I would suggest using glass.  It's cheap, it is easier to clean than
plastic, much more resistant to abrasion, and is a measurably better
substance than plastic for the purpose of trapping radiation inside the
box.

Depending on how much was you intend to process, you wish to consider
insulating the box.

On Tue, 21 Aug 2001, Allen Dick wrote:

> I am thinking of making a solar melter.  I understand that the design is
> nothing particularly difficult, but I wonder if there is any necessity
> to use glass on top, or if plastic will work as well -- assuming it does
> not melt.

---------------
Richard Yarnell, SHAMBLES WORKSHOPS | No gimmick we try, no "scientific"
Beavercreek, OR. Makers of fine     | fix we attempt, will save our planet
Wooden Canoes, The Stack(R) urban   | until we reduce the population. Let's
composter, Raw Honey                | leave our kids a decent place to live.