Museum conservation
The art of restoration is a specialty given to people that are devoted and passionate in their field of interest. All finding pleasure returning something to its former condition and function rewarding. With glass restoration there are limitation in the expectation of visual repairs. Dishware, stemware and some glass sculptures can only be displayed and no longer used. There may also be other limitations and conditions after the restoration is completed depending on the subject being restored. While I’m not involved with restoring 800 year old one of a kind items. The process is identical were your trying to conserve as much of the original and introducing as little newer material as needed. In my lighting work I have found my glass resources are becoming limited and the practice of conservation becoming the norm.
Glass restoration - Cast - Crystal - Painted - Colored
By- Len Daley
Restoration of glass is very popular using non yellowing optical bonding process. You can google some of the museum restoration companies for the process which takes a special skill set that I also perform . The results on crystal cut glass work are impressive in most cases looking like a hair or the line between bifocal lenses when the break is clean. On painted glass the results are more noticeable because the paint along the crack is missing or scalloped. Often because the paints are on the inside of a shade a sliver of light is visible at the breaks. Very small or missing fragments are not reused. On colored glass the results also look like a hair on the glass depending on the color and or textures. Areas where chips of glass and fragments are missing will be visible and filled in with the bonding. Structurally after my work is completed the glass shades are extremely strong, secure and functional again. The pictures below clearly express the minor lines with some of the wide uses of bonding glass.
Clients need to understand a little bit about the technical aspects of glass. The nature of glass in most cases express the transmission of light going through it. As light travels the glass absorbs some of the lights rays holding or letting the light traveling through the glass. Any obstruction to the original molecules when the glass was created will obstruct the traveling light and reduce the original clarity. When expressing the process to clients I will often say “even diamonds have flaws”. Again my work is strictly related to lighting only.
Discontinued COLORED slag glass colors – This is just one of the reasons why glass conservation is performed. Over the past 50 years that I have worked in glass I have seen many glass companies and rare glass colors disappear. Just recently one of the last manufacturers from 1880’s stopped making glass in 2018. Having their glass furnaces turned off will put more demand on glass restoration and less on glass replacement. The example below shows what I’m trying to explain. Basically in this example your looking at a five color slag glass discontinued back in the 1940’s. The options in this case are limited to custom bending a best matched color or using a chemical optical bonding process very similar in dental work. Below is an example of a discontinued slag glass mix.
CAST Glass- being a glass formed in a mold. It tends to be a thicker glass say 1/4″ thick and formed to hide light bulbs. Antique cast desk lamps are popular and occupationally I get bathroom fixtures to restore. Below are just a few examples of cast glass repairs.
Crystal and clear glass globes. Examples below
Cast glass with reverse glass painting on the inside. (Handel)
Cast glass globe with reverse glass painting