By Elisabeth Boekhoven and Luci Cipera

The Canadian Museum of Nature closes its doors the week of January 7 to 11 for its annual cleaning blitz. This is a week wherein the museum’s employees work together to spruce up the galleries and other public spaces.

Cleaning the exhibits is a big part of this week, in addition to the many maintenance projects undertaken to refresh and revitalize the museum for our visitors. This is a week where we can take on bigger projects that take more than a few hours or a day.

The blue-whale (Balaenoptera musculus) skeleton in the gallery.
The mounted skeleton of a female blue whale (Balaenoptera musculus) is the centrepiece of the RBC Blue Water Gallery. Image: Russ Brooks © Canadian Museum of Nature

One such project is the cleaning of our biggest specimen, the blue whale (Balaenoptera musculus) skeleton, in the RBC Blue Water Gallery. This is no small task and planning is of utmost importance. We have to plan how best to reach all the parts of the whale using a lift and ladders so we can clean the whale without causing any damage.

A woman vacuums part of the blue-whale skeleton.
A conservation technician cleans the blue-whale skeleton during the 2012 cleaning blitz. It will be cleaned again this week. Image: © Canadian Museum of Nature

Dust does build up in the museum, just like in our homes. Regular cleaning does help keep the dust under control, but something as big as a whale can be done only once a year. So, armed with soft brushes, backpack vacuums and dust masks, we tackle a year’s worth of dust!

A woman cleans the blue-whale skeleton using a brush.
Our conservators use soft brushes to winkle dust from the small cracks in the whale bones. Image: © Canadian Museum of Nature

Another thing that makes cleaning the whales tricky is that whale bones tend to be quite oily. If you’ve visited the gallery then you might remember reading that whale bones can continue to leak oil long after the whale died.

View of the whale skull showing dark spots on the bones.
Dark areas of seeping oil are visible on the whale skull. Image: Marcie Kwindt © Canadian Museum of Nature

Before the whale even went on exhibit, the bones were cleaned and treated to remove as much oil as possible to minimize oil leakage. However, darker patches on the skeleton can be seen and are evidence of seeping oil. If they are left untreated, oil may even start to drip out of the bones!

The oil is sticky so the dust on these areas cannot be removed without removing the oil. Therefore, once a year during our blitz week, the whale gets a bit of a spa treatment to help remove the oil that has seeped out.

In order to remove the oil from the surface of the bones, house-cleaning-grade ammonia is used in the form of a poultice. The solution is created—basically ammonia and water. Then paper towel is soaked in the solution and applied to the bones. Plastic is then wrapped over the paper towel to keep it in place and help with the oil removal, as well as to cut down on the odour of the ammonia.

The whale skull, mostly wrapped in plastic.
The whale skull gets a “spa” treatment from ammonia poultices.
Some bones in the skeleton, wrapped in plastic.
The plastic holds the poultice in place on the bones. It also suppresses some of the ammonia smell. Image: Marcie Kwindt © Canadian Museum of Nature

Sometimes ingenious solutions of keeping the poultices in place are also used. Do you recognize this pool-size object being used here?

Once the surface oil is mostly removed, the poultices can be disposed of and the whale should be alright for at least another year!

A folded pool noodle applies pressure to the bones on either side.
Yes that is a pool noodle! It’s helping to gently keep the poultices in place while they work on the surface oil. Image: Marcie Kwindt © Canadian Museum of Nature