The Dirty Business of Clean Water

Bruno, our resident water expert, is on his way out in a few weeks, so his priority at this point is to transfer his knowledge to a new volunteer in order to preserve the momentum of his work.  Lucky me, I get to be the sponge.  Today, Bruno was ready to build the beta model of the water filter he's designed over the course of the last 6 months, so Francois and I got to go along and help him out.

	Here are the pieces of the mold we will use to pour the cement into.  The filter is essentially a long skinny cement bucket filled with sand.  The piece on the left is the "center" of the mold, and the other two are the sides.  These are made of steel, and extremely heavy.
	We had to create a kind of "spout" that would carry the water at the bottom of the bucket through the cement filter out to the other side.
	Before pouring in the cement, we had to make the mold extremely slippery with lots and lots of grease.  Yumm.
	After mixing together the right proportions of sand, cement powder and water, we started dumping it into the mold.  Every so often we'd stop shoveling and push a dowel down the sides to help settle the cement.
	In order to settle the cement some more, we had to hammer the outside of the mold a bunch.
	Leveling off the cement... The 'top' of the whole thing here is actually the bottom at the end of the day, so we had to make it as level as possible.