Why is my epoxy grout turning yellow?

Author: Beatrice Waters Sr.  |  Last update: Friday, August 15, 2025

Sealers and various waxes can contain polymers that can discolor over time and cause yellowing. Numerous grout types are prone to yellowing. For example, white epoxy grouts are notorious for turning yellow. Certain cleaners, especially those that contain dyes, can cause discoloration of grout.

How to clean yellowed epoxy grout?

Steps
  1. Make a vinegar cleaning solution. Mix one cup (. ...
  2. Spray the solution on the grout. Be sure not to miss any spots. ...
  3. Allow the solution to sit for fifteen minutes. You don't want the cleaning solution to dry. ...
  4. Clean grout with a brush. Use either an old tooth brush or soft bristle scrub brush. ...
  5. Rinse with a clean rag.

How do you keep epoxy from turning yellow?

You can coat the epoxy resin with a polyurethane that has ``UV protection'' as one way to prevent yellowing after the resin has completely cured (that UV-protection characteristic should be indicated on the label).

How do you remove yellow stains from epoxy?

How to remove yellow stains from epoxy countertop? Use a mix of baking soda and hydrogen peroxide. Wipe the mixture on the stain. The stain should disappear after a short time. Wipe down counters with water and spray. Use bar keepers friend for first stain. For remaining stains, use a stronger product with bleach.

How to remove yellowing from grout?

How to Clean Yellowing Grout
  1. Vinegar and Baking Soda: Create a paste with baking soda and water, apply it to the grout, and then spray or pour vinegar over it. ...
  2. Hydrogen Peroxide and Baking Soda: Mix baking soda and hydrogen peroxide into a paste, apply it, let it sit, and then scrub and rinse.

Alumilite Explains: The Science Behind Yellowing Epoxy

Why did my grout turn yellow?

Hard water exposure is one of the main reasons why grout turns yellow. Constant exposure to minerals such as calcium, magnesium, and iron causes discoloration. A practical solution for this problem is to use water softeners to reduce the mineral content.

How to bring grout back to white?

The process is exactly the same: First, mix some baking soda with water to form a paste (a ratio of three parts water to one part baking soda is usually recommended), then apply this to the grout and rinse it away after it has had time to work its magic.

Does vinegar damage epoxy?

Vinegar is an acidic cleaner, which can erode the surface of the epoxy, causing it to become dull and discolored over time. Additionally, vinegar can react with the chemicals in the epoxy, breaking down the bond between the resin and the floor, leading to delamination and potentially causing the floor to fail.

Can you reverse resin yellowing?

There is really no need to do anything to reach the final and stable color, although it takes some time. If you leave the model at room temperature, it will slowly lose the yellowish hue and return almost to its original (uncured) color in several days.

Why did my epoxy floor yellow?

Exposure to UV light is the most common reason for epoxy resin turning yellow. When UV light hits the cured epoxy resin, whether directly or indirectly, the natural process of degrading the polymers within is sped up. This photochemical reaction is responsible for more than just turning the epoxy resin yellowish.

How do you get cloudiness out of epoxy?

Try these tricks:
  1. The Wet Rag Technique: Gently rub a damp cloth over the surface. Sometimes, this little nudge is all it needs.
  2. Sanding and Resealing: If the wet rag doesn't do the trick, a bit of sanding and a thin re-coat might be the answer.

Does epoxy discolor over time?

Yes, epoxy can yellow over time and lose its original aesthetics due to certain conditions and environmental factors like exposure to UV radiation, moisture, and humidity. To minimize the yellowing of epoxy floors, several measures can be taken.

Does water stain epoxy?

Resistant to stains and water

Epoxy flooring holds up well against stains and water. Unlike wood, laminate, or other types of flooring, epoxy does not warp or water stain as a result of water damage.

How do you make epoxy not turn yellow?

Prevent Epoxy Resin Yellowing
  1. UV-Resistant Epoxy Resin: Some resins, namely polyaspartic, are designed specifically to help combat UV-exposure. ...
  2. Proper Sealing: Don't be lazy with your coats! ...
  3. Reducing UV Exposure: Limit your floor's exposure to UV radiation as much as is reasonable.

Will a magic eraser remove grout haze?

Once you've activated the micro-scrubbers inside, your Magic Eraser is good to go. Start by swiping it firmly across the desired surface. In just a few swipes, you should start to see grout messes and buildup begin to disappear!

Does white epoxy grout yellow over time?

Sealers and various waxes can contain polymers that can discolor over time and cause yellowing. Numerous grout types are prone to yellowing. For example, white epoxy grouts are notorious for turning yellow.

How to fix epoxy discoloration?

How to Fix Yellowed Epoxy Floor
  1. Step 1: Evaluate the yellowing.
  2. Step 2: Clean the surface.
  3. Step 3: Sand the floor.
  4. Step 4: Clean the sanded area.
  5. Step 5: Apply a new epoxy layer.
  6. Step 6: Allow curing.
  7. Regular sweeping or vacuuming.
  8. Promptly wipe up spills.

Will hydrogen peroxide clean resin?

Hydrogen peroxide can also be used to sterilize resin and be a resin bed cleaner. By itself, hydrogen peroxide does not damage ion exchange resins, even at concentrations approaching 10%.

Does heat make epoxy yellow?

Cure temperatures that reach 100°C (212°F) for extended periods are known to cause yellowing, and extremely high temperatures can cause epoxy to amber and form cracks. If a deeper pour is required for a project, it is recommended to pour multiple layers to build up to the desired final thickness.

Does vinegar harm epoxy grout?

A concrete base can be etched, whereas an epoxy base does NOT have this issue. Tile & Grout: While vinegar can be effective for cleaning ceramic or porcelain tiles, it is not suitable for sanded or non-sanded grout.

What does baking soda do to epoxy?

It was found that sodium bicarbonate accelerates the process of thermal oxidative degradation of the epoxy composites in the initial stage, but enhances thermal stability in the final stage.

What should you not do with epoxy?

Avoid contact with resin, hardeners, mixed epoxy, and sanding dust from partially cured epoxy. Wear protective gloves and clothing whenever you handle epoxies. If you get resin, hardener, or mixed epoxy on your skin, remove it immediately.

How to get rid of yellow grout?

Mix equal parts baking soda. and hydrogen peroxide into a paste. Apply to grout and scrub with a soft bristle brush. Wipe with a damp towel and you'll be amazed.

How to fix discoloured grout?

Hydrogen peroxide has so many uses, and it's especially good at brightening discoloured grout. Unlike vinegar, which can corrode the grout over time, hydrogen peroxide is a gentle disinfectant that is non-toxic – when used correctly. To clean grout, simply pour undiluted hydrogen peroxide into a spray bottle.

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