A Novel DryingBtorage Rack for Volumetric Glassware Small volumetric flasks and graduated cylinders are easily tipped over during washing and drying manipulations. Further, they are difficult t o drain without possibly introducing contamination. To overcame these problems, a drying rack was designed and constructed to accommodate a quantity of assorted volumetric flasks. On this rack volumetric flasks and )graduated cylinders are hung between parallel rods with the tops inverted (see Fig. 1). The advantages offered by this rack are rather obvious. The volumetric glassware can he conveniently drained, dried, andlor stored a t room temperature without fear of dust contamination. Air or oven drying of volumetric flasks in an upright manner can concentrate water .residues. The glassware is hot when removed from the oven, small flasks are easy to tip over, and tops are open to any airborne matter (i.e., minute dust or rust from old ovens). Burfield and Hefterl described their findings on oven drying of volumetric glassware and the effects on dimensional stahility. Air drying of inverted glassware on a drying rack removes any doubt about dimensional stability, there is less handling of the glassware, there is Less chance of introducing dust into the glassware, rods do not penetrate the flasks or cylinders, an oven is extraneous, and the flasks can be stored on the raek until needed.
The drying/storage raek can be qukkly made from wooden dowel rods and inexpensive plywood. The left-hand figure shows s partial front view of the rod and flask arrangement on the board. For flask sizes between 10 mL and 250 mL the dowelcenters should he 2.5cm apart, and for flask sizes between 1W mL and 1000 mL the dowel centers should placed 4.5 cm apart. Another row of this same dowel arrangement can he placed beneath the first to accommodate another row of flasks. Averticalspacing of 20 cm hetween rows is adequate for IW-mL volumetric flasks. It helps to lay the unmarked plywwd flat and place a few pieces of glassware upon the flat wwd surface. From this layout the vertical and horizontal spacings needed are easily ascertained for a custom-designed rack with as many rows as desired. The right-hand figure shows the oartial side view of the rack with flasks. The dowels were inserted into holes that were drilled with an 80° anele hetween &h mod and the too of the hnckhoard of the lack hut anelid &from lothe sides. Dowels ~~-of Ydin. X 8 in. were .uskd ~for support dsmaller flnaks.Thisallowed three 100-mLflaskoto be hung on thesame pair of rudsasshown.The backboard was made from a piece of eaterior-grade .$-in.X 24-m. X Win. plywmd. The assembled rods and board were glued with a wood glue. In this case Titebond Wood Glue was used toglue the dowel rods in place. Theassembly was allowed todryovernight. An aerosol can of white paint was used to spray paint the rack before mounting it to the wall. Only external parts of the glassware come in contact with the rack, and a contamination-free arrangement holds the ohjecta until they are needed again. ~
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Burtield, D. R; Heiter, G. J. Chem. Educ. 1987,64,1054. Howard P. Wllllams and Fellcla B. Graves University of Soumern Mississippi Southern Station Box 5043 Hattlesburg. MS 39406
Volume 66
Number 9
September 1989
771
