I am building a box intended to insulate 3D printer filament from heat and humidity. I plan to heat this box a bit (haven't landed on exactly where yet but somewhere 40-80C) and run airflow through the heater in a roughly closed loop.

The box will be made from 3mm or 1/8" acrylic and joined with a 3D printed plastic frame (with a plastic that will not melt at these temperatures). There will be bolts going through the plastic frame and the acrylic to hold it moderately tight but there will still be cracks along each edge. Hard to tell how significant they will be from an insulation perspective.

I would love to give it a bit of "extra" insulation by putting some spray foam in the cracks and crevices of the frame. Hopefully to keep the more humid air from outside out and the hot air inside the box in the box as much as possible.

I realize there are things I could do for even better insulation like double wall, or thicker acrylic but this is sort of all I have to work with.

I know this is a little out of scope for home improvement but I found the advice on low expansion spray foam on here to be the most useful compared to what I can find elsewhere.

I am worried that even the low expansion spray foams would not be gentle enough on the thin acrylic, especially when you consider it may frequently go from room temperature to 60C. I am also worried that it could over-expand and break the frame or make it otherwise impossible to put together.

Do they make spray foams that expand to fit but then ultimately are easy to remove?

Is low expansion spray foam a good candidate here? I could also look into different types of foam gaskets.