Conservation of brass/bronze bookends

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    • #132023

      We’ve gotten a pair of brass or bronze bookends that were commissioned to represent the original logo of an important game company. These materials don’t come up often in a videogame museum, so I’d appreciate some help figuring out how to handle them. I’ve put a photo here: https://www.flickr.com/photos/digitalgamemuseum/13982416001

      I don’t want to damage any patination, but the surface is pretty covered with what I surmise are greasy fingerprints. What’s a safe way to clean these and then store them? Thanks!

    • #132028

      Degreasing with a low toxicity solvent such as acetone will help remove both grease and some salts from the fingerprints. Cotton wool can be abrasive and scratchy so use cotton wool swabs gently, in small circular movements, to wipe the surface clean with the solvent. A clean microfiber cloth may also help remove grease.

      In the UK we might clean light corrosion off with a paste called Prelim http://www.picreator.co.uk/articles/4_pre_lim_surface_clea.htm which does not disturb patina, if used with care.

      After cleaning, make sure the items are only handled by people wearing polythene or nitrile gloves in future. Store them in a dry environment if possible.
      Hope this helps.

    • #132027

      Helena, thanks. Since most of our collection is plastic, acetone is the last thing I would have described as “low toxicity solvent!” But I have some,, of course. I’ve found Pre-lim on Amazon.com and will be ordering that. Do you recommend a final coat of Renaissance Wax? I will vigorously enforce the gloves rule for these. Your expertise is much appreciated. Now, if you need to store CDs safely, I can help with that. 😉

    • #132026

      Dear Judith
      I think the question of coating or protection depends a lot on what will happen to the items and the importance attached to their appearance. If they are being kept in a dry storage container and it was vital that the metal surface can be seen with no distortion of its shine or color, if it was a sculpture for example, and the artist had expressed a view about not coating it, then all the effort would be put into keeping the conditions below 18% relative humidity to prevent further corrosion.
      If they were archaeological items and at risk of further corrosion, they would probably be stabilised by immersion overnight in a 3% solution (weight/volume) of benzotriazole in industrial methylated spirits (now called industrial denatured alcohol), allowed to dry (putting them in a dry box for this to remove any traces of moisture from the alcohol is an excellent idea) and then given 3 coats of a 5% solution (weight/vol) Paraloid (Acryloid) B72 in acetone to protect them. Care must be taken not to touch the surface with anything that could scratch it after taking them out of the benzotriazole as the protective layer formed is only a molecule or so thick. Once coated the copper alloy will survive in even less than ideal conditions, although the glove rule and keeping it as dry as possible are both good practice.

      Coating with Renaissance wax is a halfway house between the two treatments – it does provide some protection from accidental handling with bare hands and from humidity, but not as much as benzotriazole and Paraloid. It will make it more difficult to apply any other treatment later as the wax will have to be thoroughly removed before other treatments can be applied.

      Yes, please advice on storing CDs would be very welcome! Should we start a new post for that?

    • #132025

      Helena, thanks! I was able to find Pre-Lim on Amazon (at half the price the archival supply houses have it for!) so I’ll pick that up. I think we’ll stick them in Intercept bags with a warning about bare hands attached. The information about wax was very helpful – seems silly to apply something that might pose removal problems in the future.
      As for CDs, I’ll be happy to write something up. I don’t know if there’s general interest here – if not, I’ll just email you something. What do you think?

    • #132024

      Judith- the CD storage information would be would be great. More and more archives and museums are being told of the importance of digitization and backing up the digitized files. The primary method used by many smaller organizations are CDs. This would also be helpful to those of us who are now receiving/ or have received digital born archival materials (emails, word files, excel, digital photographs etc.) from donors on CDS.

      PS I love what your museum is doing.

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