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Yellowing caused by sunlight is the number one concern for deep pour resin projects like bespoke tables and river castings. This straightforward guide explains why discolouration happens, how to select truly UV-stable epoxy, and what steps you can take to preserve crystal clarity in your most ambitious pieces.
Why Does Yellowing Occur in Deep Pour Projects?
Exposure to sunlight—particularly its UV rays—can gradually change the chemical structure of epoxy, causing it to yellow. This effect is especially noticeable in thick, clear pours where pristine clarity is essential.
- Direct sunlight causes yellowing much faster than ambient light
- Even indirect light can dull or tint resin finishes over time
- All deep pour resins will eventually yellow if not properly protected
Choosing UV-Stable Resin: What to Look For
The single most important defence against yellowing is selecting an epoxy resin that’s formulated with robust UV filters. Not all resins are equal—those with strong UV resistance remain clear and vibrant for far longer, especially under UK daylight conditions.
- Look for products that specify strong UV resistance
- Recommended: Epoxytable 10-Ten for pours up to 10cm
- For projects up to 5cm, consider EpoxyTable 5-Five
Both feature robust UV filters to help minimise yellowing, making them a smart choice for sunlight-exposed work.
Practical Tips to Further Reduce Discolouration
Alongside choosing a UV-stable epoxy, you can slow down yellowing with some easy aftercare:
- Display finished pieces away from direct, prolonged sunlight
- Use curtains or blinds to shield from harsh midday rays
- Keep surfaces clean and dust-free, as dirt can worsen UV damage
- Apply a compatible topcoat with additional UV protection for highly exposed surfaces
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By selecting UV-resistant resins and taking simple preventative measures, your deep pour creations will remain beautifully clear for years. For more thick casting tips and advanced advice, explore our main epoxy resin for thick casting guide.
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