Harishwar,

A paint that can withstand abrasion by metal? That will be challenging at *any* temperature!

Perhaps an inner lining of copper or brass sheet (thin!) would prevent the chamber from being damaged?

This really depends on how you are using the chamber.

If you are simply placing cold items in it for observation or fairly gentle manipulation then a vinyl based paint (a scrubbable household paint of the type that are generally available in DIY shops) is more than adequate - but will need 2 to 3 coats. These vinyl paints bond well to polystyrene and are good down to very low temperatures.

If you are doing something more active, say mixing products or observing dynamic processes then you can get exterior vinyl paints that contain sand or particles (used for painting outside walls etc) and these are very resistant to abrasion, but it would be better to line the chamber with heavyweight aluminium foil, or lightweight aluminium plate to provide real resistance.

If metal is not appropriate then the self-adhesive films used to line kitchen drawers and cabinets are relatively cheap and resist hard wear.

However, please be aware that 50mm of polystyrene is really not adequate at -77C if you are maintaining these temperatures for extended periods. Losses (heat coming into the chamber ) can exceed 16 to 20 Watts per square metre of internal wall area. This can be devastating to a small cold part - much better if you look at 100 to 150mm

@ James Garry

A paint that can withstand abrasion by metal? That will be challenging at *any* temperature!

--- No it is just a chamber where there is no direct contact or hammering of metal parts. Only to protect from scratches if happens and temperature in constant at 77K.

Thanks

@ Ian Proffitt Yes sure I will try the same and consider the parameters to avoid any losses.

Thanks