How about getting resin, one which can withstand some heat and cover up the mesh. Sort of like fiberglassing, you have your form, then you cover the form with fiberglass and then add resin.?
I know fiberglass is very light, but can it resist heat?
I myself have thought about adding aluminum underneath..mainly for a nice clean look.
I've used a few cans of spray paint, but anything else I apply is going to be with a brush. Anything that repels water will do. Fiberglass might be a little thick as I only need to fill in the tiny holes in the screen. I'm guessing the heat from the screen would create a barrier against the cold air and keeping the entire car warm for longer as the wind is not cooling the underside when parked,as much as without the screen.
I've finished covering the entire underside of my car with window screen. This is touching the exhaust components in several places and has not burned nor melted. I plan now to paint the screen in some places to reduce friction more,leaving other parts near the exhaust unpainted for exhaust cooling. I know I'll have to cut a small hole when I change the oil ( filter is reachable from the top if I remove an electrical component from the fire wall and replace). Just drove 20miles from a cold start and managed 40mpg on 45/55mph zones.
I was thinking that you might be full of beans with your window screen idea...but it might be a really effective material to use. Why?
* fire proof
* should smooth airflow UNDER it...but also allow some of the air to escape DOWN that flows over the engine/trans...but forces it to "seep" thru...not forming local eddies?
* relatively inexpensive to use...light weight
* not so sure duct tape will hold it very long though...maybe sheetmetal screws and the plastic washers that are used with the nails to hold felt roofing material down?
Leading the perpetually ignorant and uninformed into the light of scientific knowledge. Did I really say that?
a new policy....I intend to ignore the nescient...a waste of time and energy.
The duck tape had started detaching from the screen in places but held well to the metal pinch weld along the sides. I've been adding more tie wraps to replace where the tape was holding the screen on. Still the tape keeps the tie wraps from tearing through the screen. No heat damage to the screen. The water temperature goes between 195 to 206 degrees, so I've been holding off on adding more paint.
After a summer spent playing with a coroplast-and-duct tape air dam, I'm not using any more duct tape on aero mods. Either it comes off when you don't want it to, or it leaves a mess when you pull it off deliberately.
I still use it in semi-protected locations and it does make sense for protection under zip-ties since there, sticking doesn't matter.
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.
Try gaffers tape. sure it's $8-15 a roll (depends on where you get it) but it lasts a long time and doesn't leave residue. 10x better than duct tape. Get it at theatre supply stores
EDIT: don't reccomend for use in permanent installation, still use fasteners for that.
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"