Construction of Corrosion-Resistant, Inexpensive Lab Lattices Lahoratory lattice frameworks of noncorrosive PVC pipe and fiberglass rods can he custom-huilt t o desired size and location using commonly available materials and tools a t less than half the cost of manufactured metal frameworks. PVC pipe and various PVC connectors are available from local plumbers' supply or hardware stores. Three-inch diameter PVC pipe was used tq give the required rigidity, hut 2-in. pipe probably would have done as well. The pipe was available only in 20-ft lengths, necessitating the purchase of approximately 16 excess feet, and the pipe glue came only in a quart size when a pint would have more than sufficed. These extras raised costs and might have been avoided by more extensive shopping around. Half-inch diameter fiberelass rods of various lenzths (from 1 f t to 8 ft. in black or "If-white) IVCW P ~ r c h a d f r o mACE Class ~ o m p & l ~ are t also arailat,lt from S1hma Chemical Company. Alwnlntun lntricr cormertun (with Allen hru head setscrews) were ourchnsed from Thomas Scicnt~fir ~~~~~~~~-~~ Cornom\,. r-~-,One PVC-fiberglass lattice was floor-mounted over a lab table and measured approximately 8 ft high by 6 f t wide, containing six vertical and five horizontal rods connected a t cross points with 30 lattice connectors. Its total cost was about $240. Another lattice was mounted on a lab bench top (see photo) and measured approximately 6 f t high hy 8 ft wide containingeight vertical and six horizontal rods connected with 48 lattice connectors. Its total cost was about $295, The PVC pipe farmed the rectangular frame of the lattice and support for the connecting rods. The pipe was cut to size with a n ordinary hacksaw, sawing around a measured line t o create a guide channel before cutting through the pipe. Standard PVC 90' angle connectors were used t o join the two sides and top of the frame. PVC T-connectors, with an additional 3-in. opening maehine-drilled in the center, were used to connect the sides to the hottomof the frame and to form short leg supports perpendicular to either side. All parts of the frame were fitted together first t o insure proper dimensions before final gluing. After measurements for the appropriate number and position of horizond and vertical rods had been made, 'h-in. holes were hand-drilled, with an electric drill, an the inside only of the PVC pipe frame for insertion of the fiberglass rods. The holes were drilled off-center in order to accommodate the crossing of the rods in the lattice. The fiberglass rods were flexible enough to be bowed in the middle when inserted into the pre-drilled holes. The rods were then clamped with aluminum lattice connectors a t each intersection where horizontal and vertical rods crossed, thus providing a very sturdy, nonflexible framework. The finished lattices were secured to the lab bench with bolted pipe straps and further reinforced by supports clamped between the frame and overhead building girders. Finally, electrical outlets weie attached to the frames. The lattices are strong, noncorrosive, do not vibrate, can easily be moved if necessary, and can he huilt in a day by two persons. Manufactured metal or fiberglass frameworks are available from several supply companies in a variety of sizes. Sizes comparable t o the two lattices we built cost about $650 or mare each and were wall-mounted kits for which no wall space was available in the laboratory. A quotation from a local manufacturer for a smaller 5 X 5-ft aluminum channel frame, with five horizontal and six vertical aluminum rods welded together, t o fit on a bench, was $450 plus a hefty delivery charge. Therefore, the home-built PVC-fiberglass frames are much less expensive and should last longer. We gratefully acknowledge students William Wetmore, Greg Perez, and Adam Bright for helping to build the frameworks along with the assistance of the University of Miami engineering machine shop. ~
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George H. Fisher Arthur Levin Eugene H. Man University of Miami Coral Gables, FL 33124
Volume 62
Number 9
September 1985
819
