Amine blush is a waxy, cloudy, or greasy film that can form on curing epoxy. It happens when the curing agent reacts with moisture and carbon dioxide in cold, damp air. It weakens the bond to the next coat. It must be washed off before recoating.
Why Amine Blush Matters for Your Floor
You’d rarely notice amine blush on a finished floor, but it can cause real problems between coats. An epoxy floor usually goes down in layers, and each layer needs to grip the one below. A blush film can act as a bond breaker between those layers, a bit like trying to tape something to a greasy countertop.
If the top coat goes on over blush, it may peel or delaminate later. Blush can also leave the surface looking dull or blotchy, and it can cause yellowing and weaker stain resistance.
What Amine Blush Looks Like
Amine blush can feel sticky, oily, or waxy to the touch. It may look cloudy, milky, or hazy, with less shine than the rest of the floor. It sometimes shows up as greasy white spots or salt-like crystals. It can be hard to see, so contractors often check by feel or with a simple test before recoating.
What Causes Amine Blush
Blush forms when epoxy cures in cold, damp conditions. The biggest risks are:
- Low temperatures, which slow the cure and give moisture more time to react with the surface
- High humidity, which can be a concern in basements and garages
- Condensation, when the floor is near the dew point, the temperature where moisture beads up on surfaces
That’s why careful installers check air temperature, floor temperature, and humidity before they mix anything. Winter jobs may need heat. Most coatings also have a minimum cure temperature.
What to Do About Amine Blush
Amine blush washes off with water. Solvents don’t work well on it. Contractors typically scrub with warm, soapy water or a degreaser, rinse thoroughly, and let the floor dry before recoating.
Amine Blush FAQ
What is the cause of amine blush?
Amine blush forms when the curing agent in epoxy reacts with moisture and carbon dioxide in the air. Cold temperatures, high humidity, and condensation on the floor make it much more likely. Keeping the space warm and dry during the cure helps prevent it.
How do you get rid of amine blush?
Wash it off with warm water and soap or a degreaser, using a scrub pad or stiff brush. Rinse well and let the surface dry completely before the next coat. Solvents and sanding aren’t effective and can spread the film.
What does amine blush look like?
It can look like a cloudy, milky, or greasy haze on the epoxy. It may feel waxy or sticky, and sometimes shows up as white spots or crystal-like deposits. On darker colors it’s easier to spot as a dull patch.
Is amine blush a problem on a finished floor?
On a top coat that won’t be recoated, blush is mostly cosmetic and can cause dullness or yellowing. The bigger risk is between coats, where it can keep layers from bonding. That’s why it has to be removed before recoating.