Dear readers. It's been a very long time since my last post.
Since graduating from West Dean, I am now a self-employed horological conservator in Seattle, Washington and have my own blog called The Automata Cabinet where I catalogue my many ventures in the world of horology.
Abby has asked me back to share with you the story of Kingslydale the automaton bear.
The bear was covered in its original rabbit fur and the delicate stitching that held the fur together was in perfect condition. I was worried about disturbing the stitching so I made arrangements to X-ray the bear at a local conservation studio. This way I would be able to see how best to access the mechanism without disrupting the fur.
The X-rays showed how the fur was attached to the mechanism. In the X-ray you can see small steel rivets holding the fur to wood supports at the base and at the top of the body.
Once the steel rivets were removed, I was able to see that the fur could be folded down allowing access to the mechanism without disrupting the stitching.
The mechanism turned out to be a very simple alarm clock mechanism that was altered to operate the motions of the bear. Once freed from the fur and base it was obvious what had caused the mechanism to stop.
The section at the end of the mainspring, which connects the spring to the inner barrel wall had broken, causing the spring to slip. The spring was annealed slightly at the end, allowing for a new hole to be made for the spring to catch on.
The fly had also broken. Every time the bear is stopped, the fly is engaged by the stop lever. Over time the force from the lever caused the solder join to weaken and it eventually broke.
A safety strip of brass was made and soldered into place.
I also found that as the fur and leather degraded, it was falling into the mechanism and gumming up the works. Fur was found wrapped around the pivots in the gear train.
I consulted with the books department on possible barrier layers that could be placed between the fur and the mechanism. Tyvek was suggested for its ability to protect without creating a microclimate inside the mechansim. A pattern was made using the original construction of the fur covering the bear.
One the Tyvek dress was cut out, it was then dyed to match the colour of the fur.
I tested different types of glues to apply the Tyvek and settled on gelatin. I made two strengths, and used them both in hot and cold applications to decide what would offer the properties needed for adhering the Tyvek. I needed something strong, yet removable that would not damage the original fur and wood surfaces.
From here I applied the dress with a 10% hot gelatin solution.
Once the dress was secured I folded the fur back up and reinserted the rivets. But before doing so, I soaked them in a tannic acid bath to remove and stabilise any rust. The rivets were then lightly coated in Renassaince Wax.
After replacing the rivets, I wrapped Kingslydale in Bondina and ace bandages to ensure that the gelatin adhered the Tyvek properly to the wooden surface and fur beneath... hence the photo you saw earlier this week.
Kingsydale now rings his bell and chomps triumphantly once again.