Goethe glass
Goethe glass is a type of glass that is used for the restoration of historical glass windows. It is named after the historical glazing of the Goethe House in Frankfurt .
properties
Goethe glass is a flat glass with a slightly structured surface that resembles the uneven surface of historical glass panes from the 18th and 19th centuries. Until the First World War , ordinary window panes were manufactured exclusively using the mouth-blow molding process, which gave them a slightly uneven surface. It was not until the 1920s that the blow molding process was replaced by the mechanical extraction process . Goethe glass was initially also hand-blown, but is now also manufactured as machine-drawn glass. It is available in various thicknesses and is bubble-free. By default, Goethe glass is a colorless glass, although some glaziers also offer tinted versions. Bluish or greenish tinted Goethe glass is often referred to as forest glass, which is actually the name for historical glass made in forest glass works and tinted green with iron oxide .
Goethe glass is also offered under the name Chateau blanc .
use
Goethe glass is used for the restoration and protection of historical windows.
On the one hand, it is used directly as a replacement for the original glass pane in historical window frames. The slightly structured surface makes it similar to the historical window panes, so that the new window panes fit harmoniously into the image of the facade and the overall visual impression of the building is retained.
On the other hand, Goethe glass is also used for external protective glazing in historical church windows with lead glazing or glass painting . A protective glass pane is inserted into the frame instead of the original pane. The original iron systems are extended inwards by a supporting structure on which the historical pane is attached at a distance from the protective pane. The protective pane takes over the function of the room closure and protects the historical window from weathering by air, rainwater and UV radiation as well as from pollution. At the same time, the external glazing creates a seal against cold, drafts and noise.
Due to its slightly structured surface, Goethe glass does not reflect in contrast to conventional industrial glass panes ( float glass ), so that the effect of the historical windows is not impaired when looking from the outside. Since Goethe glass has no color inclusions, the glass colors of the church window are not falsified either when viewed from the outside or from the inside.