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Detail of Great Chapel window by Louis Tiffany restored by Bovard Studio at Reid Memorial Presbyterian Church, Richmond, IN
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PRESERVING THE HERITAGE OF STAINED GLASS, BY RON BOVARD
REVELATIONS FROM A STAINED-GLASS MASTER
PRESERVING THE HERITAGE OF STAINED GLASS, BY RON BOVARD
from Church Business, January, 2001, Volume 6, Issue 1, pages 34-36.
With proper stewardship, a stained glass window is one of the ecclesiastic arts
that can last through the centuries to inspire faith.
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. 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 his eyes, heart and soul.
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.
Preservation of glass windows can be divided into three groups: routine
maintenance, repairs and restoration.
Routine maintenance
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; over time, ammonia produces a negative
reaction to lead. Acid-based cleaners-even vinegar-should never be used on
painted stained glass since they can damage it. 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 (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 sections
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 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 releaded. 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
stopgap 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.
Measures include re-cementing the stained glass window, replacing the loose or
missing glazing cement packed between the flanges 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 multifold. Some bulging areas will
require releading; others can be flattened without releading, 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 windows
for a decade or two before a complete restoration is required. Full restoration
involves releading the stained glass window.
One serious problem for historic American stained glass windows is that many
were made with lead came that has a short life span of 70 to 100 years. 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 sets 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 reduces its
life expectancy to about 70 to 100 years. Today, we have lead cames 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 releaded
stained glass window made with high-quality lead came can be expected to last
much longer than the stained glass windows leaded up to 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 the
"old-fashioned way," is still readily available and should be avoided.
Restoration
When do your stained glass windows need to be restored? One sure sign is
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 indicate your stained glass windows may need restoration.
The stop gap methods of flattening the bulges, releading the worst sections,
recementing, replacing missing steel reinforcing bars, and adding additional
reinforcing to weakened areas will buy you time, maybe 15 to 20 years, before
you have to restore (relead) your stained glass windows. Eventually, a full
restoration will be required. 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. Some
of the most common structural defects are oversized panels. Craftsmen of die
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 about 12 square feet or less in size, divided by the window frames'
mullions, muntins and T-bars. Large, oversized 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
historically or artistically significant windows, other techniques can be used.
For example, additional reinforcing can be added to the stained glass. Unstable
glass paint can be stabilized using modem 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 appear as originally
intended in a non-invasive manner. Small areas of removable (reversible) cold
painting can be added to areas such as small pockmarks that tend to appear on
otherwise stable areas of kiln-fired glass painting. A surprising number of
historic stained glass windows are painted with cold painting (regular oil
paints). These surfaces 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 of pyrometers to
carefully control the kilns' temperatures, both of which are required to
produce a long-lasting stable painted glass surface.
Ronald Bovard is the principal owner and CEO of Bovard Studio, Inc. Bovard also
wrote Windows For The Soul, published by Wardell Publications, and his studio's
work has been featured in numerous books, newspapers, magazines and television
shows, including three PBS features. Bovard personal art has been exhibited in
galleries and museums around the world
A careful examination of this photo of a restored Tiffany window reveals
extensive use of plating
BOOK REVIEW
REVELATIONS FROM A STAINED-GLASS MASTER
from Traditional Building, January/February, 2001, p. 176
Windows For The Soul by Ron Bovard Wardell Publications P.O. Box 480069, Fort
Lauderdale, FL 33348 Phone 954-958-9379; FAX 954-958-9380 160 pp.; softcover;
$27.95 ISBN 0-919985-32-7
E-mail: info@wardellpublications.com
Website: http://www.wardellpublications.com
Stained-glass artist Ron Bovard, Chairman and CEO of Bovard Studio, has
produced an inspirational book about his art, its craft, and the vision that
sustains it. Windows For The Soul documents the range of professional
challenges Bovard Studio has met over the years in which it has created and
restored religious-themed stained glass. The book's chapters include such
topics as the unique requirements of painting and staining glass; fabricating
and bracing stained-glass windows; providing protective glazing; cleaning and
maintenance; and the innovation of computer-aided-design (CAD) technology. A
special chapter documents the entire sequence of steps in the Studio's
restoration of an original Tiffany window. Numerous other case histories are
woven throughout the text as well. Bovard describes his work for churches
located around the country, from Hawaii to Kansas, Alabama to Michigan. Most
movingly, he relates how his studio created a panel for a terminally ill mother
from Texas, who commissioned a stained-glass window to be placed in her
mausoleum, depicting a guardian angel watching over her three beloved young
daughters. The combination of expert technical information with a keen sense of
both the human and the transcendental features of this craft is exceedingly
rare - and is one of the unique beauties of Windows For The Soul. Also
beautiful - and unique - is the book's wealth of illustrations: Over 350 color
photos exemplify every phase and aspect of this demanding art, from concept
drawings to the finished and installed window. These hundreds of pictures also
give some sense of the spectrum of artistic subjects and styles available
within the realm of ecclesiastical stained glass, as Bovard's expertise
embraces designs monumental and intimate, stylized and realistic, traditional
and contemporary. The book even includes examples of Bovard's art. 350 color
photos exemplify every phase and aspect of this demanding art, from concept
drawings to the finished and installed window. These hundreds of pictures also
give some sense of the spectrum of artistic subjects and styles available
within the realm of ecclesiastical stained glass, as Bovard's expertise
embraces designs monumental and intimate, stylized and realistic, traditional
and contemporary. The book even includes examples of Bovard's art which extend
beyond the traditional Christian applications: There are instances of secular
work - abstract designs ns, nature scenes - as well as stained-glass windows
for a Masonic Retirement Center and panels that depict Hindu deities. If you're
anxious to learn more about stained glass, either as a technique to be learned
or simply as an art form to be enjoyed, Windows For The Soul is an
indispensable volume.
This resurrection window was for the Santa Clara Mission Cemetery, San Jose,
Calif.
The restoration of a Tiffany window for St. Lukes, United Methodist Church in
Dubuque Iowa, involved replacing lost details, restoring structural integrity,
hand-packing the flanges of the came (inset), and cleaning and repairing dirty
and deteriorated parts of the window. Reinstallation of the massive panel was
the grand finale of the project.
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