In the states, we have a show called Shark Tank. This was on sometime back= .... https://www.oneearthdesigns.com/ Similar in concept to what your looking for? -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of= Denny Esterline Sent: Wednesday, May 30, 2018 7:57 AM To: Microcontroller discussion list - Public. Subject: Re: [OT]:: Making a "quick, easy & cheap"* reflective finish. May or may not be useful, but I seen at least application of using Mylar sp= ace blanket with edge secured and partial vacuum on one side to create para= bolic reflector. Definitely cheap/light/simple, may not be rugged enough fo= r anything past experimentation. On Wednesday, May 30, 2018, RussellMc wrote: > I have acquired a number of parabolic "satellite dishes" dishes (6 or=20 > so all up) which I wish to 'play' with as solar concentrators. > I'm interested in suggestions for reflective coating methods not on=20 > the list below and for comments by people familiar with these methods. > "Spray chrome" seems attractive if it works "half well". > > Aim is investigation of cooking, water heating and water sterilisation. > Purpose is evaluation of practicality for developing country use. IOF=20 > the 3.3m dish proves useful it could grow a solar tracker (fairly=20 > easy) and may even be useful in personal applications. > When used with a counterflow heat exchanger the water sterilisation=20 > capacity should be 5 to 10 times as much as water heating throughput=20 > at a given temperature. > > Intention is to gain practical knowledge - if anything practical=20 > results from this construction methods may well be quite different. > > Dish sizes are from about 300mm through about 1m dia in steel, 1.5m=20 > dia in Al and a 3.3m dia Al mesh dish. > [Mesh dish proper is very light. Dish dismantles to 8 panels which can=20 > be carried easily by one person wrt weight. Shape a bit annoying :-)]. > > I wish to coat the surfaces with an optically reflective layer so as=20 > to provide concentrated solar energy at the focus. > Ease of coatings and not much cost are rated ahead of efficiency - but=20 > high efficiency is a welcome bonus. > > Flatness of surface and lack of 'bumps' not too too critical - these=20 > spread the focus point but this need not be as tight as in RF application= s. > > The 3.3m dish is about 8 m^2 in area. In full sun at 50% efficiency=20 > would give about 4 kW. Useful :-). > > The mesh dish will need to be filled with a filler of some sort and=20 > sanded to a smooth surface - not too hard (ha!) The largest solid dish=20 > is Al and MAY sand to an adequate surface as is with eg a clear spray=20 > on coat to reduce ongoing oxidation. > > Possible options are: > > - 1. Adhesive backed aluminised mylar foil./ Less available here than=20 > in US. > > - 2. Non adhesive backed aluminised mylar foil - more available here. > > - 3. Space blanket - similar to 2. but usually more wrinkled from=20 > folding than desired. > > - 4. Al cooking foil (non adhesive backed). Cheap, available, lower=20 > reflectivity > > - 5. Spray on "fake Chrome. Goodness tbd > > - 6. "Real" chrome plate - commercial - even done with minimum effort=20 > cost is highish.s > > - 7. Real chrome plate DIY - doable but high effort. > > -8. Other chrome imitators applied by eg tumbling. Dearish but cheaper=20 > than chrome. > > - 9. Al surface sanded and clear coated. > > - 10. Front surface silver mirror using silver nitrate + clear coating. > (Cost may not be TOO high. Result superb if doable). > > - 11. Small mirrors or broken mirror material stuck on surface.=20 > (Smallest focus size is about the same as mirror size and mirrors not=20 > sitting exactly at dish angle beneath them will further degrade focus=20 > area minimisation. ) > > > Comments / ideas ??? > > > > Russell > > * "quick, easy & cheap" - choose any three. > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive=20 > View/change your membership options at=20 > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .