Laser training for our monumental projects team

Our department has owned a Compact Phoenix Nd:YAG laser for several years now and we have successfully used it to clean objects like this trio of birds for our Middle East Galleries. While there are a lot of possible applications, we have found the laser to be especially effective for cleaning stone objects with coatings, stains, and surface grime that are not easily removed using other tried and true cleaning methods including solvents, steam, and gels.

Did somebody say “stone objects with coatings, stains, and surface grime”? Because we have tons of those (literally) in our Conservation Lab Annex (CLA) where we are working on monumental projects for the Ancient Egypt and Nubia Galleries. But the last time we held a laser training session was before we hired our CLA team. Lasers are not found in all conservation labs, so it is not unusual for experienced conservators to have little to no experience with lasers.

A small Egyptian limestone stela mid-treatment. Many cleaning tests were carried out on this piece with very little success in removing some of the grime and stains. It is a good candidate for some laser cleaning tests.

In order to ensure a safe set-up and to get everyone trained on the equipment, we brought in Philadelphia-based conservator Adam Jenkins to provide the team with a full day of training. Adam specializes in laser cleaning and also conducted our last training session at the Museum in 2017.

Adam demonstrating use of the laser

After a classroom session covering the fundamentals and science of lasers, and the necessary safety protocols and PPE, we moved to the lab to try the laser on a few objects. We had success with several, which is very promising! The team is now set up to continue laser testing and cleaning on their own. We are grateful to Adam for his expertise and support and for this professional development opportunity. We are excited to incorporate this tool into the work out at CLA!

CLA conservation technician Kyle Norris testing the laser on an Egyptian stela

The right tools for the (monumental) job

Greetings from the Penn Museum’s Conservation Lab Annex (CLA)! You may remember from our first post the scale (large!) and types of objects we are going to be working on over the next few years. We are mostly working on architectural elements like doorways, windows, and columns that were part of the palace complex of the Pharaoh Merenptah, who ruled Egypt from Memphis from 1213–1203 BC. To put things in perspective, the doorway we are currently working on is over 12 ft tall and many of its fragments weigh hundreds of pounds. That means we have had to add a few new tools that are not typically found in a museum’s conservation lab. Most recently we’ve started utilizing a lot of new tools including a forklift, a gantry, and large-scale sandboxes.  

  • Forklift – A few weeks ago, the whole Ancient Egypt and Nubia Galleries Team attended a certification workshop in forklift operation. The certification course taught us the basics in how to safely operate our electric forklift. Having our own forklift onsite allows us to easily move some of the large stone fragments in and out of the lab, reorganize the layout of the warehouse to create space for rigging and lifting, and organize all of the Merenptah Palace pieces into one area.   
Egyptian Section Curator Dr. Jennifer Wegner smoothly maneuvering the forklift during our training session.
  • Gantry – At CLA we have a gantry crane in the warehouse which allows us to rig and lift some of the heaviest objects and fragments. This is especially important when we are trying to dry-fit pieces together before making more permanent joins. There are lots of different ways to rig or strap a fragment for lifting, but we’ve found that using shorter straps with a choke hitch is the safest way to lift our artifacts. In the photo below you can see that’s exactly what we’ve done. Once we have the straps secured and fully supporting the object, we begin to slowly lift, making sure the straps settle and don’t slip or re-adjust, dropping the object.  
CLA team using the gantry to lift part of the lintel from Doorway 1.
  • Sandbox – Sandboxes are often used in conservation to support objects during joining. Using a sandbox, we can place an object inside at whatever angle we need to in order to support the object on top with nothing but the weight of gravity. At CLA, our objects are quite large, so we are using old shipping crates and converting them into large sandboxes to accommodate our needs. In the photos below you can see the process of moving a fragment into the sandbox and then in the second photo you can see that fragment has been placed in such a way that it can now support the weight of the second, joining fragment on top of it. The blue tape serves as a guide to help us know exactly how the two pieces fit together once we have applied the adhesive and are ready to do the final joining. 
CLA team moving part of the lintel from Doorway 1 into a sandbox.
Fragments of Doorway 1 lintel being dry-fit together in the sandbox prior to joining.
  • Dremel – Lastly, and on a much smaller scale, we’ve been using a few different power tools. The most helpful so far has been the Dremel. While the Dremel is not a completely foreign tool to many conservators, it is most often used for making mounts or sanding fills and/or cross-sections. In this case we are using the Dremel to cut and remove all restoration pins that have become heavily corroded over the years, expanded, and are causing damage to the stone.   
Corroded ferrous pins from a previous restoration being cut and removed from Doorway 1 fragments.

As with any job, having the right tools is really important, for success and safety! We look forward to continuing to share the progress we’ve made on this project from our home offices, as we continue to work from home.

Cross-Campus Conservation Collaboration!

by Adrienne Gendron

Professional conservators generally specialize by material type. All the conservators at the Penn Museum specialize in objects, which includes a wide variety of materials from stone and ceramics to leather and wood. However, occasionally materials come across our desks that fall outside our areas of expertise. The Penn Museum recently acquired twelve Indian paintings on paper which need to be hinged so they can be safely handled by researchers. Because paper is a separate sub-specialty of conservation, we called on our friends at the Steven Miller Conservation Lab at the Penn Libraries’ Kislak Center for Special Collections, Rare Books and Manuscripts to help us with this task. This is not the first time we have taken advantage of our book and paper conservation colleagues right here on campus – follow this link to read about a recent treatment carried out in their labs on a parchment scroll.

In the case of the hinging project, our Penn Libraries conservation colleagues came to us – a couple weeks ago, Elizabeth McDermott, Tessa Gadomski, and Sarah Reidell visited our lab to provide a workshop on how to properly hinge paper objects for display.

Penn Museum conservators and interns listening to Liz and Tessa give instruction.

Hinging is a process in which small strips of paper are carefully adhered to the back of a work of art on paper in order to secure it within a window mat. It results in a strong and secure housing solution that ensures the safety of the object for storage and display.

One of the twelve works on paper that needs to be hinged (2017-22-13).

The most common and secure method of hinging is called a T hinge, which is composed of two strips of Japanese tissue paper. First, a strip of paper is carefully cut to size and a small amount of reversible adhesive is applied. Then, the strip is applied to the back of the top edge of the work and allowed to dry under weights.

The first strips in place along the top edge of a sample object.

Next, the work is flipped face-up and positioned on its backing mat. This is the trickiest part of the process, as the work must be perfectly positioned so that when the window mat is closed, it appears centered. Then, a second strip is adhered over the first strip and onto the backing board to secure the work in place.

The second strips applied over the first strips and onto the backing board, securing the work in place.

Because conservation is a small field, people often call on colleagues to for advice when it comes to different areas of expertise. We’re excited to apply our new skill to the twelve Indian paintings to ensure their long-term safety and preservation. Hinging can be a tricky business, but after our workshop we’re up for the challenge!

The first Indian work on paper we successfully hinged using techniques from the workshop (2017-22-20). When executed properly, hinges can allow a work to be flipped up so the back can be viewed.

Beaded Necklaces: Restringing to Secure the Past

By Tessa Young

Who doesn’t love a beaded necklace?  They’re sold commonly today, but did you know that they were popular in the Ancient Middle East? There are a number of fabulous pieces of beaded jewelry on display in the new Middle East Galleries, and several beaded items from our collection will be featured in the Museum’s Jewelry of Ur lecture and workshop scheduled for June 14th!

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Excavation of a Bronze Age necklace from a burial in the UK (Credit: Suffolk County Council Archaeological Service Contracting Team and Persimmon Homes Ltd [Anglia]) (https://www.futurity.org/shells-necklace-bronze-age-718992/)

When beaded artifacts are unearthed during excavation, typically the floss, or string, which held the beads has disintegrated in the burial environment. To ensure that the beadwork does not lose its original design, archaeologists will document their findings both photographically and through written records, and sometimes, they will string the beads onto a new piece of floss. This floss was usually good enough to get the pieces back to the museum, but it is not up to our modern conservation standards!

B15918 before treatment, with a broken strand and hasty repair tying off the ends

Here at the Penn Museum, when beadwork is destined for loans, display, or requires handling for programming, the Conservation Department wants to be sure that these objects are secure. For the upcoming Jewelry of Ur program, fellow conservation technician Alyssa Rina and I were tasked with restringing several pieces of beaded jewelry, including B15918, pictured above. The floss on this piece was previously broken and then tied off in a quick repair. The plan for this conservation treatment was to restring the beads in a loop with a more durable floss.

Depending on the piece, we restring using two different weights of braided nylon floss, which has the strength necessary to hold the beads securely while also being capable of holding knots. Monofilament (fishing line) is another popular choice, but we have found that knots can come undone rather easily with this material.

Restringing beads in a padded box using a needle in the artifact lab

Penn Museum Conservators have developed several tactics to keep the beads in place during the restringing process. First, we always keep the beads contained within a padded box, preventing the beads from rolling away and getting lost. Second, as seen in the photograph, we typically use a small clamp to secure the floss to the edge of the box. This keeps everything from shifting and rolling around. Finally, we thread the floss onto a small needle to aid in the efficiency of stringing the beads. These beads had large and regular enough holes to use a standard sewing needle, but thin, flexible beading needles are also an option.

Conservators also want to be sure that the stringing will remain in place. The first bead on the string is tied into place with two half-hitches (more-or-less a fancy double knot), and then the rest of the beads are strung into place with the help of a thin, flexible needle. If the beadwork is supposed to be a loop, at the end of the strand, the floss is threaded back through the first bead, and again tied off with two half-hitches. If the beadwork is supposed to be linear, the terminal bead is tied off with two half-hitches, making sure that the beads are tight but comfortable on the strand. Once this is done, the beads are stable enough to be handled or put on display without any fear!

B15918 after re-stringing

Conservation (training) in action

Our new curriculum intern, Marci Jefcoat Burton, was here for only couple weeks before we seemingly threw her to the wolves. That is, we asked her to work in the Artifact Lab and handle the open window sessions.

Marci describes her work to 2 visitors during an open window session

But we knew that Marci would do a stellar job working in front of the public and answering their questions. Although Marci is technically an intern, she already has extensive experience in conservation. In fact, as a curriculum intern, this is her final year of her graduate studies in conservation (she will complete her MA at the UCLA/Getty Master’s Program in the Conservation of Archaeological and Ethnographic Materials in June 2018).

One does not get to this point in their conservation training without a lot of experience working in conservation labs – to even be considered for an interview at many of the graduate programs, prospective students must have completed hundreds of hours interning with a conservator. More information about the path to becoming a conservator can be found here on the AIC website.

Marci is working on a number of projects here at the Museum, at least one of which she is basing in the Artifact Lab.

Marci working on a mosaic column drum from Al’Ubaid, Iraq (left) and examining an Islamic bowl at the microscope (right).

Stay tuned to the blog for more information about the column drum (in image above), and visit the Artifact Lab during open window hours for a chance to speak with Marci about her work!