At Mural Unveiling, Ohavi Zedek Synagogue, August 2, 2015:

Lost Shul Mural Conservation Treatment: What’s Next?

“My name is Rick Kerschner, and I am Conservator Emeritus at Shelburne Museum where I directed conservation efforts for over three decades. I am coordinating the mural conservation efforts, providing technical expertise on moving plaster wall murals, and ensuring that the project director and engineers understand the more arcane conservation aspects of this project.

Constance Silver, an award-winning mural painting conservator who is treating the mural, is also with us this evening. Constance has over 30 years of experience treating wall murals ranging from murals in the US Capital Building to earthquake-damaged frescoes in Italy, and rare kiva frescos in New Mexico.

Two other conservation experts supporting the mural project who are not with us today are Professor Norman Weiss, of the Columbia University Historic Preservation Program, a world-renowned conservation scientist who developed and implemented a novel treatment to strengthen and secure the mural’s weak plaster, and Susan Buck, a conservation scientist with an international reputation in the laboratory analysis of paint cross-sections and pigments.

I also want to recognize Ray O’Connor who is here, the master carpenter who expertly planned, supervised and preformed all the hands-on carpentry work to remove the mural from Hyde Street and install it here above us. I stand in awe of Ray’s skills and ingenuity without which we would not be viewing this mural.

Many of you are familiar with the extensive conservation and engineering work that has been required to bring the Lost Shul Mural a few long blocks to this location. None of this could have happened without your support and we thank you.

Turning our attention to the mural, first, I will explain the present condition of the mural and then I will outline the work required to complete its conservation and restoration.

Let’s focus on the areas of the mural where the design is still obscured (points out fiberglass and CDD facing). In order to protect the paint and plaster from damage during the move, two facings were applied to the front of the mural. The facing immediately on top of the paint consists of silk crepeline that is adhered to the paint with a reversible varnish. It holds the recently reattached paint in place and protected it from being detached during the move. However, that facing alone was not strong enough to hold the plaster together had it detached from the lath wall. That required a stronger facing of fiberglass mesh adhered with a wax-like material called Cyclododecane. This second facing was not only very strong, but the Cyclododecane is a unique material that over time sublimes, changes directly from a solid to a gas, when exposed to air. Using Cyclododecane allowed a safe and easy removal of the facing after the move. We just waited for it to disappear and then peeled off the fiberglass mesh. To completely disappear requires about 4 months, but after 3 months enough had sublimed to allow safe removal of most of the fiberglass mesh just this past Wednesday.

Those of you who saw the mural during the move may recall that it was completely covered with sheets of plywood that held two inches of soft foam firmly against the painted plaster surface. These foam cushions and two facings were all precautionary measures to protect the painted plaster from damage from vibration or shock during removal, transport, and installation in this new location. Such protective aspects of conservation treatment are seldom revealed or explained to the public who usually see mainly the dramatic before and after treatment photos, but little of the messy stuff in between.

Nearly all of the rest of the mural is still covered with the silk crepeline facing that will be removed in late August after all the last remnants of the wax have disappeared. However, there is one area, the top section of the right panel, where just a few weeks ago Constance Silver removed not only the silk facing, but also several layers of discolored varnish and dirt, exposing bright original paint colors that probably have not been viewed in 70 years.

So where do we stand with the conservation and restoration of the Lost Shul Mural?
Four major treatment steps remain:

(1) The silk facing, discolored varnish and dirt must be cleaned from the rest of the mural. It is a tricky and delicate process to remove these varnish and dirt layers without removing any original paint. Constance will use cleaning procedures she has tested and perfected during many months of work on the mural.

(2) Additional tests and analysis are required to determine what may be overpaint applied by someone other than the original artist to improve the appearance of the mural. As varnish aged and darkened, contrasts between light and dark areas of the mural decreased and areas were repainted to try to restore such contrasts and improve the overall appearance of the mural. Nearly all murals are overpainted to some degree during their lifetime, some much more extensively than this one. We estimate that about 15% of this mural has been overpainted. As the discolored varnishes are cleaned and the original colors revealed, the overpaint also needs to be removed to reveal the original artist’s composition and colors beneath, and to re-establish the balance in the original composition.

(3) All areas of loss must be filled level with the original paint surface.

(4) The filled areas must be inpainted to visually blend them with the original colors and design. To differentiate between inpainting and overpainting, inpainting is confined to areas of loss of original paint. None of the artists design is covered. This is a difficult and exacting process where modern, reversible paint colors are visually matched to the surrounding original colors. Missing design areas, such as the letters in the left side of the Ten Commandments, can also be restored. Overpainting is repainting selected areas or even the entire mural. Overpainting is easier, faster, and often less expensive that inpainting which is often how it was justified, but it obscures rather than restores the original and seldom approaches the quality of the original artist’s work.

These four steps will require the efforts of several conservators and probably take more than 6 months of continuous work. Your support of this final third of this conservation project to stabilize, move, and restore this amazing relic of our cultural heritage would be greatly appreciated. We cannot do it without you. Constance Silver is available in the reception hall to answer any questions you may have about the conservation of the mural.”

— Richard Kerschner