Laboratory Jacks of Local Construction Laboratory jacks have become an integral and important part of modern lahoratory apparatus and because their use contributes to good safety practice, they should be part of the apparatus fm undergraduate instruction. Lab jacks are strongly recommended in undergraduate organic lahs since hot objects (oil baths, steam baths) are manipulated. Commerical laboratory jacks are expensive. Some savings can he realized through shop modification of automobile scissor jacks. Those made from US.scissor jacks are less convenient than the commercial ones since the profile is higher (11 em versus 7.3 cm) and they are considerably heavier (6300 versus 2060 g). However, they are sturdier, last longer, and extend to a greater height (38 versus 31 cm). Recently we became acquainted with foreign car (Datsun and Toyata) jacks. These jacks are lighter (3350 g), have a lower profile (7.5 cm), and have less tendency to wohble when fully extended (37 cm).
The steps in modifying a scissor jack to that shown in the figure is to remove the superslructure, mount 'Isin. X 20 cm X 20 crn aluminum or stainless steel plates a t top and bottom, and afix a handle. We have also mounted large ruhher stoppers
(size 12-14) as handles but currently prefer either of those shown. The lower plate may be omitted since the stability seems adequate. We experienced no difficulty in huying inexpensive, used jacks to huild modified jacks, as shown in the drawing, a t about one third of the cost of commercial ones. We thank Messrs. Richard K. Gruhlkey and Floyd H. Vulgarnore for their help in the construction of the lab jacks.
Oklahoma S t a t e University Stillwater. 74074
606 / Journal of Chemical Education
E. J. Eisenbraun Heinz Hall
