Entrapped air is usually caused by aggressive mixing of the resin or can be introduced when encapsulating objects. Porous objects, such as wood, and objects with curved surfaces, such as seashells, can trap air that can migrate into the resin once submerged. To minimize bubbles, use the following practices:
- Do not aggressively mix epoxy. Mix slowly until the epoxy is streak-free and clear.
- If including wood or other porous items, seal coat them before encapsulation. Any air present will be unable to escape.
- Objects with curved surfaces can be brushed with UVPoxy before adding them to the mold. This breaks the surface tension and can reduce bubbles.
- Pour slowly around encapsulated objects. Pouring too quickly can result in pockets of air trapped under objects which may migrate out during cure.
Monitor the resin for bubbles after pouring, checking periodically during the working time. If bubbles do appear in the epoxy, wait for them to come to the surface then use the following methods to release the air:
- Use a torch to heat and release bubbles. Hold the flame tip 1-2” off the surface and move the torch quickly in a sweeping motion to burst all visible bubbles. Do not allow the flame from the torch to touch the epoxy. A heat gun can also be used but care must be taken not to disturb the surface of the resin.
- Use a toothpick or other pointed tool to release the air bubble.