By Morgan Crook

Posted with permission of the Author and SignBusiness

Ah, summertime. On these sweltering days there's nothing quite like hanging out at the lake with a nice cold beer in your hand. On the other hand, there's nothing quite like standing over the ribbon burner with a hot stick of glass in your hand either. But rather than just shutting down for the summer and heading for the mountains, let's look at some ways to cut down on the amount of time you have to spend standing in front of the ribbon burner.

One option is to use some type of form to bend the glass around. We've all heard of people using relatively complex versions with compressed air to blow the bends out that are making complete "E" s in a single heat, but the time it takes to get everything right doesn't make their stuff very useful to the average neon shop. However, a simple form to cut down on the number of heats or simply reduce the level of concentration can make a job a lot easier. And in many cases the form can be whipped out in just a few minutes.

For the sake of this article lets define a couple of terms;

jigs: surface mounted patterns with little or no "outside" to bends, simply a mold to draw the glass around;

forms: patterns that appear to have been routed, having complete " inside" and "outside" for each bend and for each straight section that joins the bends.

Although there are many similarities in construction and use between jigs and forms, in this article we are going to concentrate on jigs which are more suited to the average neon shop.

Most tube benders have tried wrapping some kind of pattern cloth - Transbestos kind of stuff - over wood to make a simple jig and have been less than thrilled with the results: the cloth falls off, the wood burns, the size of the jig was difficult to get right, and so forth. What is needed is a solid material that won't burn, has a very low thermal conductivity so that it won't lead to stress in the glass, is easy to cut and shape with tools around the shop, lasts a reasonable length of time, and is affordable.

I've tried materials from high temperature plastics (which wouldn't quite take the heat) to glass fiber reinforced concrete (too high thermal conductivity and very hard to shape) and the best results come from a couple of materials that are pretty similar. It is important to point out here the fact that there is a direct relationship between density and thermal conductivity; the stronger and long lasting the jig is, the more stress it is going to impart in your glass due to the amount of heat the mold sucks out of the glass.

One option is available through stained glass supply outlets and is referred to as work surface. It is available in small quanities at reasonable prices (2' x 3' for about $30.00 in 3/8 inch), but it's right at the upper end of densities in my humble opinion. The material I feel most comfortable working with comes from BNZ Materials Inc. (303-978-1199 can get you in touch with your regional distributor) and is available in three hardneses: