How Does Pour Thickness Affect Colour Stability in Resin?

Heat Build-Up in Deep Pours

Thicker layers of resin tend to build up more heat as they cure, particularly because the exothermic (heat-producing) reaction intensifies when more product is used at once. This higher temperature can sometimes alter the resin’s colour or clarity, leading to unwanted yellowing or cloudiness over time. Choosing a formula like Epoxytable 10-Ten Deep Pour Resin, which is engineered for minimal heat generation even in pours up to 10cm, helps reduce this risk.

Choosing the Right Resin for Pour Thickness

It’s essential to select a resin product matched to your pour’s depth. Traditional surface resins are great for coats up to 1–1.5cm, such as Icrystal Clear Epoxy Resin. For larger projects or casting tables, opt for a deep-pour resin specifically designed for thicknesses of several centimetres. These products usually contain additives and have a slower curing time to control heat generation, offering improved colour stability and a more reliable clear finish.

Practical Tips for Achieving Colour Stability

• Pour in layers if your project exceeds the recommended depth per application to avoid excess heat.
• Work in a well-ventilated environment at a steady room temperature to moderate curing speed.
• Use products with built-in UV filters—these help slow the effects of light exposure, which also contributes to colour changes over time.
• Mix slowly and thoroughly to minimise microbubbles, which can scatter light and alter appearance in thick resin pieces.