Deep Pour resin is designed for thick, single-pour projects like river tables, deep moulds, and flower preservation blocks — but how deep you can safely pour in one go depends on how much resin you mix, not just the product's maximum rating.
The headline number
Deep Pour is rated for a maximum of 50 mm in a single pour. The safe depth falls as the batch gets bigger, because a larger mass of curing resin holds more heat — and too much trapped heat can cause cracking, discolouration, or warping.
Recommended pour depth by batch size
| Batch size | Maximum depth per pour | Room temperature |
|---|---|---|
| up to 5 kg | 50 mm | 22–25°C |
| 5–10 kg | 30–40 mm | 20–23°C |
| 10–20 kg | 20–30 mm | 18–21°C |
| over 20 kg | 20–30 mm | below 18°C |
Why batch size changes the safe depth
Epoxy resin cures through an exothermic reaction — it generates its own heat as it sets. A large mass of resin holds more heat than a thin, wide pour, and if that heat can't escape fast enough it can cause:
- Cracking as the resin cures unevenly through its depth
- Discolouration or yellowing from overheating
- Warping or bubbles that affect clarity and finish
Layering technique for large or deep projects
- Pour your first layer within the safe depth for your batch size.
- Allow it to cool and set partially — it should still be slightly tacky, not fully cured — before adding the next layer. This lets each layer bond to the one below without trapping a full new exotherm on top of an already-hot layer.
- Repeat until you reach your target depth.
Working conditions that help
- Temperature-controlled room, matched to your batch size (see the table above). Cooler conditions slow the cure and reduce heat build-up — useful for thick pours.
- Monitor resin temperature with an infrared thermometer during cure if you're working at the upper end of the depth table; reduce layer thickness if it's climbing fast.
- Good ventilation helps dissipate heat from the workspace.
- Use a mould designed for epoxy — silicone moulds handle heat dissipation better than some rigid plastics.
- Never use a heat gun or torch on Deep Pour — it adds heat to a reaction that is already generating its own.
Working time and cure
Deep Pour gives you around 1 hour of working time at 25°C before it starts to set — less with larger batches. It cures in 48–72 hours, depending on temperature and mass. Do not demould before 48 hours, and wait the full cure before heavy handling of large pours. Full mechanical strength develops over about 21 days.
Related articles
- Mixing Ratio — How to Measure Resin and Hardener Correctly
- Bubbles — Why They Appear and How to Remove Them
- Arts & Crafts vs Table Top vs Deep Pour vs UV — Which Resin Do I Need?
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