And we’re back

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Elsa and Kate cleaning away.
Elsa and Kate cleaning away.

So we’ve had a rather long period of radio silence here on the blog. We’re going to try to prevent that in the future! There have been some changes in the lab. Dave, after over a decade with the Monitor, has gone off to chase a new dream with the Naval History and Heritage Command. We wish him all the best, but he is greatly missed here. We’ve added some new faces, too. Lesley joined us a new assistant conservator in December; she’s a recent graduate out of the University of Cardiff conservation program. Some of our long-time readers will remember Elsa. I am happy to say that she rejoined the team at the beginning of January. We’re thrilled to have her back.

Elsa and I have been getting to spend some time with an old friend of hers. Yes, we are once again working away at the wooden gun carriage sides. We’ve talked about these before – a couple of times. We’ve been doing mechanical cleaning of the sides and edges in preparation for chemical cleaning, which will remove most of the iron staining.   Read more

Wooden Gun Carriage Sides

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Newly constructed stainless steel mesh anode waiting to be installed.
Newly constructed stainless steel mesh anode waiting to be installed.

Some of you may remember that in the fall we spent some time doing maintenance on the wooden gun carriage sides from the disassembled gun carriage. Last week while Will was away at the annual AIC conference, Mike and I changed the solutions in these tanks, installed an anode and wired the carriage sides so that the iron bolts still inside the wood would be protected by impressed current. This is the same method being used to protect the metal components on the still assembled gun carriage, which can be viewed via the wet lab web cam here.

Check back soon to see updates about ongoing work in the lab.   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