How to use a torch to get rid of bubbles

A torch is one of the quickest ways to clear bubbles from a resin surface while it's still workable. The heat briefly thins the top layer of resin, which lets trapped air rise and pop before the surface sets. This guide covers when torching is appropriate, how to do it safely, and how to fix a project you've over-torched.

When a torch is the right tool

Torching works on thin, open pours — coating layers on Arts & Crafts and Table Top projects, canvas art, coasters, and similar surface pours where the bubbles are near the top and the resin is still liquid enough to move.

Do not torch Deep Pour projects. Deep Pour cures exothermically and is already generating its own heat as it sets; adding a torch or heat gun on top of that raises the risk of cracking and yellowing. If you're working on a Deep Pour, use a cocktail stick or an isopropyl alcohol spritz for surface bubbles instead, and see our Deep Pour article for how that product is layered and cooled.

A torch is also not a substitute for good mixing and pouring technique. It removes bubbles that already formed — it doesn't fix a pour that trapped a lot of air to begin with. If you're getting heavy bubbling on every project, it's worth checking your mixing speed, pour thickness, and workspace temperature first.

How to torch safely

1. Work while the resin is still fluid. Torching only helps during the working time window for your product — once the surface has started to gel, heat won't pop bubbles and can instead distort the surface. If you're not sure how long you have, check the working time for your specific product in our Mixing Ratio article.
2. Start further away than feels necessary. Hold the torch a reasonable distance above the surface and switch it on before bringing it toward the piece, rather than igniting it close to the resin.
3. Sweep, don't hover. Move the flame steadily across the surface in passes. Holding it still over one spot is what causes scorching, localised yellowing, or a pitted, "cratered" texture — the goal is a quick pass that pops bubbles, not sustained heat.
4. Make a second pass if needed. Some bubbles surface a little later as the resin keeps settling. Check back over the piece and repeat a light pass if new bubbles appear, staying within the same working-time window.
5. Cover the piece once you're done. Dust and hair are much more likely to land on a piece while it's still tacky from torching, so cover it while it finishes curing and remove any debris with tweezers before the surface sets fully.

Avoiding the common mistakes

• Holding the flame too close or too long is the main cause of scorching and surface distortion. Keep the torch moving.
• Torching after the surface has gelled does more harm than good — it can wrinkle or drag the surface instead of clearing bubbles.
• Combining a torch with an alcohol spritz is a fire risk. Isopropyl alcohol is flammable — use one method or the other on a given pass, never both at once, and let any alcohol fully evaporate before bringing a flame near the piece.

If you've over-torched a project

If a section has scorched, pitted, or gone uneven, don't try to fix it with the torch — let the piece cure fully first. Once it's hard, sand down the affected area with a fine sandpaper (80–120 grit works well) to level out the bumps, then wipe away the dust with a damp cloth. A fresh, correctly measured coat poured over the sanded area will self-level and cure clear, covering the sanding marks.

Related articles

• Bubbles — Why They Appear and How to Remove Them
• Mixing Ratio — How to Measure Resin and Hardener Correctly
• Deep Pour — Maximum Depth, Layering, and Cooling Time