Thursday, June 7, 2012

Update on solar oven....

We discovered that we had done a little of the math incorrectly.  Elliot has now re-cut the ribs using the CNC laser cutter.  (Yay for easy technology!)

I originally asserted that bare aluminum was specular enough for building a concentrating collector.  I now think that is only partially true.  Investigation with a laser pointer suggests that the "brush marks" on the surface as it came to us allow an estimated 50% of the energy to be perfectly reflected.

I have therefore been polishing our panels.  This produces a mirror-like surface, but with "swirls".  I've worked about an hour on each of three panels (about 2 square feet to a  panel) and not started the fourth.  I think with additional labor, or better equipment, such as a car buffer, a truly mirror-like surface can be achieved.  (I'm just using a drill right now.)

Hopefully this weekend Elliot and I will get to do a true test.