Collectors get a charge out of glass insulators

They have to rank as one of the more esoteric categories of collectibles.
Glass insulators, those crown jewels that sat atop electrical poles preventing leakage of current, have become dear to many collectors. The most valuable examples can fetch tens of thousands of dollars.
“It’s a lot more complicated than people would think,” said Jill Meier of Carlisle, Mass., publisher of the Yankee Polecat Insulator Club newsletter.
A current price guide lists more than 9,000 different insulators for collectors to pursue. When examining an insulator such questions as, “Does it have an umbrella or a saddle groove?” and “How many petticoats are underneath?” arise.
There’s a lot to know when collecting insulators, but with a few key pieces of information and a support group, such as a local club, it can be an electrifying experience.
Despite the thousands of types and the specialized terminology used by collectors, Meier believes insulators are rather straightforward when compared to other such other collectibles as stamps and coins.
Three keys to unlocking an insulator’s value are its shape, the embossing, and its color. The smallest variation in these three factors can distinguish an older, rare insulator from a more common, perhaps more modern, counterpart.
For example, a clear Babson Bros. surge insulator can go for less than $5, but a few examples of a rare variation are known and can fetch up to $3,500. Insulators made of Pyrex carnival glass can range from $80 for an interesting example to $3,000 for the rarities.
Beehive, candlestick, fog bell, pogo and snow cone are just a few of the shape names collectors’ use. To eliminate confusion, the hundreds of different shapes are identifiable thanks to the Consolidated Design (CD) numbering system.
A “bullet” insulator may be advertised for sale, but the term is commonly applied to three different shapes. Is it a CD 132, CD133 or CD 133.4?
Whether collectors are shopping through magazines, on the Web or over the phone, use of the CD number makes sure everyone is speaking about the same shape insulator.
Embossing can help determine an insulator’s age. A patent date or style number add even more assistance.
The first insulators were made in the 1850’s. According to Meier, older insulators look cruder, and the embossing appears hand-written rather than machine stamped.
“The making of glass went through transitions over the years,” Meier said. “Insulators follow these transitions, and experienced collectors get to know the nuances of old glass,” she noted.
Finally, the basic colors — greens, aquas, blues and ambers — branch into thousands of colors that can be swirled, streaked or have bubbles throughout.
Most insulators are aquamarine because of the small amount of iron present in the sand used in the glass manufacturing process. Other colors were created to code circuits, since a single pole may have contained up to 200 separate wires.
Newer insulators are threaded, but older examples are threadless. Threaded insulators screwed onto a pin. Some common examples are shown below. This lot recently sold at auction for $80. Threadless styles tended to get stuck on the poles and break.
Insulator expert W. H. (Ted) Ingram offers his top ten tips for collecting on the web site www.insulators.com. His advice includes developing a mentor relationship with an experienced collector when starting in the field.
“The experienced collector can offer advice in the form of education, and advice about what pitfalls to avoid,” writes Ingram. “When I was a new collector, I was fortunate to have several established collectors to buy insulators from at attractive prices, to volunteer general information and advice, and to answer questions.”
His recommendations for building a collecting include joining insulator clubs, attending conventions and swap meets, and specializing in one category.
It has been 30 years since the last major glass-insulator manufacturer ceased production. The glistening domes with nicknames like Mickey Mouse, Blob or Frog Eyes have nearly all been replaced by insulated cables.
Though technology has pushed them off the poles that line highways and biways, today these bits of antiquity have become an electrifying hobby for thousands of collectors.
Copyright 2002 by Krause Publications. For a free catalog of Krause Publications books or periodicals on collectibles, write Public Relations, Dept. IC, Krause Publications, 700 E. State St., Iola, WI 54990-0001, visit www.collect.com on the worldwide web, or e-mail info@krause.com.