How to Use a Torch on Resin: Bubble Removal Guide 2026

Why Resin Gets Bubbles

Understanding bubble formation helps you prevent and eliminate them effectively.

Sources of Bubbles in Resin

Bubbles in resin come from multiple sources. Mixing: stirring resin and hardener incorporates air—the most common bubble source. Pouring: resin falling from height into molds traps air. Porous substrates: wood, canvas, and other porous materials release air into resin during cure. Inclusions: flowers, paper, and other porous inclusions release air. Temperature: cold resin has higher viscosity—bubbles rise more slowly and may not reach the surface before cure. Colorants: some pigments and inks introduce air when mixed. Understanding your bubble sources helps you address them at the root—and use the torch effectively for what remains.

How the Torch Eliminates Bubbles

The torch works through two mechanisms. Heat reduces viscosity: warming the resin surface temporarily reduces its thickness, allowing bubbles to rise to the surface faster. Heat pops surface bubbles: the flame's heat causes the thin resin film over surface bubbles to expand and burst—popping the bubble and allowing the resin to flow back and fill the void. The torch is most effective on surface bubbles and bubbles near the surface. Deep bubbles (more than 5mm below the surface) are not reached by torch heat—they must be prevented through proper mixing and pouring technique.

Choosing the Right Torch

The right torch makes a significant difference in results and safety.

Butane Torch (Recommended)

A small butane kitchen torch (crème brûlée torch) is the standard tool for resin bubble removal. Key features to look for: adjustable flame (allows control of heat intensity), trigger lock (for continuous use without holding trigger), and refillable butane tank. Cost: ₹500-1,500 for a quality butane torch. Butane torches produce a clean, hot flame that's ideal for resin work. The flame temperature (around 1,300°C) is more than sufficient for bubble removal—the key is controlling distance and duration, not flame temperature.

Propane Torch (For Large Surfaces)

Larger propane torches are used for large resin surfaces (river tables, large canvases) where a small butane torch would take too long to cover the area. Propane torches produce a larger, hotter flame—require more careful distance control to avoid scorching. For beginners: start with a small butane torch and progress to propane only when working on large surfaces regularly.

Heat Gun (Alternative)

A heat gun (used for paint stripping) can substitute for a torch for bubble removal. Advantages: no open flame (safer for beginners), wider heat distribution. Disadvantages: less precise, can blow resin surface and create ripples if held too close, less effective on stubborn bubbles. Heat gun distance: minimum 15-20cm from resin surface. For beginners uncomfortable with open flame: a heat gun is a safer starting point before progressing to torch.

What NOT to Use

Never use: cigarette lighters (too small, inconsistent flame, difficult to control), candles (soot contamination), alcohol lamps (fire risk with resin fumes), or hair dryers (too much airflow, blows resin surface). These alternatives are either ineffective or create additional problems. Invest in a proper butane torch—it's the most important tool in your resin kit after the resin itself.

The Correct Torch Technique

Mastering torch technique is the difference between professional and amateur results.

The Golden Rules of Torch Technique

Five rules that prevent all common torch mistakes. Rule 1: Keep moving—never hold the torch in one spot. Rule 2: Maintain distance—minimum 10cm from resin surface for butane torch. Rule 3: Quick passes—each pass over any area should take 2-3 seconds maximum. Rule 4: Torch immediately after pouring—don't wait for bubbles to multiply. Rule 5: Multiple light passes beat one heavy pass—return for additional passes rather than prolonged single passes. These rules prevent the most common torch mistakes: scorching, yellowing, and surface distortion.

Distance: The Most Critical Variable

Torch distance from the resin surface is the most critical variable in torch technique. Too close (under 8cm): scorches resin surface, causes yellowing, creates surface distortion, and can ignite resin fumes. Too far (over 20cm): insufficient heat to pop bubbles effectively. Correct distance: 10-15cm for butane torch, 15-20cm for propane torch. Test your distance on a small test pour before working on important pieces. The correct distance produces a visible "shimmer" on the resin surface as heat reduces viscosity—without any smoke, discoloration, or surface distortion.

Motion: Sweeping, Not Hovering

Torch motion should be a continuous sweeping movement—like painting with the flame. Correct motion: sweep the torch in smooth, overlapping passes across the resin surface. Move at a consistent speed (approximately 15-20cm per second). Overlap each pass by 30-40% to ensure even coverage. Never hover the torch over one spot—concentrated heat causes scorching. For round coasters: sweep in circular motion following the coaster shape. For rectangular pieces: sweep in parallel lines from one edge to the other. For large surfaces: work in sections, completing each section before moving to the next.

Timing: When to Torch

Timing of torch passes is as important as technique. First pass: immediately after pouring—within 2-3 minutes. This first pass pops the majority of surface bubbles before they multiply. Second pass: 10-15 minutes after pouring—catches bubbles that have risen from deeper in the resin. Third pass: 30-45 minutes after pouring—catches late-rising bubbles. For ONE Resin with 120-minute pot life: you can continue monitoring and torching for up to 60-90 minutes after pouring. After this point, resin viscosity increases significantly and bubbles no longer rise effectively. For 12H Resin with 40-minute pot life: complete all torch passes within 30 minutes of pouring.

Reading the Resin Surface

Learn to read the resin surface to know when torching is effective. Signs torching is working: bubbles visibly pop as torch passes over, resin surface shows slight shimmer from heat, surface appears smoother after each pass. Signs you're torching too aggressively: smoke rising from resin surface (stop immediately), surface appears to ripple or distort, resin color changes (yellowing). Signs torching is no longer effective: resin surface has gelled (no longer liquid)—stop torching at this point, as heat on gelled resin causes surface damage without popping bubbles.

Torch Technique for Different Applications

Adapting technique for specific resin art applications.

Coasters

For round coasters: hold torch 12cm above surface, sweep in circular motion following the coaster shape. Complete one full circular sweep per pass. Repeat 3-4 times immediately after pouring, then check every 15 minutes for the first hour. ONE Resin's superior self-degassing means most bubbles pop naturally—torch assistance is minimal. Total torch time per coaster: 30-60 seconds across all passes. Don't over-torch coasters—excessive heat on small pieces can cause warping.

Jewelry Molds

Jewelry requires the most delicate torch technique—small pieces heat up quickly and can be damaged by excessive heat. Distance: 12-15cm minimum. Duration: 1-2 seconds per pass maximum. Motion: quick sweep across all mold cavities in one continuous motion. For 12H Resin jewelry: one or two light passes immediately after pouring is usually sufficient. 12H Resin's excellent self-leveling and self-degassing minimizes bubble formation in small jewelry molds. Over-torching jewelry molds can cause resin to flow out of shallow molds—be especially careful with very shallow molds.

Large Canvases and Wall Art

Large surfaces require systematic coverage to ensure all areas are torched. Divide the surface into sections (30x30cm each). Work through sections systematically—left to right, top to bottom. Complete all sections in one pass, then repeat. For large surfaces: a propane torch or heat gun covers area more efficiently than a small butane torch. ONE Resin's 120-minute pot life gives ample time to torch large surfaces thoroughly without rushing.

River Tables

River table resin channels require thorough torching due to the large volume and depth of resin. Torch the river channel immediately after each batch pour. For deep rivers poured in layers: torch each layer before adding the next. The river channel edges (where resin meets wood) are particularly prone to bubbles—pay extra attention to these areas. Use a propane torch for river table work—the larger flame covers the channel width more efficiently. Torch every 15-20 minutes during the first hour of cure as new bubbles continue to rise from the deep pour.

Torch Safety

Essential safety practices for torch use in resin work.

Ventilation

Always work in well-ventilated space when using a torch on resin. The torch flame can ignite resin fumes if ventilation is poor and fume concentration is high. Open windows and doors, use a fan to move air, and avoid working in enclosed spaces. In India's hot climate: working outdoors or in a well-ventilated covered space is ideal for torch work. Never use a torch in a room with strong resin fumes—ventilate first, then torch.

Fire Safety

Keep flammable materials away from the torch work area. Isopropyl alcohol (used for cleanup and effects) is highly flammable—ensure it's capped and stored away before using torch. Paper towels, packaging materials, and other flammables should be cleared from the work area. Keep a small fire extinguisher or bucket of water nearby when doing extensive torch work. Never leave a lit torch unattended. Turn off torch immediately after use—don't set it down while lit.

Personal Protection

Wear safety glasses when torching—resin can splatter when bubbles pop aggressively. Nitrile gloves protect hands from resin contact. Keep hair tied back and away from the flame. Avoid synthetic clothing that can melt if accidentally contacted by flame. These precautions are simple and become automatic with practice—don't skip them, especially as a beginner.

Troubleshooting Torch Problems

Solutions for the most common torch-related issues.

Bubbles Keep Coming Back

If bubbles reappear after torching, they're rising from deeper in the resin—not a torch technique problem. Solution: torch in multiple passes over the first hour of cure rather than one intensive pass. Bubbles from deep in the resin take time to rise to the surface. For ONE Resin: check every 15-20 minutes and torch as needed for the first 60-90 minutes. After this point, increasing viscosity prevents new bubbles from rising—remaining deep bubbles are trapped and cannot be removed.

Resin Yellowing After Torching

Yellowing after torching indicates excessive heat—torch held too close or too long in one area. Prevention: maintain minimum 10cm distance, keep torch moving, limit each pass to 2-3 seconds per area. If yellowing has occurred: it cannot be reversed in the affected area. For future pours: increase distance and reduce pass duration. Note: yellowing from torching is different from yellowing from UV exposure or incorrect ratio—it appears immediately after torching rather than developing over time.

Surface Ripples or Distortion

Surface ripples after torching are caused by torch held too close or airflow from the torch disturbing the liquid resin surface. Prevention: maintain correct distance (10-15cm), use smooth sweeping motion, and avoid directing torch airflow at a steep angle to the surface. For large surfaces: hold torch at a slight angle (30-45 degrees) rather than perpendicular—this reduces airflow impact on the resin surface while maintaining effective heat delivery.

Torch Not Popping Bubbles

If torch passes aren't popping bubbles, possible causes: torch held too far away (increase heat by reducing distance slightly), resin has already gelled (torching is no longer effective—stop), or bubbles are too deep to be reached by surface heat (prevention required, not torch). For 12H Resin: the 40-minute pot life means the effective torching window is shorter—complete all torch passes within 25-30 minutes of pouring.

Frequently Asked Questions

Q: How long should I torch resin?

Total torch time per piece: 30-90 seconds of actual flame contact, spread across multiple passes over 60-90 minutes. Each individual pass over any area: 2-3 seconds maximum. The key is multiple light passes over time rather than one prolonged pass. For ONE Resin: torch immediately after pouring, then at 15-minute intervals for the first hour. For 12H Resin: torch immediately after pouring and once more at 15-20 minutes—the shorter pot life limits the effective torching window.

Q: Can I use a lighter instead of a torch?

A lighter is not recommended for resin bubble removal. Lighters produce an inconsistent, small flame that's difficult to control at the correct distance. The flame is too small to cover resin surfaces efficiently. Lighter fuel can also contaminate resin if held too close. A butane torch (₹500-1,500) is a worthwhile investment—it's the correct tool for the job and produces consistently better results. If you're just starting out and don't have a torch yet: use a toothpick to manually pop surface bubbles as a temporary measure while you acquire a proper torch.

Q: Why does my resin smoke when I torch it?

Smoking resin indicates the torch is too close or held in one spot too long—the resin surface is being scorched. Move the torch immediately and increase distance. Scorched resin cannot be repaired—it will cure with a yellowed or browned area. Prevention: maintain minimum 10cm distance and keep torch moving continuously. If you see any smoke: immediately increase distance and reduce pass duration. Properly torched resin should show a slight shimmer from heat—not smoke.

Q: Should I torch before or after adding inclusions?

Torch the base resin layer before adding inclusions (flowers, glitter, foil). After adding inclusions: use a toothpick to pop bubbles around inclusions rather than torch—torch heat can displace lightweight inclusions and cause them to move or sink. For pressed flowers: place flowers on gel-stage base layer (no torching needed at this stage). For glitter and mica powder: these are added to liquid resin and can be lightly torched—the heat enhances shimmer effects. For foil flakes: place with tweezers after torching the base layer.

Q: How do I remove bubbles from deep in the resin?

Deep bubbles (more than 5mm below the surface) cannot be removed by torch after pouring—they must be prevented. Prevention strategies: mix resin slowly to minimize air incorporation, warm resin slightly before mixing in cold conditions (reduces viscosity, helps bubbles rise faster), seal porous substrates and inclusions before embedding, pour resin slowly from low height to minimize air trapping, and use ONE Resin's superior self-degassing formulation. If deep bubbles are a persistent problem: consider vacuum degassing (professional technique using vacuum chamber to remove all bubbles before pouring).

Q: Can I torch resin multiple times during cure?

Yes—multiple torch passes during the first hour of cure is the correct technique. Torch immediately after pouring, then at 15-20 minute intervals as new bubbles rise from deeper in the resin. Stop torching when resin reaches gel stage (surface is no longer liquid)—torching gelled resin causes surface damage without popping bubbles. For ONE Resin: effective torching window is approximately 60-90 minutes after pouring. After this point, cover with dust shield and allow to cure undisturbed.

Conclusion: Master the Torch, Master Resin Art

The torch is a simple tool with a profound impact on resin art quality. Correct technique—right distance, continuous motion, proper timing, and multiple light passes—produces bubble-free surfaces that showcase the beauty of ONE Resin and 12H Resin at their best. Incorrect technique—too close, too long, too late—creates problems that can't be fixed after cure.

Practice torch technique on test pours before working on important pieces. Within a few sessions, correct torch technique becomes instinctive—and bubble-free resin becomes your consistent standard. Order from Magnifico Resins and create resin art with the confidence that comes from mastering every tool and technique.