Church Window Restoration

It is Sunday morning. A young boy stares off into space. Glimmers of deep mysterious light penetrate his soul through his mind's eye. Ancient images mysteriously form, uplifting his awareness with a sense of past,present and the hereafter. Thoughts of heaven and hell mix with flashes of divine inspiration. His flights of fantasy focus on the stained glass window of young Christ before the rabbis in the temple. Wise, wordily rabbis with generations of wisdom oozing from their pores,are amazed by Jesus' question and answers. God's son is manifest as man on Earth. The questioning rabbis sit facing divine as wisdom,perfect love is reflected in the young Christ's eyes.

The response of these aged learned rabbis,the wisest generations of ancient Israel were able to produce, grows from amazement to awe. God's son, fresh innocence,eternal love, bliss manifest as Christ on Earth at this blessed time and place. This august assembly,the summation of generations of ancient culture,bears witness to the ultimate opportunity. A few years from now a choice will have to be made. Men, women, children,families and nations, must decide light or darkness.

The boy sits in the cold hard pew on this Sunday morning,as light passes through richly colored stained glass painted with the images of men and God's young son. Yet the art is not the glass,it is the light passing through the glass into the eyes,heart and soul of this boy on a Sunday morning. Again as in the time immemorial, the seed of faith is planted. Will the ground be fertile or barren? The span of a lifetime will tell. Hope springs eternal as the love of God shines again on Earth as the drops of individual love trickle into the ocean of God's love. This is the same opportunity witnessed by the wise sages, as they looked into the eyes of God, through his son. To be or not to be. The choice to Be, the choice of eternal life, is the choice awakening this young boy with fresh eyes and an open heart as he sits staring into heavens with the light of the ancient art of stained glass filling his heart,mind and soul. The preacher continues with Sunday service, enlightening the young boy's soul as he sits on the edge of his cold hard pew on a snowy winter Sunday morning, as a single spark ignites the kindling of a dry sermon.

Many of us have similar recollections of our youthful association with stained glass windows. We need to preserve our stained glass heritage for our children and their children's children. This is the stewardship of the contemporary church.

Preserving your stained glass windows can be divided into three groups: Routine Maintenance,Repairs and Restoration.

Maintenance includes cleaning. Special care needs to be taken when cleaning stained glass windows, especially painted stained glass. Ammonia based cleaners should NOT be used on stained glass as over time ammonia produces a negative reaction to lead came. Acid based cleaners,even including vinegar,should never be used on painted stained glass as these can damage the painted glass. Painted stained glass should always be tested for stability prior to cleaning. When in doubt,do not clean the painted areas of your stained glass windows. The damage to the painted areas of a stained glass window is non-reversible. A professional biodegradable pH neutral cleaner such as Triton X or Orvis horse shampoo which is readily available from your local tack shop works well and can be safely used to clean your stained glass windows once any glass painting has been tested for stability. The stained glass should be cleaned with a soft cotton cloth.

The perimeter putty that holds many stained glass windows into the sash and steel T-bar system needs to be replaced when it becomes loose. Stained glass window frames need to be painted,the perimeter re-caulked, and rotted section of wood or stone need to be replaced or stabilized with proper epoxy consolidation methods. The steel reinforcing systems in stained glass windows separate from the stained glass windows over time due to the expansion and contraction cycles. Periodically the steel reinforcing bars need to be examined and reattached where they have broken away from the stained glass windows. The steel reinforcing bars do not hold the window up.

That is the job of the steel T-bar and mullions and muntins. The steel reinforcing bars hold the stained glass in a flat vertical plane. Since the lead came is very soft, as long as the stained glass remains in a flat vertical plane it retains its stability.

Damaged or broken areas of stained glass windows need the appropriate repairs for the damage incurred. Broken panes need to be glued back together or replaced. Damaged areas may need to be replaced. Fire damaged stained glass windows need professional evaluation and a complex set of specifications for restoration, or may need to be replaced in part or in full.

Repair and maintenance of stained glass windows can include what some call stop gap measures which extend the life of your stained glass windows until the time they will need a full restoration. These procedures can be categorized as repairs and maintenance, or as restoration, and probably fit somewhere in between.

These measures include re cementing the stained glass window, replacing the loose or missing glazing cement that is packed between the flange of the lead came and the stained glass panes. The glazing cement both strengthens and weatherproofs the stained glass window. Flattening the bulges and deflected areas of stained glass that have sagged over time either from structural failure, expansion and contraction cycles, or due to a lack of stability in the original design of the stained glass window. Often the cause is multi-fold. Some bulging areas will required re leading; others can be flattened without re leading, depending on the design of the stained glass window and the severity of the bulging.

These and other techniques can extend the life of your stained glass window for a decade or two before a complete restoration is required. Full restoration involves re leading the stained glass window.

One serious problem for historic American stained glass windows is may were made with lead came that has a short life span of 70 to 100 years built into its life expectancy.

The stained glass windows of the great Gothic cathedrals were made with cast lead that contained impurities. Today we call some of those impurities alloys. During the industrial revolution, craftsmen learned how to make lead came from pure lead. Pure lead can be milled, forced between a set of rollers into shape with less labor than traditional casting methods. Milled pure lead came has stresses built into it from the day it is made. In many cases, this reduce its life expectancy to about 70 to 100 years. Today we have lead came available made with the best alloys and that are extruded (molten lead passed through a die). This gives the came more of the characteristics of cast lead as compared to milled lead came. We can guarantee the inclusion of the best alloys while excluding the impurities. Therefore, a new stained glass window or a re leaded stained glass window made with high quality lead came can be expected to last much longer than the stained glass window leaded up a century ago with milled lead. Caution should be used when purchasing a new stained glass window or when restoring your stained glass heritage that only the highest quality lead is used. Milled pure lead, mostly imported from Europe, made in the "old fashioned way", is still readily available and should be avoided.

When do my stained glass window need to be restored? One sure sign that your windows need to be restored are sagging and bulging panels of stained glass. By the time your windows bulge to the point that the stress from the deflection is cracking and breaking out panes of stained glass, you will probably agree your stained glass windows need restoration. Another sign is that your lead came is heavily oxidized, the equivalent of rust on steel. On lead, oxidation appears as a white powder coating your lead came. The oxidation along with broken and cracked surfaces on the lead came and broken solder joints holding the lead matrix together also show that your stained glass windows may be in need of restoration.

The stop gap methods of flattening the bulges, re leading the worst sections, re cementing, replacing missing steel reinforcing bars and adding additional reinforcing to weakened areas will buy you time,maybe 15 to 20 years, before you will have to restore(re lead) your stained glass windows. Eventually a full restoration will be required to preserve your stained glass heritage. Fifteen to 20 years is considered good for many building repairs. Properly designed and fabricated stained glass windows can have a life expectancy measured in centuries. How many building materials can make that claim?

When restoring your stained glass windows, you will want to correct any structural design defects that have become apparent with the test of time. One of the most common structural defects is over-sized panels. Some craftsmen of the past seem to have had a contest to see who could build the largest panel. A large stained glass window is made from many smaller panels of stained glass preferably of about 12 square feet or less in size divided by the window frames' mullions, muntins and T-bars.

Large over-sized panels are prone to failure. A simple correction to this problem is to divide the panel into two or more structurally sound panels. If this process will impact the artistry of an historically or artistically significant window, there are other techniques that can be used. For example, we can add additional reinforcing to the stained glass.

Unstable glass paint can be stabilized using modern consolidation techniques. Missing areas of paint can be replaced with reversible cold painting techniques or by painting the missing areas onto a new, thin, clear pane of glass and plating the new pane on top of the original pane to make it appears as originally intended in a non-invasive manner. Small areas of removable (reversible) cold painting can be added to areas such as small pock marks that tend to appear on otherwise stable areas of kiln-fired glass painting. A surprising number of historic stained glass window are painted with cold painting (regular oil paints). These surface are fragile and need to be treated with great care. All areas of painted glass in stained glass windows need to be carefully evaluated and tested prior to restoration, repair or maintenance. Properly formulated and kiln-fired traditional glass painting should remain stable for centuries. Some older stained glass windows were made from unstable paint formulas or were improperly fired in kilns without temperature controls or pyrometers to carefully control the kilns' temperature which are required to produce a long lasting stable painted glass surface.

With proper stewardship a stained glass window is one of the ecclesiastic arts that can last through the centuries to inspire our faith.