected areas with Super Iron Out Rust Remover, Whink Rust and Iron Stain Remover or Bar Keepers friend.

3. Apply coating of Rustoleum to rim area.

4. Apply touch-up paint (Kohler part # 500306-**) to affected enameled areas. Let dry between layers.

5. Apply bead of silicone sealant around rim area.

6. Immediately spray with soapy water to prevent the silicone from prematurely curing.

7. Run soapy finger around perimeter of sink in siliconed area to compress silicone in for proper seal.

8. Remove any excess sealant or residue with soapy towel.

9. Let the sealant cure for a 2 hour minimum then remove soapy film with warm water


The corrective action to remove rust spots, drain or overflow ferrule rust is as follows:

1) If involving the drain or overflow ferrule, remove the drain/ferrule. If the rust does not involve the drain or overflow ferrule, continue to step 2.

2) Thoroughly clean the affected area with Super Iron Out Rust Remover, Whink Rust and Iron Stain Remover or Bar Keepers friend. If the ferrule has been affected by the rust, a new ferrule will need to be ordered. Please see the online service part store to order part number 85121-**.

3) Reinstall the assembly, taking care to completely seal the drain flange or overflow ferrule with plumbers putty or 100% silicone sealant.


The corrective action to remove rust from Cast Iron tub bottoms:

Products to Use: Whink Rust & Iron Stain Remover, Super Iron-Out Rust & Stain Remover, Naval Jelly

Scrubbing Products to Use: (3M) Cleaning pad, Stiff Bristle Brush

*When working with these products using hot water, they do tend to smell very strong. Make sure the area you are working in is well ventilated; Kohler recommends to turn the bath fan ON. You might also consider having the person that does the cleaning wear a respirator.

**If cleaning rust from a crack in the enamel, you should apply super glue over the cracked area in the enamel. Let the Super Glue set for at least 12 hours and then wipe off. If application occurs on the gritblast pattern, carefully use a razor blade to remove the glue skin. This will seal the crack from future water penetration.


1) Run HOT water into tub, let stand for 15 minutes.

2) Drain water and apply rust remover directly to each stained area. Let stand for 10 minutes.

3) Scrub each area with recommended scrubbing product.

4) Rinse with HOT water and inspect the non-slip area for rust stains.

5) If stains are still present, repeat steps 1-5 for a 2nd or 3rd cleaning process.

7) When rust has been removed, rinse thoroughly. This last rinse is very important to remove the metal particles that were on the non-slip pattern. If a good rinse isn't done, the stain may come back.


Examples of rust



Please also click on the link below for the recommended care & cleaning guide for your specific product.

KOHLER Care & Cleaning Information

STERLING Care & Cleaning Information

Click Here For Maintenance And Service Parts



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Topic Information
  • Topic #: 5641-648
  • Date Created: 12/08/2009
  • Last Modified Since: 01/17/2018
  • Viewed: 7372