Ever sheet-metaled a solar collector box?
Solstar 1978-'80s had a neat layers- window-screen dust collectr (solar) that required great air-tight filtering for longevity. (done, easy enough).
We had in the early 80's those "oil-windfall credits of 50%" Solar wind Geo-T(122f water-GT, not shallow ground loop GT)...
In the solar hype: SheetMetal boxes from 10x4's were punched into production for 2 to 6 collector AIr-Water heating in homes and offices, very well enough 24ga galv with 1.1/2" iso-foam walls and 3 window screens and a layer of PTFE clear and sundex or other Fylon top glazing (UV protected-er).. lasted over 20 years on buildings and homes (boxes repainted at spots...).
CAN DO TODAY, I have reason to believe. Some day I will post the leaflet with my pic from 1980 holding a collectr- (looking-installer-like) in southern of a north state.
Window screen material can be found OEM baked at 500 for a charcol grey door/window screening solar collection.
GET CERTS... ? for the eStar credentialing that is not with self-made uncertified's, may be an issue if not produced in-expensively enough.
Can put out 3000+ btuh's normal/perpindicular to a zone 5 winter sunlighting ! and 8x4 sheets close enough that 2 heat 80 gal tanks daily and MORE SO IN CLOUDY DAYS than hydronics of the past. The newer low-heat-content- water collectors and that CA convection-effect Solar-Siphon newB is very interesting; but less plumbing glycols, etc with an efficient air system (dollar-to-usable: DTU efficiency) comes out UNDER 5000, instlled and you get space heating and can divert blower section for air-cleaning in and out of heating the air flowing; and serves for neat air rotation!
No I have not installed recently, but would like some objective bantering soon.