A Handbook for the Recognition & Identification of


Many of the same alteration techniques previously described for glass insulators also have been applied to porcelain insulators. This section will deal with those alterations which are specific to porcelain insulators.

Color Altered Specimens

In terms of color alteration, two primary techniques have been identified. First, there are a number of specimens floating around the hobby which have been reglazed. This process involves the application of standard ceramic glazes to existing pieces which are then refired in a kiln. This can produce glazes of high quality which are difficult to discern as not authentic. In the case of the three ponies in the photo below, the glazes are very uniform and smooth. Absent the gold leaf marking left by the reglazer, the only way to tell they are altered is to look inside the skirt and pinhole of the insulator which retain the original white glaze and which reveal the sloppy over brushing of the new glaze onto the original white surface. Had this area been also reglazed, it may be impossible for the average collector to detect the alteration. In the third photo there is a strange purplish piece along with a mottled red and black specimen. The glazes in these two are not uniform like the previous photo and can be identified as potentially altered by the mottling and crudeness of the glazes. Unfortunately, there are some pretty crude factory specimens which are equally uneven and blotchy so this is not a fail safe indicator. If a color appears to be to good to be true, it just may be.

Reglazed white porcelain insulators.


The undersides of the above three pieces reveal their original white glaze and evidence of added color.


Reglazed white (L) and brown (R) porcelain insulators.

The second method of color alteration actually involves the use of metallic oxides similar to those used in "carnivalizing" glass insulators. These materials are readily available in the ceramic hobby. The following photo shows two insulators which were treated with such metallic coatings and fired in a ceramic kiln. Because the inside skirts and pinholes were coated, it is not easy to discern the original color with a visual inspection.

Brown porcelain insulators with carnival coatings.

Fabricated Specimens

It is relatively easy for even novices to create a ceramic mold from which a porcelain insulator replica could be cast. It’s then a simple matter of firing and glazing to produce a convincing counterfeit. The photo which follows is a pony style porcelain piece marked: BOSTON BOTTLE WORKS. It has what appear to be standard threads and is similar in dimension, color, and shape to known porcelain specimens. Only well informed collectors are aware that Boston Bottle Works only made glass insulators so it would be easy for beginners to be fooled by this piece. In addition to the unsubstantiated embossing, the crude texture of the porcelain and glaze and the thin skirt walls could give rise to suspicion but probably only to experienced porcelain collectors. The best guide for detecting such frauds is access to and use of books on porcelain which identify known embossings, colors and styles.

Fabricated porcelain insulator marked “BOSTON BOTTLE WORKS”

Repaired Specimens

As with glass insulators, a variety of methods have been employed to repair porcelain specimens. The techniques include regluing, filling chips and gaps, and major reconstructions. Because of the relative ease of use of the wide range of putties and other filling compounds, porcelain repairs are much easier to achieve than with glass. Covering the repairs is also easier with porcelain than with glass. From painting to a complete reglazing, repairs are easily concealed if done carefully. The only techniques to discover such repairs are to scrutinize the entire insulator for any differences in surface color and/or texture, or irregular shapes such as the crude reconstruction seen in the upper half of the following photo.

The entire upper half of this Cutter has been reconstructed from clay.

Hybrid Multipart Specimens

Porcelain multipart insulators consist of a series of from two to four shells cemented together with different materials including sulfur and Portland cement. Two primary types of alterations are possible with these pieces. The first is to replace a damaged skirt or skirts with undamaged matching skirts from another insulator of an identical style. This would result in an “authentic” insulator insofar as it consisted of original factory parts but it would still be considered altered and would not retain the value of a completely original specimen. The second alteration which has been detected in multipart insulators is the mixing of skirts from different insulators to create a hybrid which is different from known styles. While this may be done as an amusement, the potential for such pieces to filter into the market and be misconstrued as authentic is very real.

In the early Locke specimens, where sulfur was used as a cementing agent, it is not to difficult to detect skirt swaps as producing the same sulfur cement is not easily done. In specimens with standard Portland cement seams, it can be extremely difficult to detect replacements especially if the piece has been exposed to weather. When there is a significant difference in color or texture of the cement between different skirts it is not conclusive, but the possibility of alteration should be considered. In the case of hybrid pieces, reference to literature which documents the existence of known styles is the best protection. Most styles that are published have been traced to catalogues and journals which corroborate their authenticity. Once again, knowledge is the best guide.

Section 4
Section 4