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The "silvering" on infrared instruments is usually gold. It has the best reflectivity in the infrared spectrum, and has high resistance to oxidation and corrosion. Conversely, a thin gold coating is used to create optical filters which block infrared (by mirroring it back towards the source) while
305:
material requires the deposition of a thin layer of conductive but transparent material, such as carbon. This layer tends to reduce the adhesion between the metal and the substrate. Chemical deposition can result in better adhesion, directly or by pre-treatment of the surface.
201:
developed a process for depositing silver on the rear surface of a piece of glass; this technique gained wide acceptance after Liebig improved it in 1856. The process was further refined and made easier by the chemist Tony
Petitjean (1856). This reaction is a variation of the
703:
91:
is usually applied to protect the back side of the reflective surface . This arrangement protects the fragile reflective layer from corrosion, scratches, and other damage. However, the glass layer may absorb some of the light and cause distortions and
346:
The "silvering" on precision optical instruments such as telescopes is usually aluminum. Although aluminum also oxidizes quickly, the thin aluminum oxide (sapphire) layer is transparent, and so the high-reflectivity underlying aluminum stays visible.
115:", meaning that the reflective layer is on the surface towards the incoming light. The substrate normally provides only physical support, and need not be transparent. A hard, protective, transparent overcoat may be applied to prevent
326:
to improve the bonding between silver and glass. An activator is applied after the silver has been deposited to harden the tin and silver coatings. A layer of copper may be added for long-term durability.
330:
Silver would be ideal for telescope mirrors and other demanding optical applications, since it has the best initial front-surface reflectivity in the visible spectrum. However, it quickly
87:
Most common household mirrors are "back-silvered" or "second-surface", meaning that the light reaches the reflective layer after passing through the glass. A protective layer of
322:
The reflective layer on a second surface mirror such as a household mirror is often actual silver. A modern "wet" process for silver coating treats the glass with
358:
coils that can evaporate aluminum. In a vacuum, the hot aluminum atoms travel in straight lines. When they hit the surface of the mirror, they cool and stick.
791:
210:
solution is mixed with a sugar and sprayed onto the glass surface. The sugar is oxidized by silver(I), which is itself reduced to silver(0), i.e. elemental
172:
in the 15th century. The thin tinfoil used to silver mirrors was known as "tain". When glass mirrors first gained widespread usage in Europe during the
408:
253:
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The first tin-coated glass mirrors were produced by applying a tin-mercury amalgam to the glass and heating the piece to evaporate the mercury.
30:
This article is about the process of applying a metallic surface to glass. For the application of silver to a metal surface using mercury, see
225:
introduced the process of depositing an ultra-thin layer of silver on the front surface of a piece of glass, making the first optical-quality
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at the front surface, and multiple additional reflections on it, giving rise to "ghost images" (although some optical mirrors such as
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244:, led to most reflecting telescopes shifting to aluminum. Nevertheless, some modern telescopes use silver, such as the
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of the reflective layer and scratching of the metal. Front-coated mirrors achieve reflectivities of 90–95% when new.
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139:
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218:
290:(metallic glass), with no visible artifacts from grain boundaries. The most common methods in current use are
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765:"Ball Aerospace completes primary mirror and detector array assembly milestones for Kepler Mission"
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701:, Petitjean, Tony, "Silvering, Gilding, and Platinizing Glass", issued 1856-01-12
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Vacuum deposition can produce very uniform coating with very precisely controlled thickness.
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An aluminum vacuum-deposition process invented in 1930 by
Caltech physicist and astronomer
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To speed up the reaction process of the silver, the ornaments are shaken in hot water,
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35:
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792:"Advanced Large Area Deposition Technology for Astronomical and Space Applications"
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511:"Daily events and images of the installation of the BBSO New Solar Telescope"
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34:. For the use of electricity to apply metal coating to an object, see
592:"Historic mercury amalgam mirrors: History, safety, and preservation"
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622:
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237:. These techniques soon became standard for technical equipment.
38:. For the formation of metallic silver in photographic film, see
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79:, the term is used for the application of any reflective metal.
373:
or air in an oven so that it will form a tough, clear layer of
350:
In modern aluminum silvering, a sheet of glass is placed in a
181:
740:"Mirror, mirror: Keeping the Hale Telescope optically sharp"
541:"The Origins of Mirrors and their uses in the Ancient World"
625:[Regarding the products of oxidation of alcohols].
165:, but this was not done for the purpose of making mirrors.
771:. Ball Aerospace and Technologies Corp. 25 September 2007
669:[Regarding the silvering and gilding of glass].
286:
Silvering aims to produce a non-crystalline coating of
63:
process of coating a non-conductive substrate such as
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472:
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301:
Electroplating of a substrate of glass or other non-
153:. In the early 10th century, the Persian scientist
790:Fulton, L. Michael; Dummer, Richard S. (2011).
623:"Ueber die Producte der Oxydation des Alkohols"
145:had manufactured small glass mirrors backed by
40:Photographic printing § Silver mirroring
8:
749:. PF mag article 030805. Archived from
667:"Ueber Versilberung und Vergoldung von Glas"
338:to create a dark, low-reflectivity tarnish.
111:mirrors normally are "front-silvered" or "
590:de Chavez, Kathleen Payne (Spring 2010).
294:, chemical "wet process" deposition, and
409:List of telescope parts and construction
369:on the mirror; others expose it to pure
361:Some mirror makers evaporate a layer of
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858:
857:
846:
168:Tin-coated mirrors were first made in
135:used for re-coating telescope mirrors.
718:"Era of huge reflectors, page 2"
7:
882:, Diy mirror / mirroring / silvering
450:Construction Materials and Processes
252:mirror's silver was deposited using
229:glass mirrors, replacing the use of
447:Watson, Don Arthur (January 1986).
49:Silvering on the inside of a glass
545:L'Antiquaire & the Connoisseur
25:
802:(December): 43–47. Archived from
723:Space Telescope Science Institute
354:chamber with electrically heated
672:Annalen der Chemie und Pharmacie
214:, and deposited onto the glass.
157:described ways of silvering and
796:Vacuum & Coating Technology
727:. Amazing-space. Baltimore, MD.
453:. Gregg Division. McGraw-Hill.
1:
738:Destefani, Jim (March 2008).
176:, most were silvered with an
75:. While the metal is often
838:Episode 305 filmed at
479:Pulker, H.K. (1999-03-29).
922:
519:Big Bear Solar Observatory
263:
260:Modern silvering processes
29:
572:Oxford English Dictionary
463:– via Google Books.
219:Karl August von Steinheil
133:Mont MĂ©gantic Observatory
104:, take advantage of it).
685:10.1002/jlac.18560980112
649:10.1002/jlac.18350140202
334:and absorbs atmospheric
254:ion assisted evaporation
71:substance, to produce a
577:Oxford University Press
394:passing visible light.
278:
246:Kepler Space Telescope
136:
53:
273:
235:reflecting telescopes
130:
107:Therefore, precision
48:
131:Aluminising tank at
27:Silvering in mirrors
641:1835AnP...112..275L
94:optical aberrations
896:Chemical processes
745:Products Finishing
699:GB patent 1681
628:Annalen der Chemie
279:
137:
54:
856:External link in
539:Fioratti, Helen.
515:www.bbso.njit.edu
482:Coatings on Glass
424:Mercury silvering
404:Dielectric mirror
296:vacuum deposition
282:General processes
266:Vacuum deposition
208:diamminesilver(I)
206:for aldehydes. A
199:Justus von Liebig
32:mercury silvering
16:(Redirected from
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826:Episode 305
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599:Williamstown Art
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575:(1st ed.).
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547:. Archived from
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487:Elsevier Science
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324:tin(II) chloride
204:Tollens' reagent
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874:External links
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806:on 12 May 2013
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753:on 2009-10-11.
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709:
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679:(1): 132–139.
663:Liebig, Justus
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635:(2): 133–167.
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375:aluminum oxide
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292:electroplating
283:
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264:Main article:
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231:speculum metal
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36:electroplating
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849:cite AV media
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834:Anjou, Quebec
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830:How It's Made
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675:(in German).
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631:(in German).
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551:on 2011-02-03
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496:9780080525556
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460:9780070684768
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227:first surface
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223:LĂ©on Foucault
220:
217:In 1856-1857
215:
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161:in a book on
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859:|quote=
837:
825:
820:
808:. Retrieved
804:the original
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773:. Retrieved
769:spaceref.com
768:
759:
751:the original
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602:. Retrieved
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553:. Retrieved
549:the original
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522:. Retrieved
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174:16th century
167:
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56:
55:
725:(stsci.edu)
429:Metallizing
242:John Strong
233:mirrors in
890:Categories
836:, Canada.
604:2014-03-11
555:2009-08-14
435:References
303:conductive
149:, tin, or
98:refraction
69:reflective
880:Tions.net
524:6 January
140:Ptolemaic
117:oxidation
57:Silvering
51:test tube
747:Magazine
665:(1856).
621:(1835).
569:"tain".
517:(blog).
398:See also
367:beryllia
356:nichrome
342:Aluminum
332:oxidizes
191:In 1835
151:antimony
61:chemical
18:Silvered
901:Mirrors
810:6 April
775:6 April
637:Bibcode
579:. 1933.
276:Lauscha
196:chemist
186:mercury
178:amalgam
163:alchemy
159:gilding
155:al-Razi
123:History
109:optical
102:Mangins
96:due to
83:Process
67:with a
59:is the
906:Silver
705:
493:
457:
371:oxygen
363:quartz
352:vacuum
336:sulfur
318:Silver
313:Metals
250:Kepler
248:. The
212:silver
193:German
170:Europe
77:silver
73:mirror
595:(PDF)
143:Egypt
89:paint
65:glass
864:help
812:2013
800:2011
777:2013
526:2020
491:ISBN
455:ISBN
389:Gold
221:and
184:and
147:lead
681:doi
645:doi
381:Tin
365:or
182:tin
180:of
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851:}}
847:{{
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