An Inexpensive, Yet Strong, Way to Assemble Aluminum Rod Lattices

Aluminum rod lattices (monkey bars) in fume hoods and on bench tops are a standard means of setting up reactions and apparatus.

C12 nylon tie @a. 3116'~ 14' In our organic chemistay teaching laboratory angtnal dimensions) we recentlv constructed six nortahle bench-ton . ~~~~ .~ lattices. he total con.stmerion cost nf these units would have k e n prohibitive had we pur- chased and used traditional lattice nuts from a scientific supply company (list prices ca. $8-15 each). Our lattices feature conn&tions between vertical and horizontal members as depicted in the figure below.

The connections are made by wrapping each 1/16" - 1/81 layer of parefilm of the intersecting rods with a layer of parafilm

112" aluminum rod T4 (ca. 1/16 in. to 118 in. thick), overlaying the rods, and fastening them with two inexpensive C12 nylon ties (ca. 3/16 in. x 14 in. original di- mensions). The excess tongue of the nylon tie is

easily snipped off with metal shears or a strong scissors. Connections of this sort are surprisingly strong-the author (145 lbs) stood on a two foot span of aluminum rod, c o ~ e c t e d at each end to ring stands, for two minutes and observed only U 8 in. of slippage of the horizontal spanning md down the vertical members of the ring stands. In addition, the pressure on the intersection point causes the two paraf~lm layers to fuse such that the rods do not rotate. The cost savings is tremendous considering baga of nylon ties (26100 count) can be purchased far only $2- 4 at hardware and building supply stores. (Incidentally, to build our portable lattices, we purchased 120 R of U2-in. extruded aluminum rod for a mere $79 versus a list price of $400-600 for the same quantity in science supply catalogs.)

Ronald G. Brisbois Hamline University

1536 Hewitt Avenue St. Paul, MN 551 04-1 284

506 Journal of Chemical Education