$1 solar pasteurizer plans

[tsponheim at igc.apc.org]

I have some urgent information that I need to get to the
suffering people of Iraq:

It was not known until very recently that water can be
pasteurized in a cardboard box.  This could immediately provide a
great deal of safe water for as little as US$1 per solar
pasteurizer.  Construction time is about 1 hour.  Materials
needed: one cardboard box and some extra cardboard pieces, 3-4
meters of aluminum foil, glue or tape, plastic wrap.  Tools
needed: a knife.

1)  Find a cardboard box, the larger the better.

2)  Cover the inside of the box with aluminum foil.  It can be
    glued (with carpenter's glue or wheat paste) or taped into
    place.

3)  Fold the flaps into the box to form a double wall.

5)  Foil the exposed side of the flaps in this position.

6)  Cut a piece of cardboard just big enough to fit down into the
    opening of the box.  Foil it.  Then paint the foil black with
    any black paint (ashes will work if no foil is applied). 
    This piece will act as a false bottom.

7)  Cut a few strips of cardboard and glue their ends together
    forming a hoop.  These hoops should be just tall enough to
    support the false bottom at about the height of the end of
    the flaps. 

8)  Place the hoops into the box and insert the false bottom
    piece.

9)  Cut a piece of plastic wrap big enough to fit over the
    opening of the box with a 5 cm or so overlap.

10) Tape this piece down to form a tight seal on top.  You will
    be removing two sides of this plastic in order to put water
    containers into the oven so before you tape it down, apply a
    layer of tape onto the outside of the box so that the tape
    that attaches the plastic will adhere to tape and not to
    cardboard.  In this way, it can be removed and retaped many
    times.

11) Make a reflector by cutting a large rectangular piece of
    cardboard to the size of the top of the box, but longer by
    10-20 cm in one direction.  Foil this piece on one side.  Lay
    it on top of the box with the foiled side down.  Fold the
    overlap down and glue the overlap to the side of the box.  

12) To pasteurize water, place a few liters of water in dark
    covered pots or jars painted black with lids.  Water is
    pasteurized and safe to drink after it has reached 65 C for
    1/2 hour.  If no thermometer is available, signs of boiling
    can be ascertained to determine that the water has neared 100
    C.

A pictorial version is available through Solar Box Cookers
Northwest.  Contact me through one of the following means and I
will mail or fax them to you:

Tom Sponheim
Solar Box Cookers Northwest
7036 18th Ave NE.
Seattle, WA 98115 USA
Voice/Fax: 206/525-1418 (auto-switcher)
Telex: 1503097451
Econet:tsponheim