Why did my resin cure with bubbles?
Common Causes of Bubbles
Bubbles are the most common issue in resin crafting. They occur when air gets trapped in the resin and can't escape before curing. Mixing vigorously, pouring from a height, or using cold resin can all introduce bubbles.
Resin that is too thick (cold) holds bubbles more easily. UV resin can also bubble if applied too thickly or if the surface is uneven. The key is to minimize air introduction and help bubbles rise before curing.
- Stirring too fast or whipping air into the resin.
- Pouring from too high, which creates air pockets.
- Using cold resin—warm it slightly to reduce viscosity.
- Working in a cold room; ideal temperature is 70-75°F (21-24°C).
- Not allowing enough time for bubbles to rise before curing.
How to Prevent and Remove Bubbles
Mix slowly and deliberately, scraping the sides and bottom of your cup. Let the mixed resin sit for a few minutes so bubbles can rise to the surface. You can also use a heat gun or torch quickly passed over the surface to pop bubbles.
For UV resin, work in thin layers and use a toothpick to remove bubbles before curing. A vacuum chamber or pressure pot can eliminate bubbles for advanced users, but simple techniques work well for most projects.
Fixing Bubbles After Cure
If bubbles are already cured, you can often sand them out and apply a fresh topcoat. For surface bubbles, sanding with fine grit and polishing can restore clarity. Deep bubbles may require drilling and filling, but that's usually not necessary for small ones.
Common mistakes
- Mixing quickly to save time, which introduces more air into the resin.
- Using a torch too close or for too long, which can burn the resin or create new bubbles.
- Pouring resin in a cold room without warming it first, making bubbles harder to release.
