Why epoxy turns yellow, and how to keep an epoxy table clear
Crystal-clear resin is a big part of an epoxy table’s appeal, so yellowing is a common worry. Nearly all epoxies can amber over time; how fast depends mostly on light, heat and the formulation. Here’s why it happens and how to slow it down.
- Epoxy resins contain aromatic groups that absorb UV light, which drives yellowing.
- Heat also causes yellowing; stabilizers and antioxidants slow both processes.
- Keep epoxy furniture out of long periods of direct sun, and use a UV-protective topcoat for outdoor pieces.
The chemistry, briefly
An article in PCI Magazine: Methods to improve resistance of BPA/BPF epoxy resins to light and heat damage explains that common bisphenol A and bisphenol F epoxy resins “typically contain aromatic groups with strong absorption in the UV range,” which makes epoxy vulnerable to UV degradation and limits its use outdoors. Light stabilizers slow effects “such as yellowing” by screening UV and slowing the radical reactions that degrade the resin, while antioxidants “further reduce the yellowing caused by heat.”
The article describes two main stabilizer types: UV absorbers, which absorb UV energy and convert it to harmless heat, and hindered amine light stabilizers (HALS), which trap the radicals that form. Many tabletop resins include stabilizers like these. The Industrial Clear epoxy FAQ, for example, says its resin contains UV-resistant additives that “slow down” the sun’s damaging effects. Slowing is the key word: no epoxy is completely immune.
Direct sun is the biggest factor
MAS Epoxies is candid in its MAS Epoxies: Table Top Pro FAQ: its tabletop epoxy “is not UV stable,” and “epoxy resin tends to yellow and may chalk when exposed to direct sunlight for extended periods of time.” For outdoor projects, it recommends protecting epoxy with a UV-protective varnish or paint. It also notes that pigmented epoxy may be somewhat more UV resistant than clear epoxy.
Heat during the pour matters too
Yellowing isn’t only a long-term issue. MAS warns that epoxy mixed or poured too warm can set too fast and get too hot, which “could cause it to yellow, distort or crack.” Thick river-table pours use deep-pour resins designed to release heat slowly (see best deep pour epoxy for river tables).
How to keep your table clear
- Place it away from strong direct sun, or use sheer curtains or UV-filtering window film.
- Keep it away from heat sources like radiators and fireplaces, and use trivets (see epoxy table heat resistance).
- Clean gently with mild soap; avoid harsh solvents (see epoxy table care).
- Consider colored or tinted resin, which tends to hide slight color shifts better than water-clear resin.
- Outdoor pieces need a UV topcoat, maintained over time.
Choosing the wood matters as well; darker woods like walnut make a slight warm tone in the resin less noticeable (see best wood for an epoxy river table).