Interesting experiment in silver conservation...
Prometheus183
Posts: 385
Effect of Wavelength in the Laser Conservation of Silver Textile
Lasers in the Conservation of Artworks, LACONA IV, Paris, Frankrike
11-14 September 2001
Abstract
Laser removal of surface contaminants on silver textile was carried out using Nd:YAG laser radiation from near infrared (1064 nm) through visible (532 nm) to ultraviolet (266 nm) produced by frequency harmonic generation. A thread in the textile was made of silver and silk in which the silver ribbon wraps the bunch of silk fibres. The goal of this work is to find a feasibility to clean the tarnished silver without any damage of the underlying silk since the conventional chemical treatment is difficult to apply in this specific specimen. From the results, it was found that the laser wavelength of 266 nm is most appropriate to clean the silver surface without causing any damage both to the silver and the silk surfaces while 1064 nm wavelength easily provides the damages such as melting and burning to the silver as well as the silk inside.
Dang.. sounds expensive! Here's what I did with a common non-key date merc...
I took an aluminum pie pan (must be aluminum for the reaction to ocur), put one teaspoon of salt, one teaspoon of water softener, and filled it with near scalding water, agitated until desolved. Dipped the silver into the solution, making sure it touches the bottom of the pie pan (about 3 seconds). The softner and salt adhear to any contaminants instantly, and the electrallisis effect of touching the aluminum causes the solidified contaminants to expell from the silver, much like trying to place two like poles of magnets together.
Rinsing in denatured alcohol immediately after removed any impurities and evaporates nearly as fast as accetone. The result was a clean piece of silver without damage to the "silk", or in an example of a coin, the "mint luster".
I'll let this piece sit in a flip for 90 - 120 days or so and post my findings. I know dipping is a no-no, but I figure when it comes to my stomach lining, what would I rather drink, salt or accetone? Hmmmm.. tough call.
Craig
Lasers in the Conservation of Artworks, LACONA IV, Paris, Frankrike
11-14 September 2001
Abstract
Laser removal of surface contaminants on silver textile was carried out using Nd:YAG laser radiation from near infrared (1064 nm) through visible (532 nm) to ultraviolet (266 nm) produced by frequency harmonic generation. A thread in the textile was made of silver and silk in which the silver ribbon wraps the bunch of silk fibres. The goal of this work is to find a feasibility to clean the tarnished silver without any damage of the underlying silk since the conventional chemical treatment is difficult to apply in this specific specimen. From the results, it was found that the laser wavelength of 266 nm is most appropriate to clean the silver surface without causing any damage both to the silver and the silk surfaces while 1064 nm wavelength easily provides the damages such as melting and burning to the silver as well as the silk inside.
Dang.. sounds expensive! Here's what I did with a common non-key date merc...
I took an aluminum pie pan (must be aluminum for the reaction to ocur), put one teaspoon of salt, one teaspoon of water softener, and filled it with near scalding water, agitated until desolved. Dipped the silver into the solution, making sure it touches the bottom of the pie pan (about 3 seconds). The softner and salt adhear to any contaminants instantly, and the electrallisis effect of touching the aluminum causes the solidified contaminants to expell from the silver, much like trying to place two like poles of magnets together.
Rinsing in denatured alcohol immediately after removed any impurities and evaporates nearly as fast as accetone. The result was a clean piece of silver without damage to the "silk", or in an example of a coin, the "mint luster".
I'll let this piece sit in a flip for 90 - 120 days or so and post my findings. I know dipping is a no-no, but I figure when it comes to my stomach lining, what would I rather drink, salt or accetone? Hmmmm.. tough call.
Craig
The Rede we live by: If it harms none, do what you will.
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Byron
My first YOU SUCK on May 6 2005