Last Updated: Dec 01, 2016     Views: 25

Thank you for contacting us. I have contacted our Conservation Department here at the Museum and wanted to pass along their answer: 

"For cleaning glass we generally recommend washing with a mild detergent (something with no dyes or scents) and warm water. Followed by rinsing in de-ionized or distilled water to rinse off any minerals that are found in tap water. I think in this case it might be helpful to use a brush, cotton swab, or even a bamboo skewer to mechanically remove some of the material in the bore holes. I’m not sure about any chemicals that would specifically remove the brass and iron oxides. [The conservator] suggests poultices (basically cotton balls) soaked in 20% formic acid for the copper (brass) staining/deposits and soaked in 10% oxalic acid for the iron staining/deposits. They should be left on for about 10 to 20 minutes and rinsed well with de-ionized or distilled water (or it could be done before washing them as I described yesterday). Neither of these should affect the glass or any wires that may still be attached (the wires may end up a little shinier because some of the surface corrosion will be removed)."

Reply:

We used orange juice. The oxides in all those
thousands of holes were COMLPETELY dissolved and
washed away with tap water. This approach took only
6 hours to turn something on the order of #2 gravel into
brilliant, clear ice. ALL surface residue was also released.
Most sincere thanks for your kind attention. Please pass
on the nutritious solution to your conservators.