The Cleaning Begins

Looking out from the scaffolding over so many huge bones in need of intensive cleaning, conservation and restoration certainly seems like a monsterous task but we have to start somewhere so we have chosen to begin working on the whale hall's most famous skeleton the Right whale (Ubalaena glacialis) which has been hanging in the musuem window for the city to see for around 100 years.





We've named the skeleton 'Benny' and the cleaning has begun.




This first skeleton gives us the oppertunity to develop the techniques we will use for cleaning this fragile and very unique bone material. The skeletons continually ooze a thin layer of oil - this oil comes from the thick layer of blubber produced by the whales in life - and the dust and dirt sticks to this oily layer forming a tough and greasy black layer over the bones.




An example of the grease and dirt layers in this case covering tail vertebrae.

Marielle cleaning Benny's arm

After experimenting with various cleaning solutions and recipes we settled on using substances that would have a degreasing effect and remove the vast amjority of the dirt without ....... the excessive use of water (which can be absorbed by the bones), without damaging the structure of the bone (bleach for example would dregrade DNA) and that wouldn't leave any surfacantants on the bone surface.

Finally, it was decided that after much experimentation a combination of ammonia hydroxide, ethanol, acetone and detergent would be used. This has proved very effective as the photo of Benny's arm below shows....

A dramatic difference can be seen in the bone colour between the cleaned ulna (top) and uncleaned radius (bottom).

However, despite the fact that the whale oil is causing so many problems for our skeletons (and the team trying to clean it off) traditionally it has been a hugely important and widely traded product that was harvested particularyly from Right whales such as Benny. Whale oil has been used in a wide range of products from lipstick to margarine and it wasn't until the descovery of petroleum waxes and oils that it went out of use.