William A. Bonner
Stanford University Stanford. California
ONE
A Useful Glass-blowing Lathe for Small Equipment
of the principle difficukies in at,taching a glass joint, or tube to a spherical glass surface, particularly when an accurate common axis with an existing aperture is required, is the precise alignment of the new aperture with the existing one. This problem is solved in the professional glass-blowing shop by t,he use of a glass-blowing lathe, a machine item which is not ordinarily available in the laboratory to the practicing chemist who has an immediat,e, small glassblowing job with such requirements. In connection with meetiug the latter need, we have found t,hat the uow commonly employed vacuum rotary evaporator (e.g., Rinco, Model 1007; Labliue, S o . 5100) serves as a useful and satisfactory small glass-blowing lathe. This piece of equipment, provided with a metal standard taper joint which rotates a t about, 75 rpm, has an out,let arm (i.e., the vacuum take-off) which is perfectly suited for the attachment of a rubber tube suitable for hlowing an attached piece of rotatiug glassware. The use of a rotary evaporator in this capacity with a hand-torch or stationary glass-blowing burner readily insures the location of a proper sized hole accurately aligned with the existing standard taper neck in a flask or other piece of apparatus which is being modified. The use of carbon shapers with such a simplified glass-blowing lathe permits the construction of completely symmetrical in-line holes of any desired
402
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Journal o f Chemical Educotion
reasonable size, as well as the very simple alignnleut of tubes or joints attached to such holes.
The fact t h a t a rotary e\.apomtor may hc mounted on a ringstand wit,h its axis of rotat,ion immediately adjustable from a horizont,al to vertical position gives this piece of equipment a working versatility not shared by larger, commercial glass lathes. The accompauying photograph illustrates the use of a Rinco rotary evaporator as a small glass-blowing lathe in the horizontal position.
