“So… why are you guys so salty about, well, salt?”

If you’ve been following along with the blog posts about conserving USSMonitor, you may have noticed a common theme: salt. Salt is bad forthis, we’re removing the salts from (or desalinating)that… but why? I’ve been sprinkling that stuff on my lunch; how bad can it really be?Read more

In my last treatmentpost, I wrote about the Myriopticon, an object that is far from the type of treatment that normally comes across a paper conservator’s bench. This time, I’m going to highlight an object that received a much more “typical” paper treatment while introducing a couple of common conservation techniques along the way. Keep reading for details on how I completed the treatment and for some satisfying before and after photos!

This print, titledFocht naer Nova Zemla in den Jaere MDXCVI(translating roughly to “Trip to Nova Zemla in the year 1596”) by Jan Luyken came to the lab for treatment due to its fragile condition. The piece was printed c. 1681 and depicts a scene from Willem Barents’ expedition to find a northeast passage from Western Europe to Eastern Asia. Barents made three separate voyages from Amsterdam spanning from 1594-1597. Ultimately the voyages were unsuccessful, with most of the crew members, including Barents himself, losing their lives on the third and final attempt. This print illustrates one of the many dangerous obstacles the crews faced on their journeys: walruses (yes, those are walruses).Read more

When the US Navy and NOAA archaeologists decided to recover the emblematicMonitorgun turret from the ocean floor, the entire engine room was in the way and therefore had to be recovered first. This included the main engine, ventilation engines, auxiliary pumps and the condenser. Now, in order to conserve these complex pieces of machinery, a large part of our job is to disassemble them. This allows for appropriate treatment of the different materials (iron, copper alloys and gaskets have different conservation requirements), while more exposed surfaces provide better extraction of harmful salts and thorough surface cleaning. Disassembly can be quite time consuming but there is no way around it! In 2019, one of the conservation team’s projects was to further disassemble the condenser (yes, parts had already been separated).

But first things first, what’s a condenser condensing and why?!

Condensers were invented in the late 18thcentury by a Scottish gentleman, James Watt, to make steam engines run more efficiently.Such engines used water properties to activate pistons. When steam (water in a gas form) located in a cylinder is quickly cooled and turned back to water (condensed), it takes up less space than in itsgaseous form which creates a vacuum in the chamber. As a result, the piston is first pushed in one direction before being pulled back in the other direction when a vacuum is created by cooling down the steam.Originally, in order to create this vacuum, water was sprayed directly on the steam within the piston chamber.It worked well but overall wasted a great deal of energy by repeatedly cooling and heating the cylinder.James Watt therefore saw the need for an external piece of equipment, a “condenser”, where steam would be condensed away from the piston chamber. The addition of this device rendered steam engines faster, more efficient, more reliable and more economical… And consequently condensers were used in different configurations in all marine condensing engines through the mid-19th century.Read more