Does anyone know whether acrylic is totally impervious to water please?
I believe it is....
Reason for the question is that caravans use two panels sealed together as a form of double glazing, not fully sealed, they have a pair of removable bungs. The problem is that under certain contains moisture trapped between the panels can condense out on the inner or outer pane causing misting. One suggestion is to remove the bungs on a warm dry day, then re-seal after venting. Another suggestion is that any moisture can migrate through the acrylic panel anyway, so removing the bungs is a waste of effort.