How do I remove cloudy spots, water spots, or stains from cured epoxy?

Clean first. Cloudiness and water-spot-like marks on an older surface can be a film left by soap or glass cleaner, or light surface wear, especially outdoors. Wipe with a 1:1 mix of isopropyl alcohol and water on a clean microfiber towel. If light cloudiness remains, customers have had good results with a plastic-safe polish such as Novus 2. We have not tested it, so test a small, hidden spot at your own risk.

If cleaning doesn't remove the marks, such as hazy rain spots on an outdoor table or stains where a coffee pot or cutting board sat, sand and recoat:

1. Sand off the top layer until the blemishes are gone. Any grit to start; finish with 220-320 grit. 2. Wipe off all sanding dust with denatured alcohol or acetone. 3. Pour a new flood coat of UltraClear Bar & Table Top Epoxy directly over it. It fills the sanding scratches and cures clear and glass-like again if mixed correctly.

For a small stain, spot-fix instead: brush a thin layer of epoxy over the sanded area like a seal coat and smooth the brush strokes with a heat gun.

Going forward, keep a trivet or mat under coffee pots and cutting boards. On outdoor tables, a spray-can coat of UV polyurethane over the cured epoxy helps limit sun damage. Rings from hot items on epoxy that never fully cured are a different problem; see "How do you remove heat rings from epoxy?"