TABLE OF CONTENTS
Mastering the Art of Bubble-Free Epoxy Resin
The Ideal Temperature for Bubble-Free Epoxy Resin
Workspace Temperature: Create in a space where the ambient temperature is room temperature, or between 72°-85°F. Ideally, try to be closer to 78°. At the right temperature, your resin remains free from a cloudy or milky appearance.
Warming the Resin: Cold resin has a taffy-like consistency and is more likely to trap microbubbles. Warm the bottles in a lukewarm water bath before mixing, but remember, warmer resin has a shorter working time.
Mixing and Pouring Techniques to Eliminate Microbubbles
Mixing Ratio: Always measure your epoxy resin as accurately as possible. Use a container that has clear markings of millileters or ounces which helps improve your accuracy. Don't just eyeball it. Many epoxy resins are developed as a 1:1 mixing ratio by volume, but always check with your supplier first.
Stirring Strategy: Stir smoothly and consistently, scraping the sides and bottom. Avoid whipping the mixture, which introduces unnecessary bubbles. Slow and steady. You can also try using metal stir sticks or different shapes which might help.
Pouring Practice: Gently pour the mixture from a close height. High pours introduce more air. Pouring too thick can trap bubbles; the recommended thickness for epoxy resins can range so it might be best to pour in layers.
Removing Microbubbles with a Heat Gun or Torch
Torching: Right after pouring, use a propane torch to quickly sweep across the surface and remove bubbles. Torches heat the resin's surface quickly, making it thinner and allowing bubbles to escape. Be sure to not overheat it, only a quick pass is necessary.
Heat Guns: These are better suited for silicone molds. Direct flames can damage the molds, whereas a heat gun provides gentler heat. They aren't always as effective as a torch, but still a great tool to have.
Isopropyl alcohol: You can spritz a small amount of isopropyl alcohol onto the surface to help release bubbles. It needs to be a fine mist and should only be a small spray. Warning: do not use a torch or heat gun immediately after isopropyl alcohol.
Seal Your Surface Before Applying Epoxy Resin
Some materials like wood and paper can release air when covered in resin. You can apply a very thin layer of epoxy resin to some surfaces to help prevent this, or using a spray sealer before applying the epoxy. Doing this will help prevent trapped air from turning into bubbles in the resin coating.
Addressing Bubbles in Epoxy Resin Post-Curing:
If you spot a bubble after the resin has cured, all hope isn't lost.
Sanding: Sand down the entire surface of your piece, focusing on the bubbled areas. Use coarse sandpaper (like 80 grit). Though the piece might look scratched post-sanding, a new layer of resin will make it clear again.
Wipe Down: Before pouring a fresh layer of resin, clean the sanded surface. Remove all dust and debris for a flawless finish.