A NOT-FOR-PROFIT CORPORATION

Restoration Process

How a complete restoration is performed

Mr. Edward Dehors, the Foundations founder, personally works on each and every restoration project! When an extra hand is needed an apprentice is always willing to help and learn.

To correctly restore a stained glass window to its exactingly original condition requires a basic step by step process as follows...

#1 TRANSPORT

After the panel or window with is removed from the structure it is safely transported in a foam-lined plywood case(s), built to exacting size, to eliminate further damage in transit. Usually the panels or windows are placed inside the case and lowered to the ground from the scaffolding.

#2 RUBBINGS

Once back at our workshop the leaded glass panels are removed from the sash, secured on a large bench, and cinch wires cut flush. At this point two rubbings are made of each panel or section.

#3 DISASSEMBLY

One of the rubbings is now used as a guide for disassembly. The glass pieces are now taken from the old lead came, piece-by-piece, and placed on top of the rubbing. The original lead came is sized and sampled...then recycled.

#4 CLEANING

After complete disassembly each piece of glass is fully cleaned piece-by-piece and placed back in its place on the rubbing.

#5 GLASS SEAMING / REPLACING

This is one of the most critical points in any restoration!

1. Seaming is sometimes a very viable option, depending on the circumstances, where the original glass is cracked in a manner that a 'seam' won't detract from the original artists intent. A 'seam' is done by removing a tiny bit of glass, or grozing, to allow room for the heart of a piece of lead came, thereby making a lead joint where none previously existed. This method tends to work well on geometric borders, etc.
   
   
2. Many types of glass manufactured during the heydays of American stained glass (1880-1930) is still being made today and in many cases an exact match can be found. For European and Gothic windows constructed of 'full antique' (mouth-blown) glass we turn to our suppliers/importers as a few of the same companies that supplied glass to French, English and German studios in the 17th century, are still producing the same glass today!
   
   
3. Many restorations can be completed from our inventory of old windows that we purchase at auctions specifically to take apart and catalog the glass for future repairs.
   
   
4. When all other options have failed and a restoration requires a very unique or special textured glass we are able to have the glass custom made by a glass maker. This isn't as expensive as it sounds!!
   

WE WILL NOT ENGAGE IN ANY 'EDGE-GLUING' as glass and glue expand and contract at different rates and practices like gluing are among the many 'modern ways' that I consider NON-TRADITIONAL.

#6 PAINTING

Many ecclesiastical stained glass windows have vitreous painting - a face, hands, feet, and robes are always painted. This is an ancient process known as "Vitreous Painting" as the material used in the process is metal oxides mixed in a liquid base, applied and fired at temperatures between 1100 F to 1220 F. Many restoration projects do require the replacement of painted pieces and yes, sometimes a 'seam' is an acceptable alternative, but only in very minor instances. A cracked arm can be a good spot for a 'seam', but a cracked face needs replacing, period!!!

#7 REASSEMBLY

At this point the stained glass window is reconstructed, piece by piece - using the second rubbing as a 'glazing drawing', using Hi-Alloy Restoration Grade lead came of the same size and profile as the original lead. The use of hi-alloy came is the only 'technology' we utilize as most of the lead came used in the old days was made from mostly pure lead, which is very soft and weak. Today's newer cames are manufactured from a mixture of Lead, Tin, Bismuth and Antimony. This formula is not really new, but new in the U.S. and by using only hi-alloy lead came we can feel confident that the restored stained glass will outlast the original!! Once fully releaded the lead joints are now soldered on both sides and cleaned. Next to the cement bench...

#8 WEATHERPROOFING CEMENT

We use only 'traditional mix' cement that we mix ourselves. Weatherproofing cement, like the stained glass/glazier trade itself, has a history that goes back 1,000 years and we strive to continue this tradition in a purist belief and practice. We have several recipes for 'traditional cement' but the most basic one is usually an exact match to the original that most stained glass studios used in the U.S. during the late 19th century and for hundreds of years in Europe. We use no glazing compound as a base, as this will surely cause more damage in the future!!, nor will we use any of these new water based cements, either.

BASIC CEMENT RECIPE

20 lbs. Whiting

10 lbs. Plaster of Paris

½ tsp. Lamp Black powder

2 qt. Raw Linseed Oil

1 pt. Turpentine

adjust Turpentine less for thickness

The weatherproofing cement is applied by using a hard natural bristle brush and pushing the mixture under the leaf of the came by brushing in opposing directions until the leaf is 'full'. Once complete the excess is removed by brushing with whiting, fine sawdust, or plaster of paris and then the last bit of excess is removed with a sharpened dowel. The cemented panel is allowed to sit on the bench overnight with a fine layer of powder to absorb any 'oozing'. This process is repeated on the other side and then both sides are brushed to their original sheen with a fine bristle brush.

#9 ReBARS and CINCH WIRES

Round bars are inspected and if undamaged they are sanded, primed with oil base primer, and painted their original black color. They are reinstalled in the sash and new copper cinch wires are soldered to the panel. Panels with flat bars, steel sash, aluminum sash, and glazed into masonry are treated with equal professionalism to preserve their historical integrity.

#10 REINSTALLATION

The completed panel or panels are then reinstalled in their sash with a bedding compound and the cinch wires tightened to the bars and twisted/folded and excess trimmed. Wooden sash installations have the panels installed in the wooden sash with newly made, but historically exact, sash nails. The panel now is finished with a modern, oil based glazing compound.

This is a simplistic description of a generic restoration process. Every stained glass window is unique and this process will differ accordingly. Every sash installation is different - wood, steel, aluminum, masonry - and the history of the stained glass window and the studio that designed and constructed the window will make a huge difference in the restoration process. Most of the windows designed /constructed by Henry Keck Studios, Lamb Studios, John LaFarge, or Tiffany Studios / Tiffany Glass and Decorating Co. are glazed in several layers of glass, or Plated to 2, 3, 4, or 5 layers of glass- requiring a much more elaborate restoration process that would fill several volumes!! The descriptions outlined above are 'the simplest basics' that are written solely to allow a potential client/clergy to understand these 'basics'.

Those who work in the glaziers trade and wish to enter the Foundation's Apprenticeship Program CLICK HERE.

Those who work in the trade and wish to learn a few 'creative' restoration techniques - CLICK HERE to Find out about my next book!

top of page | © 2003 Historical Restorations Foundation