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 the size of your casting area,
not just the product's maximum rating.
The headline number
Deep Pour is rated for a maximum layer thickness of 5 cm (50 mm) in a single pour — but that ceiling only
applies to small casting areas. Larger volumes generate more heat as they cure, and too much trapped heat can
cause cracking, discolouration, or warping.
Recommended pour depth by casting size
| Casting size | Safe depth per pour |
|---|---|
| Small (up to 10×10 cm) | Up to 5 cm (50 mm) |
| Medium (up to 25×25 cm) | 3–4 cm (30–40 mm) |
| Large (over 25×25 cm) | 2–3 cm (20–30 mm), poured in layers |
Why casting size changes the safe depth
Epoxy resin cures through an exothermic reaction — it generates its own heat as it sets. A large volume 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 casting 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, ideally 21–25°C (70–77°F). Cooler conditions slow the cure and reduce heat buildup — useful for thick pours.
- Monitor resin temperature with an infrared thermometer during cure if you're working at the upper end of the size/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.
Working time and cure
Deep Pour gives you approximately 1 hour of working time at 20–25°C (68–77°F) before it starts to set — plenty of
time to mix, pour, and adjust. The surface reaches a hard, dry-to-the-touch cure in 24 hours, but that's not
the same as fully cured — Deep Pour needs 48 hours to complete its full cure. Wait for full cure (48 hours)
before demoulding or heavy handling of large pours, not just the 24-hour hard-cure stage.
Related articles
- Mixing Ratio — How to Measure Resin and Hardener Correctly
- Bubbles — Why They Appear and How to Remove Them
- Arts & Crafts vs Deep Pour vs Table Top — Which to Choose?
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