Old Wavy Glass Window Panes That Have Spots & Haze

Wavy Glass

• The distortion noted in old glass panes has less to do with its age than it does with the era and style in which it was manufactured. Hand-blown glass takes on the striations and irregularities of a hand-crafted piece of work, as is the case of crown glass. This glass was blown into a molten bubble through a straw by the glass maker, then stretched by another individual on the opposite side. The straw was broken off and paddles were used to form the glass into a sheet. It was spun like a pizza dough to finish out the process before being cooled and cut into panes. The spinning of the glass resulted in inconsistencies that appear as waves and ripples in the finished product.

Bull's Eye

• Crown glass contained a bull's eye, a thickened round area where the blowpipe, or straw, was attached. While this defect was generally discarded, when glass was at a premium, the bull's eye was often salvaged and used for barn windows or transoms. The bull's eye cannot be seen through, but did allow in light, and was used accordingly to eliminate waste.

Pits and Haze

• The natural weathering of glass over time causes pit and haze defects. Some haze may be polished out using a mild abrasive like toothpaste. Pits, however, are a permanent fixture. If the purpose is to have a window through which you can see clearly, replacement in any of these instances may be your only option. However, preservation of these artifacts is often far more satisfying. The unique qualities of old glass tells the story of its history, and is something that should be preserved.

Myth

• Once thought to be an ever-changing material in a constant state of flux, glass is not, in fact, subject to the phenomenon of “flow.” Due to colonial glass panes often being thicker at the bottom than the top, it was widely believed that the glass continued to flow after being hung, and therefore settled to the bottom of the pane. The reality was much less fantastic. It was due to the manufacture of the glass by hand, making a consistent thickness difficult to achieve. When the panes were hung, often -- but not always -- the thickest, heaviest part of the glass was placed at the bottom.