Tag Archives: Artifacts

What’s In a Collection?
A Brief History of Saw Setting

Saw Wrest
Figure 1 Nineteenth Century Saw-Wrest

Being an historian, or in my case a collections manager, does not make you all knowing about history. There are times when you will look at an item in your collections and say “What could that possibly be?”

This was the case a few weeks ago while working on a complete inventory of the museum’s collection.

In one of our tool collections we came across a small, unlabeled, metal piece that had small notches on either side. Ideas were thrown out “it could be a gauge,” “it might go with a saw,” or “maybe it’s for electrical wires” however without being a hundred percent sure we decided to do some digging. Through our research we discovered that it was a saw-wrest, modern versions are referred to as saw-sets. Continue reading

Update on the Sea Service Pistol

Over the last month, I have been working on the flintlock pistol (previously discussed here).

After separating the other artifacts, I removed some of the concretion from the pistol itself. I did not want to take too much off or get too close to the surface of any artifact materials. Instead, we took the pistol back to get additional x-rays and see if there were any hidden surprises.

Taking new x-rays of the pistol.
Taking new x-rays of the pistol.
Two x-rays stitched together showing entire pistol.
Two x-rays stitched together showing entire pistol.

There did not appear to be any new findings or anything unexpected in the images. However, none of the lock, the firing mechanism or the barrel show up in the x-ray.

The first step in cleaning the pistol was removing the concretion off the brass fittings. I started working on the metal sections because I could clearly see them in the x-rays and they served as reference points for the rest of the gun. It is also much easier to air scribe off metal and I could use the edges of the brass to determine the condition of the wood. Continue reading

What’s in a Collection? U.S. Coast Guard Pin

Each month, we will be showcasing a different piece from our Museum collection. Outside of the artifacts on exhibition at the Lighthouse, we have hundreds of other historic pieces that are preserved in our collection.  

This small pin is a U.S. Coast Guard (USCG) collar/hat pin.

uscgpin

The pin is a screw version as opposed to a clasp version made of brass.  The design has the USCG emblem and is consistent with pins that were worn during WWII.  This particular one is missing the back portion that would have kept it secure on the uniform more about this later in the story. Continue reading

Hammering out another artifact

Andrew AirscribingAs we do conservation of artifacts from the Storm Wreck, we try to identify and work on pieces that are either unique or may have some identification or information pertaining to the ship. Some of the items that have gone through or are currently undergoing conservation include a 4-pound cannon, a 9-pound carronade, dozens of cannonballs, numerous cast iron cauldrons, pewter plates, spoons and thousands of nails.

These artifacts were all chosen because they had the potential to have some diagnostic numbers or maker marks on them. They were also chosen because they were easily identifiable while excavating and X-raying. One common theme uniting all of these artifacts is that they are all big solid pieces or clumps of hundreds of little bits of metal.

Unfortunately, in maritime wrecks most of the surviving material is going to be metal. This makes conservation easier, since the same processes can be used for almost all the different metallic objects.

However, it is a nice break and a challenge when we come across organic materials.

Artifact 12S 200 was excavated during the 2012 LAMP field school. At first, it did not look like much.

Artifact 12S 200 after excavation.
Artifact 12S 200 after excavation.

It appeared to be a standard concretion of shell and sediment over a few different objects. But, when X-rayed, the unremarkable blob turned out to be very interesting. Continue reading

18th Century Cannon Conservation – The Next Step

On Wednesday, October 7, 2015, we will begin the final phase of conservation for the two large cannons from the Storm wreck.
Removing concretion
Removing concretion

Lighthouse archaeologists excavated the guns in June, 2011, and brought them to the lighthouse. In the first phase of conservation, as much of the exterior concretion as possible was removed using hammers, chisels and air-scribes. This was to ensure no other artifacts were stuck inside the concretion, and if there were any, that they would be treated and conserved separately. It was also necessary to remove the extraneous material to speed up the second phase.

When the cannons were cleaned off, they were placed in metal tanks to undergo electrolytic reduction (ER). In ER, the gun is submerged in a solution of reverse osmosis water and sodium carbonate. Sheets of expanded steel mesh were placed on the sides of the cannon and connected to a positive electrical anode. The cannon itself is connected to the negative anode.

The "long gun" cannon in its electrolysis tank
The “long gun” cannon in its electrolysis tank during a regular break for cleaning

By drawing the electrical charge into the gun, we can very gradually and safely extract the salt (built up over 230 years in a marine environment) out of the cast iron and into the solution. The solution is periodically replaced and refilled so that, over the months and years, the chloride content of the cannons is reduced to as low as possible. This is the main concern for conserving marine artifacts. If the salt is not removed, the material will continue to corrode and break apart from the inside out.

After nearly four years of ER treatment, the cannons are now ready to come out and move to the third phase.

The 4-pound long gun will be the first to be removed. We will drain the solution, lift the cannon out of its current tank with our engine hoist and gantry and be wheeled over to our secured conservation facility for safety precautions. The cannon will then be lifted and placed into a new metal tank and submerged in reverse osmosis water. The water and gun will be heated for an extended period of time to rinse the artifact. This will open the pores of the cast iron and help remove any final unwanted soluble salts and any extra sodium carbonate solution. The rinsing should take one to two weeks with occasional water bath changes. We will take samples of the water to ensure as much salt is removed as possible before the final sealing phase.

Andrew Thomson is the Assistant Conservator for the St. Augustine Lighthouse & Museum. He received his graduate degree and training from the Conservation Research Laboratory at Texas A&M.