Acrylic Expansion Gap

[Justintime]

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

[JFeig]

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.

[Justintime]

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

[JFeig]

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

[Justintime]

Thanks that's really helpful.