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Reflecting materials

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Reflecting materials - Light Reflectivity

This table compares different aspects of potential reflectors for the Papasan Chair Solar Cooker:

Material Reflectivity Weight Internet price quote Advantages Disadvantages
Polished Anodized Aluminum ~95% Light ~$7/square foot Reflective, lightweight, can be salvaged, structurally durable, easily flexed and shaped Easily scratched, not super cheap
Mylar >98% Super light $30 for a 4'x'50 roll Super reflective, super light, super cheap Not good at standing up to the elements, forms 'bubbles' if glue starts to give, requires a rigid backing
Aluminum Foil 88% on bright side Super light $3.29 for 1.5'x70' roll Extremely cheap and widely available Not so reflective, corrodes when mixed with acidic juices, structurally weak, would only last one or 2 sessions
Can lids 70-80% (my estimate) Light FREE Widely Available, effective, salvageable, did I mention free?! Not super reflective, non-uniform shape is labor intensive to use
Acrylic Mirror 99% Medium/Heavy $78 for 1'x4' plane Very reflective, nearly unbreakable Comes in plane, likely very difficult to fit to parabola and still maintain reflectivity, super expensive
Glass Mirror 99% Very heavy At least $100/square foot Super reflective, widespread- meaning it could be salvaged Very expensive new, comes in rigid plane- could be broken to fit paraboloid in mosiac in exchange for a precise focus
Astro-foil 76% Light $37 for 1'x50' roll Relatively strong Not so relective


Source

  • Many potential materials with high reflectivity and strength are only available by special order from industrial companies. Though I have not tried to order or to ask for a donation of these fine products, the manufacturers usually deal in bulk.

In addition, I am not sure a special-order industrial super-reflector meets this projects criteria of salvageablility and wide availability. That said, a bulk roll of high quality reflective material may be a wise investment for the aspiring do-it-yourself solar technician.