reflextics - well the shiny bubble wrap type stuff

[sternwake]

Look into Nashua flexfix tape.

it is shiny and very sticky and can be stretched slightly. The peel off backing aluminum tape will not like being bent rolled and folded and tears way too easily.

When making window shades, know that when folded and rolled up many times, they will get shorter over time and extensions will be required to fill in the gaps at the edges.

I use magnets, but not attached to the reflectix but simply to keep the shades from succumbing to gravity, The magnets stay on the window frames when I pull the shades.

Part of the reason reflectix is good for this duty is the reflective factor, but the other portion is emissivity. A hot shiny surface does not radiate much heat compared to a hot black surface. So if one has reflectix painted black on one side facing out, but shiny on the inside, the inside reflective portion will not radiate as much heat inward compared to if the interior face was black.

But the black facing outward will also heat up much more.

Also keep in mind that a saggy reflectix window shade several inches from the window will superheat the air between the window and shade and this will make it inside the vehicle. So tight fitting shades are more effective than those with big gaps between glass and shade.

Over time, the window shades will sag in the middle. I used the nashuaflexfix tape to adhere very stiff cardboard in strips so that it cannot crease in the middle and can still be easily rolled or folded. I have used thin white oak strips along the edges as well.

My shades are pretty beat up and are likely 10 years old. I could go nuts with another layer of flexfix tape, but it would be more wise to get a new roll of reflectix and make new ones, or just add another layer to the existing ones and accept their extra bulk when rolled up/folded.

As far as making them tight fitting, one ca unroll the reflextix over the outside of the window, and trace it with a sharpie, and then cut it a bit outside that line, large, as one can always shave it down, but do keep in mind they will get shorter when folded or rolled often.

My conversion van windows are smoked glass, in direct sun they get very hot and radiate a lot of heat to the interior. I have some thick cardboard 3 or 4 piece kind of interlocking panels to fit tightly within the windows, with black contact paper facng outward with curtain materials facing inward,. The black contact paper faded to purple pretty quickly so I painted it black with high temp flat black gas grill paint. This significantly lowers the amount of heat that radiates inward but I still have some dollar store reflectix that I will put on the interior, as the silver surface will not radiate much of that heat to the interior.

I can remove the panels pretty easily when i want to look out.

I also have some black bungee cords that have multiple attachment points around the windows, When it gets super hot I will use the bungees to hold my pillows or extra blankets to the sunny side window, and my passenger side rear window has basically been covered by my sleeping bag for months as it usually faces east and I am a bit of a late sleeper.

I like usng some Isoproply alcohol to wipe down the reflextix before adhering the Nasua Flexfix tape to promote strong adhesion.