Thanks for the links.
Privacy is #1. Heat and cold blocking is #2, and light blocking last on the list.
An easy on/off is our goal, so we're going to install a bunch of neodymium magnets in the casing of homemade portlight covers.
I think we'll incorporate part of that video with these:
K&J Magnetics - Products
in six portlights we'll have approximately 200 of these puppies sewn into the edge of the fabric
By putting the magnets in the covers, this will allow the fabric to be crunched, rolled etc. and tossed into whatever area we choose (excepting of course, the fluxgate compass
The backside of the aluminum
portlight frames have convenient slots for the installation
of magnetic strip material which is available everywhere CHEAP!
I'll cut the continuous tape to the right width and stick it in place with the peel and stick.
It can't go anywhere even if the adhesive
fails, as it's held in place by the portlight frame screws.
Yeah, I know we need to get the N/S polarity right with the individual magnets. No sweat, we'll set up an assembly line!
What's not to like?
Thanks everyone for your suggestions.