Chemical spills in the hood are not uncommon. If the hood has a cup sink in its floor, liquids can escape into the drain before they can be cleaned up. This is poor practice and may lead to legal liability (1). Plugging the drain avoids this problem but prevents use of the drain for, for example, a condenser coolant or an aspirator.

A dam of gasket material around the sink can resolve the difficulty. Frost King vinyl gasket, commercially sold as weather strip, works well (2) The vinyl gasket is composed of a tube (∼1/4-in. cross section) with a ∼1/2-in. flange tangential to it. A portion of the gasket is cut to fit the sink circumference and the ends joined by a short length of 4-mm glass rod, with the tubing body on the outside of the ring formed and the flange perpendicular to the ring (the way it forms naturally). The flange is then simply inserted into the sink until the tube rests on the top edge. The material’s natural springiness holds it in place.

This dam will prevent chemical spills from reaching the drain. It is readily fabricated and inexpensive and thus expendable if damaged or embrittled by age and exposure. It can be readily removed to allow floods from burst tubing, and so forth, to drain from the hood floor. The top of the small-diameter tubing remains below the lip of the hood floor so unattended condenser coolant leaks will go over the dam before they spill out of the hood.

Literature Cited

1. 25 Pennsylvania Code 91.34 (a) (accessed Oct 2006).
2. Frost King Weather Strips (accessed Oct 2006).