Mercury Mirror Conservation
Conservation, decontamination and decommissioning of historic mercury amalgam mirrors.
For historic houses, museums and private collections. Call 0345 548 8586 or contact us to discuss your requirements.
History
Mercury amalgam mirrors
Originally invented in Venice in the 1400s, mercury amalgam mirrors were widely produced from the 16th century. The method remained in use until around 1900, when silver replaced it as the reflective coating.
Throughout those 500 years, the reflective finish was created by gliding glass over tinfoil flooded with a layer of liquid mercury. The mercury reacted with the tin to form a layer of tiny crystals, an alloy of mercury and tin. The voids between the crystals remain filled with a fluid phase containing approximately 0.5% tin in mercury.
The problem
What’s the problem with mercury?
Over time, corrosion from humidity in the air or from damp walls causes the crystals to grow larger and the mercury to slowly evaporate, leaving tiny voids between the back of the glass and the amalgam.
The fluid mercury migrates to the bottom of the mirror, and the corrosion produces tin oxides, releasing liquid mercury from its solid phase. While measured levels of mercury vapour are usually far below any official toxic limit, mirror frames can often contain beads of liquid mercury that can escape and need to be disposed of safely.
“We can safely remove, provide a full condition report along with treatment proposals, and carry out the required conservation or decommissioning by stripping the mercury surface, resilvering the original glass and replicating the distressed mercury.”
Paul Broomfield, Founder & Conservator
Our service
Specialist decontamination & decommissioning
Our workshops offer a specialist decontamination and decommissioning service, in accordance with health and safety guidelines, to help historic houses, museums and private collections comply with requirements to control substances hazardous to health. We remove any visible droplets, clean contaminated surfaces, dispose of the waste safely, and seal and line the junctions between the glass, frame and backboards.
Once in our care, we provide a full condition report with treatment proposals. On approval, we carry out the required conservation or decommissioning: stripping the mercury surface and resilvering the original glass with hand-poured silver, creating a similar level of distressing to echo the original mirror plate.
Our restoration services →Get in touch
Discuss your collection
Send us photographs and details of the mirror and we’ll advise on the best approach.
Contact us →