The Framers Forum

Anyone know the recommended expansion gap within the rebate for a 1.1m x1.7m frame using 5mm cast acrylic? The frame rebate is 7mm

It depends on how much of a temperature change you are planning for.

The coefficient of thermal expansion for acrylic is approximately 0.075 mm per meter per degree Celsius (mm/m/K), which can vary slightly depending on the supplier.
This value indicates that a 1-meter acrylic panel will expand by about 1.5 mm when the temperature increases by 20°C.

Jerome, does that vary at all depending on the thickness of the acrylic?

COF works in all directions at the same time. The thickness is of little or no concern.

Thanks that's really helpful.