Help! Simple but difficult way to semi stick reflective mylar to sheet metal
Well, anyway, we're in the process of finalizing a design for a solar hot water heater and are still trying to figure out a good/better way to stick our mylar to our sheet metal. The sheet is about 10 ft. (sorry about that old fashioned non-metic system usage, but we're on the U.S.-Mexican border and most of the things here in Mexico are still measured in the old system - sigh) by about 4 ft.
We have used axle grease - it's o.k. but hard to spread and to make into a VERY thin film. If the film is not thin bulges appear in the mylar since itself is only about 2 mil thick. It was good, on the other hand, because it allowed us to position the film correctly on the metal sheet...
So, this time we tried silicone - out of a spray can. It also seems to be good, perhaps a little better since we can spread it with a small paint roller but after several days it's not holding the mylar down well enought (which is probably to be expected since we're using silicone and it's not really sticky).
So, we need something which will allow us to position the film (slippery) while being a very, tiny, wee, itsy bitsy sticky in the long run. It cannot of course be anything biodegradable - like honey - yuck - for obvious reasons (it's going to be in the sun and eventually it will, biodegrade, into who knows what).
Maybe silicone and ... Elmer's glue??? We're stuck. And, after googleing till our eyes have dropped out, we can't find any reflective mylar with a sticky backing. What the heck do they stick on those window tinting sheets???
Anyway, any help would be greatly appreciated and of course, Have a wonderful afternoon! :)