Today, I returned to work on the Parthian pot. The potsherds had been soaked in deionized water for 6 days. Each day, the salt concentration was measured and recorded, and the water was changed. By the last day, the salt concentration had plateaued. Using Unruh's equation for standardizing the conductivity measurements in desalination, κ (adj) = κL/g, where κ is the salt concentration in µS, I calculated that the potsherds stabilized at .7 µS. Getting below 2 µS for κ (adj) is preferable for ceramics. While still wet, the edges of the potsherds were brushed to gently clean them. It is imperative that the edges are clean when I join them.
After drying out, the edges of the potsherds had to be consolidated using Paraloid B-72. The 5% solution which I used has acetone as the solvent. This concentration was already made up, but 10% would have been better for my purposes. With a small paintbrush, I applied several layers of the solution onto the broken edges of the sherds. I used a fume hood during this process because of the acetone. At the end, the edges were slightly darker and felt a little like shiny plastic. Essentially, the fabric is porous and the dilute adhesive is drawn into the capillaries where it then dries and seals off the ceramic. I could actually see it being drawn in and bubbling slightly when air was displaced. This prevents further damage, such as from bad joins, jostling, crumbling, or water. Having this smooth sealant will also help when I piece the pot back together. The layer is thin enough that it will not get in the way of a close join, but will prevent the heavier adhesive from soaking in, which could potentially harm or discolor the ceramic fabric, and will make it easier to take apart and redo if I make a mistake or if it has to be fixed in the future. The consolidation was not necessary, and many conservators do not do this step, but at the Kelsey they feel it is useful.
Lastly, I worked on some condition reports. One of the faculty members is organizing a small display about the excavations at Antioch to be added to the permanent exhibition. The objects that she requested for display have to be checked and mounted by conservators before they can be installed. The pieces she requested included architectural fragments and archival material. For the archival material, Claudia used mylar strips to hold down some materials, and Japanese rice paper and wheat starch paste to mount others. The stone pieces I checked were all stable and did not require any additional treatment before being displayed, but the chunk of mosaic has a piece of mortar loose. In the picture below, it is a small piece below the yellow tessera on the left. Stone is fairly inert and does not require much conservation. However, that does not mean that they should not be monitored periodically. I documented this issue and took photographs today. Soon, I will stabilize the mosaic by consolidating the mortar.
After drying out, the edges of the potsherds had to be consolidated using Paraloid B-72. The 5% solution which I used has acetone as the solvent. This concentration was already made up, but 10% would have been better for my purposes. With a small paintbrush, I applied several layers of the solution onto the broken edges of the sherds. I used a fume hood during this process because of the acetone. At the end, the edges were slightly darker and felt a little like shiny plastic. Essentially, the fabric is porous and the dilute adhesive is drawn into the capillaries where it then dries and seals off the ceramic. I could actually see it being drawn in and bubbling slightly when air was displaced. This prevents further damage, such as from bad joins, jostling, crumbling, or water. Having this smooth sealant will also help when I piece the pot back together. The layer is thin enough that it will not get in the way of a close join, but will prevent the heavier adhesive from soaking in, which could potentially harm or discolor the ceramic fabric, and will make it easier to take apart and redo if I make a mistake or if it has to be fixed in the future. The consolidation was not necessary, and many conservators do not do this step, but at the Kelsey they feel it is useful.
Lastly, I worked on some condition reports. One of the faculty members is organizing a small display about the excavations at Antioch to be added to the permanent exhibition. The objects that she requested for display have to be checked and mounted by conservators before they can be installed. The pieces she requested included architectural fragments and archival material. For the archival material, Claudia used mylar strips to hold down some materials, and Japanese rice paper and wheat starch paste to mount others. The stone pieces I checked were all stable and did not require any additional treatment before being displayed, but the chunk of mosaic has a piece of mortar loose. In the picture below, it is a small piece below the yellow tessera on the left. Stone is fairly inert and does not require much conservation. However, that does not mean that they should not be monitored periodically. I documented this issue and took photographs today. Soon, I will stabilize the mosaic by consolidating the mortar.
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