How to avoid ripples

Ripples are a wavy, uneven texture across a pour that should have levelled out flat. They're a different problem from bubbles (trapped air) or cloudiness (moisture or under-mixing) — ripples happen when something disturbs the resin's surface while it's still curing, and the disturbance sets into the finish before it can level back out.

What causes ripples

• Temperature swings during cure. A drop in room temperature partway through the cure — from an open window, an air conditioner cycling on, or curing in an unheated space overnight — can cause the surface to skin unevenly.
• A mould or substrate that's a different temperature than the resin. Pouring warm mixed resin onto a cold surface can make it stop flowing and levelling properly right where it lands.
• Over-torching. Holding a heat gun or torch too close, or lingering in one spot, can distort the surface instead of just popping bubbles.
• Moving or bumping the piece too early. Resin needs to sit undisturbed while it self-levels; nudging the mould, the table, or the piece itself during this window can leave a ripple where the surface was already starting to set.
• Drafts and airflow across the surface. A fan, an air vent, or a doorway breeze can disturb the resin before it skins over.

How to prevent them

Keep the cure area at a stable temperature for the full cure — not just while pouring. Avoid working in a room where the temperature is likely to drop significantly overnight, and don't position your piece near a vent, window, or fan.

If your mould or substrate has been sitting somewhere cool, bring it up to roughly the same temperature as your workspace before you pour. A cold mould pulling heat out of the resin as it touches down is a common, easily missed cause of ripples right at the edges of a piece.

When torching to clear bubbles, keep the flame or heat gun moving in a sweeping motion rather than holding it in place, and work at a distance rather than close to the surface. Deep Pour resin should never be torched at all — the heat can cause cracking or yellowing in a deep, exothermic pour. Torching is for thin coating layers only.

Once poured, leave the piece completely alone until it has hard-cured. Cover it loosely to keep dust and drafts off the surface without letting the cover touch the resin.

Step-by-step

1. Stabilise the room before you pour. Confirm the space will hold a steady temperature for the whole cure, not just the moment you're pouring.
2. Warm up cold moulds and substrates. Let them reach roughly the same temperature as your resin before you pour onto them.
3. Torch lightly, if at all. Sweep the heat rather than holding it still, keep your distance, and skip torching altogether on Deep Pour.
4. Don't touch or move it. Let the piece sit undisturbed on a level surface until it's hard to the touch.
5. Shield it from drafts and dust. A loose cover that doesn't contact the surface protects the cure without introducing a new disturbance.

If ripples already appear

Once resin has gelled with a ripple in it, that texture is part of the cured surface — it generally can't be smoothed out without sanding back and recoating. If it happens, treat it the same as any other surface flaw: sand the affected area and pour a fresh, thin finishing coat once you've addressed whatever caused the disturbance in the first place.

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