This upgrade is something I have wanted for awhile now. I cleverly devised many practical and impractical ways to keep them in place. In the end I just pushed them into the opening and they seem to stick. I did get some industrial Velcro in case they decide to stop sticking. 

A 3way fold makes them 18 inches long. The layers are held together with double backed carpet tape and the hinges are tape as well. 

Folded they make for easier storage. The material is from Lowes, Mylar on both sides and the middle is like bubble wrap. Supposedly rated R3, so R6 for my double layers. The reflective surface will be doing the bulk of the work in this climate. This project will run about $30 with lots of material left over. 

Multipurpose for microcruising, keeping the interior cooler and privacy ( this boat attracts a lot of interest at docks). I made tiny doors to peek out of without moving the whole thing. 

I haven’t done the front and rear windows yet, more difficult curves but I will get them done before launching. 

Caution!!! This material is impossible to work with in the sun without welders goggles!