What does a Welsh slate mine in World War II have to do with home antiques? More than many might think, according to museum collections expert Barbara Moore. Moore gave a talk at Boothbay Region Historical Society Oct. 17 on how to preserve historical collections, including in the museum and private homes. 

In 1939, the National Gallery in London faced grave threats from German bombings. The museum tried to protect its collections by dispersing them across the country, but it became clear they were at risk as bombings continued. Their solution was a disused slate mine in Whales.  

By 1941, the collection had been stored safely underground in the slate mine, kept in brick structures where environmental conditions could be controlled and made stable. After five years of sitting in the slate mine, Moore said the collections were in perfect condition. In fact, she said it was not until they returned to the National Gallery that some began to deteriorate.  

Moore said this was a textbook example of passive conservation: using stable, controlled conditions to keep collections safe. She was in Boothbay Harbor as part of a program to assess Boothbay Region Historical Society’s collection. She gave the talk for the public.

According to Moore, people with valuable art, antiques, or other historical items should first be aware of the conditions in their own homes during attempts to protect them. Moore said there are several factors that can cause damage including temperature, humidity, light and pests. She said for private collections or older homes, owners may have to work room by room.

She said a good place to start is to think about what art or sensitive items may be in basements and attics and move them to safer places where conditions can be stabilized.  

“Anything you want to preserve, even if it's your daughter's wedding dress, you don’t want to put it in the attic,” she said. “It's important to try to control conditions from the get-go.” 

Midcoast Maine is largely wet and humid, but the weather wildly fluctuates through the seasons. Moore said organic materials such as paper and textiles deteriorate when they get too hot. In high humidity, metals corrode and mold grows. However, if the humidity is too low, wood shrinks, adhesives fail and veneers lift. Ideally, she said to keep conditions stable. She recommended humidity be between 35% and the upper 60 percents, and temperatures be kept around 65F. 

According to Moore, sunlight can be especially harmful and the effects are often irreversible. Light can fade paint, leather and fabric. It even breaks apart the long fiber chains that hold together organic materials, such as paper and fabric. Moore said ultraviolet filters on glass or in shades can provide some protection. In addition, drapes or curtains can reduce light intensity, or limit the time the objects are exposed to it. She added that LED bulbs are the safest to use inside. 

Rodents and some insects can also cause damage. Rodents chew on paper and use it to make nests, silverfish eat the surface of certain items, and clothing months and carpet beetles can destroy fabrics. Moore said mitigation begins with monitoring for what pests may be present and acting accordingly. For example, silverfish like humid conditions so keeping the space dry may deter them. Fortunately, if an item has clothing moths or carpet beetles, freezing it for several days in a secure container will kill them, their eggs and larvae.  

Moore also discussed harm that can be avoided by proper storage. She said dust can leave a layer that scratches delicate objects when removed and pollutant gases can tarnish silver. To protect from these, she recommended enclosing certain items, such as model ships, in class containers. Moore also said cardboard and wood can emit acids that can cause damage. She said to use non-acidic materials to frame art or when storing items in boxes.  

Lastly, Moore talked about proper handling of items. The more an item is handled, the higher the chances of damage. In addition, oils on hands can leave marks or damage certain materials, especially metal. Moore said to wear gloves when handling artifacts and to keep them stored where they are well supported.