Appendix

Appendix A

Preparing Drawings

for a Technician

A.1 The Problems with Requests to Glass Shops*

There are many brilliant men and women who are excellent teachers and scientists, can analyze the most complex data, and can draw the most complex molecules or mathematical equations. Yet, many of these same people cannot communicate the shapes of even simple items on a piece of paper. In addition to this complication, when an object is made of glass, new complications are created. These newproblems typically derive from thefact that working with glass is like working with no other material on earth. Thus, the average person will tryto rationalize construction with materials they are more familiar with, such as wood or metal. In addition, it is unlikely that this average person will have had the opportunity to learn theparameters andlimitations of glassware construction.

I am in no waytrying to belittle the problems that machine, wood, or electrical shops have with poorlymade or inadequate drawings. However, sawing, turning,

J l

Fig. A.1Examples of requests to a glass shop.

* As a glassblower, I am most familiar with the specific problems encountered with requests to a glass shop. Regardless, these frustrations are shared by all whorequest custom items for construction.

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gluing, soldering, drilling, and cutting are common terms that are understood by most people. The terminology of glass is different: Fire-polishing, fusing, blowing open a hole, and spinning a base are as foreign to the average person as the tools used. Because of misunderstandings of the tools and operations used with glass, what a person asks for is often not what they want. Over the years, I've had requests for "drilling a hole in a tube and sticking a tube over the hole in the tube so that material could go several ways" or "welding a flat glass plate on the end of a tube so that it could stand up." In these two examples, what the requestors wanted were a "T" seal and a base to a column, respectively (see Fig. A.I). If I had done exactly what was requested, the costs could have been phenomenal.

A.2 Suggestions for Glassware Requests

Whether you have a glass shop in your facility or send your glassware requests to an outside glass shop, you should limit your requests for what you want and not state how to do it, because this will save you time and money. By simply stating what is wanted, providing necessary dimensions and related construction materials, and avoiding discussions on how to make the item, much time and confusion can be avoided.

The Sketch. Prepare a reasonably accurate sketch. You do not have to be a draftsman or an artist. However, you are not a two-year-old child with a crayon. It is likely that the more time that the glassblower spends on trying to figure out what your drawing is trying to represent, the more you will be charged.

The Measurements. Measurements should preferably be given in centimeters (or millimeters). English measurements are not recommended, and tenths of English measurements are not acceptable.

Tubing Identification. Commercially available tubing is only available in metric sizes. These tubing sizes are shown in Chapter 3. American-made mediumand heavy-wall tubing is made to English measurement dimensions, but are now listed in metric equivalent sizes. For example, 1-in. tubing is listed as 25.4 mm. Commercially available sizes (both metric and English) of medium and heavy wall tubing are shown in Chapter 3.

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Fig. A.2 Examples of complete joint identification.