How to Fix Bubbles in Cured Resin

Short answer: it depends where the bubble is. Surface bubbles and open pits can be fixed: sand the area smooth (or open the bubble with a small drill bit or needle), wipe off the dust, then fill the pit with a drop of fresh resin or pour a thin top coat over the whole piece. Bubbles trapped deep inside a clear piece can't be removed after curing; you can only hide them with an opaque or decorative top layer, or recast. Mix a small measured batch for the repair.

Step by step: surface bubbles

1. Wait for the full cure on the label so sanding doesn't gum up.
2. Pop or open each bubble so it is an open pit; sand the surface with progressively finer grits.
3. Remove all dust (a damp, lint-free cloth, then dry fully).
4. Fill pits with a drop of mixed resin, or pour a thin top coat; pass a heat gun or torch briefly over it to release new bubbles.
5. Let it cure fully before using or gifting.

How much resin for a top coat?

Area × thickness: use the coating calculator for flat pieces or the mold volume calculator; a thin coat on a small piece needs only a few ml. Split the batch with the weight converter.

Prevent them next time

Warm the bottles, mix slowly, pour thin layers, and use heat on the surface: see how to get bubbles out of resin while pouring and heat gun vs torch. For casting, some makers use a pressure pot (pressure pot vs vacuum chamber).

FAQ

Can you fix bubbles in resin after it cures?

Surface bubbles and pits, yes: open them, sand, clean and fill or top coat. Bubbles sealed deep inside can't be removed, only covered or recast.

Will a top coat hide bubbles?

A clear top coat fills and levels open pits on the surface. It won't remove bubbles inside the piece.

How do I fix bubbles in UV resin?

Open and fill the pit with a drop of UV resin and cure it under the lamp in a thin layer; small pieces are quick to redo.

More tools: resin calculator · mix ratio by weight · cure time · mold volume · tabletop coating · pouring too thick