Saturday, August 2, 2014

An Iron Age Painted Sherd

While we work primarily with metals in the Kaman conservation lab, we had a particularly lovely painted sherd come through the other week. This sherd was excavated from an Iron Age level at Kaman Kalehöyuk and is typical of the painted ceramics from that period. It was found broken in two and the painted design was partially obscured by soil and surface concretions.

Conservation Intern Claire D'Izarny first cleaned off the soil using cotton swabs wetted with deionized water and then removed the concretions by scalpel. While cleaning the sherds, Claire decided to make use of our Dino-lite USB microscope to show what it is like to do this delicate work under the microscope.  

Here are photos taken with the Dino-lite showing a detail of the painted design before and after removing the concretions.

Now that the painted sherd has been cleaned and re-assembled, it can be drawn, photographed, and studied!

Friday, August 1, 2014

New X-Ray Machine for the Kaman Conservation Lab!

Some exciting new equipment arrived in the Kaman Conservation lab this year- a Faxitron digital cabinet X-ray machine! Thanks to the support of the Commemorative Organization of the Japan World Exposition ('70) and the Türkiye İş Bankası, which helped fund the purchase of this equipment, we can now x-ray a wide range of objects. This will be especially useful to investigate metal finds with thick corrosion and small block lifts prior to micro-excavation.

Our x-ray machine can fit objects up to approximately 15 x 18 x 18 inches; however, the digital sensor at the bottom of the cabinet is 9 x 11.5 inches, limiting what we can x-ray at any one time to that size. Since our unit has a digital x-ray sensor, we don’t have to use x-ray film or plates- which is the reason this type of radiography is called 'direct radiography'. Our Faxitron (model 43855) goes up to 130 kV, and is semi-automatic- meaning we control the camera/sensor from the computer but we have to set the kV and turn the x-ray source on and off directly on the Faxitron cabinet.

Our new protocol is to x-ray all of our small metal finds prior to treatment. This is incredibly useful as it allows us to better understand the shape and condition of an object when bulky corrosion is present, sometimes helping us to detect an original surface. X-ray imaging also aids in the decision-making for treatment, and assists the conservator in the investigative cleaning process. For example, prior to treating this copper alloy object, identified as a stamp, conservation intern Claire D’Izarny  took an x-ray with the new Faxitron. The design on the face of the stamp showed up clearly in the x-ray and helped Claire understand where to clean away the corrosion and burial soil obscuring the design.

While we love our new tool, we are still exploring the different applications for our machine. We hope to post any exciting finds and updates here and we would love to hear about other people’s experiences with similar machines! In the meantime, here are some more x-rays for your viewing pleasure...