Oaktoberfest (Sort of…) and a Toast

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MNMS-2002-001-469BD35 BT1
Gary with his hard-earned trophy.

A few years ago, one of our former conservators Elsa posted about the successful effort to disassemble the port gun carriage excavated from inside USS Monitor‘s gun turret. And last summer, Kate added a post about long-term efforts to stabilize the wooden internal components from the carriage.

One of my favorite pictures from the earlier posts shows former staff guru Gary hoisting an oak gun carriage side from the Wet Lab’s overhead crane for documentation and photography. Here it is in case you missed it:   Read more

Wood and metal meet science

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It generally goes without saying that we have a lot of metal artifacts to treat here at the Monitor Center. The term ‘ironclad’ does not exactly lend itself to images of wood or rope, but our collection of organic objects is not insubstantial. Thursdays have been devoted to survey of the organic objects in the walk-in refrigerator for the last couple of months, with a few breaks for other activities. This week we were doing something a little different, but still organic related. Some of you may recall that awhile ago one of the gun carriages was dissembled. The wooden sides still need to have their long iron bolts removed, an activity we hope to undertake soon, but for now those beautiful oak pieces are living in tanks with water, a corrosion inhibitor, and a biocide. The corrosion inhibitor helps to keep the iron bolts from corroding away until we can remove them, and the biocide prevents new ecosystems from growing in the lab. In addition to the corrosion inhibitor we are also using galvanic protection to prevent the iron bolts from corroding. The bolts are hooked up to magnesium blocks with electrical wire. Magnesium is less “noble” than iron in a galvanic series, which means that when it is connected to iron, magnesium will corrode faster than if it were unconnected. The other side of this is that the iron will corrode more slowly than if it were unconnected. So the magnesium will corrode into nothingness and the iron stays reasonably intact. The catch is that you periodically have to put in new magnesium blocks, an item we sometimes have difficultly tracking down. If anyone out there knows of a good source for magnesium blocks, please leave a comment or drop us an email.

So, as some of you may have gathered, Thursday was spent changing the solutions in these tanks and wiring in new magnesium blocks. Be sure to check back to the blog soon as we are testing dry ice blasting as a cleaning method this week. Hopefully there will be excellent results to share around this time next week.   Read more

Into the Condenser Tank – Week 1

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Last week got off to a great start as we drained the condenser tank for the first time in two years. This was the second draining of a tank since I arrived at The Mariners’ Museum and I was looking forward to getting back into one of the “big” tanks.

After draining, rinsing, and disassembling the anode rig, it was time for during treatment photographs and a brief condition assessment. The time in electrolysis has been good for the condenser; all of the iron surfaces are black with no active corrosion in sight. Taking the during treatment photos was a bit tricky seeing as we were maneuvering around inside of a steel tank that still had four inches of water in the bottom and a trench along one side.  First rule of using electronics in the tank: whatever you do, don’t drop the equipment. The pictures turned out really well, as you can see in the images below. Keep in mind that the entire assemblage in upside down.   Read more

Shifting Weight with the Engine

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This past week the 30,000 gallon tank containing Monitor’s steam engine was drained for a key milestone in the conservation of this unique artifact. The purpose for the tank drain was the installation of a new support system under the engine that will enable the eventual disassembly of  the object.  Up to this week, the engine which weighs approximately 25 tons, had been suspended off the ground from a massive I-bean supported on large steel posts. In the images below, you can see the engine before and after recent deconcretion efforts suspended from the I-beam.  

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Monitor’s Turret: A Private Screening

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This past week, the Monitor conservation staff began screening concretion and corrosion products removed from the interior of the turret over the last 10 weeks (see previous posts and video links on the main page). As with any archaeological excavation, we want to make sure that even small objects and fragments are recovered for future study and interpretation. This being said, we have opted to use a process called wet screening. Under this technique, material types of various sizes are separated out while at the same time washed by a steady stream of water to remove loose sediment and rust. The additional washing makes the identification of small artifacts easier and speeds up the overall screening process.   

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