260:
35:
117:
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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
294:
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.
190:
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
692:
80:
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
335:
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.
104:", 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
315:
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.
319:
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
76:
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
311:
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
347:
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.
780:
199:
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
161:
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
374:
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.
19:
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
214:
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
89:
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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687:
397:
868:
242:
529:
580:
728:
233:, 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.
279:(metallic glass), with no visible artifacts from grain boundaries. The most common methods in current use are
28:
143:
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121:
884:
507:
128:
560:
207:
852:
754:"Ball Aerospace completes primary mirror and detector array assembly milestones for Kepler Mission"
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837:
690:, Petitjean, Tony, "Silvering, Gilding, and Platinizing Glass", issued 1856-01-12
298:
Vacuum deposition can produce very uniform coating with very precisely controlled thickness.
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229:
An aluminum vacuum-deposition process invented in 1930 by
Caltech physicist and astronomer
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215:
101:
8:
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To speed up the reaction process of the silver, the ornaments are shaken in hot water,
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781:"Advanced Large Area Deposition Technology for Astronomical and Space Applications"
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500:"Daily events and images of the installation of the BBSO New Solar Telescope"
407:
90:
320:
291:
162:
57:
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34:
86:
23:. For the use of electricity to apply metal coating to an object, see
581:"Historic mercury amalgam mirrors: History, safety, and preservation"
105:
49:
39:
655:
611:
828:
344:
139:
116:
264:
226:. These techniques soon became standard for technical equipment.
184:
181:
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27:. For the formation of metallic silver in photographic film, see
68:, the term is used for the application of any reflective metal.
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or air in an oven so that it will form a tough, clear layer of
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351:
340:
200:
158:
97:
65:
61:
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In modern aluminum silvering, a sheet of glass is placed in a
131:
77:
53:
729:"Mirror, mirror: Keeping the Hale Telescope optically sharp"
530:"The Origins of Mirrors and their uses in the Ancient World"
614:[Regarding the products of oxidation of alcohols].
154:, but this was not done for the purpose of making mirrors.
135:
760:. Ball Aerospace and Technologies Corp. 25 September 2007
170:
658:[Regarding the silvering and gilding of glass].
275:
Silvering aims to produce a non-crystalline coating of
52:
process of coating a non-conductive substrate such as
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463:
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Electroplating of a substrate of glass or other non-
142:. In the early 10th century, the Persian scientist
772:
699:
456:
876:
807:
572:
557:
779:Fulton, L. Michael; Dummer, Richard S. (2011).
612:"Ueber die Producte der Oxydation des Alkohols"
134:had manufactured small glass mirrors backed by
720:
680:
492:
429:
248:
29:Photographic printing § Silver mirroring
778:
738:. PF mag article 030805. Archived from
656:"Ueber Versilberung und Vergoldung von Glas"
521:
327:to create a dark, low-reflectivity tarnish.
644:
600:
100:mirrors normally are "front-silvered" or "
726:
686:
579:de Chavez, Kathleen Payne (Spring 2010).
578:
283:, chemical "wet process" deposition, and
398:List of telescope parts and construction
358:on the mirror; others expose it to pure
350:Some mirror makers evaporate a layer of
258:
115:
33:
877:
650:
606:
467:
435:
157:Tin-coated mirrors were first made in
124:used for re-coating telescope mirrors.
707:"Era of huge reflectors, page 2"
871:, Diy mirror / mirroring / silvering
527:
439:Construction Materials and Processes
270:
241:mirror's silver was deposited using
218:glass mirrors, replacing the use of
436:Watson, Don Arthur (January 1986).
38:Silvering on the inside of a glass
13:
534:L'Antiquaire & the Connoisseur
14:
906:
862:
791:(December): 43–47. Archived from
712:Space Telescope Science Institute
343:chamber with electrically heated
661:Annalen der Chemie und Pharmacie
203:, and deposited onto the glass.
146:described ways of silvering and
785:Vacuum & Coating Technology
716:. Amazing-space. Baltimore, MD.
442:. Gregg Division. McGraw-Hill.
551:
1:
727:Destefani, Jim (March 2008).
423:
165:, most were silvered with an
64:. While the metal is often
7:
827:Episode 305 filmed at
468:Pulker, H.K. (1999-03-29).
386:
330:
10:
911:
508:Big Bear Solar Observatory
252:
249:Modern silvering processes
111:
71:
18:
561:Oxford English Dictionary
452:– via Google Books.
306:
301:
208:Karl August von Steinheil
122:Mont MĂ©gantic Observatory
93:, take advantage of it).
674:10.1002/jlac.18560980112
638:10.1002/jlac.18350140202
323:and absorbs atmospheric
243:ion assisted evaporation
60:substance, to produce a
566:Oxford University Press
383:passing visible light.
377:
369:
267:
235:Kepler Space Telescope
125:
42:
262:
224:reflecting telescopes
119:
96:Therefore, precision
37:
120:Aluminising tank at
16:Silvering in mirrors
630:1835AnP...112..275L
83:optical aberrations
885:Chemical processes
734:Products Finishing
688:GB patent 1681
617:Annalen der Chemie
268:
126:
43:
845:External link in
528:Fioratti, Helen.
504:www.bbso.njit.edu
471:Coatings on Glass
413:Mercury silvering
393:Dielectric mirror
285:vacuum deposition
271:General processes
255:Vacuum deposition
197:diamminesilver(I)
195:for aldehydes. A
188:Justus von Liebig
21:mercury silvering
902:
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815:Episode 305
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588:Williamstown Art
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564:(1st ed.).
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536:. Archived from
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519:
518:
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476:Elsevier Science
465:
454:
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313:tin(II) chloride
193:Tollens' reagent
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403:Optical coating
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277:amorphous metal
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32:
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12:
11:
5:
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863:External links
861:
859:
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795:on 12 May 2013
771:
745:
742:on 2009-10-11.
719:
698:
679:
668:(1): 132–139.
652:Liebig, Justus
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624:(2): 133–167.
608:Liebig, Justus
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364:aluminum oxide
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281:electroplating
272:
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253:Main article:
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220:speculum metal
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25:electroplating
15:
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867:
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839:
838:cite AV media
832:
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824:
823:Anjou, Quebec
820:
819:How It's Made
816:
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664:(in German).
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623:
620:(in German).
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540:on 2011-02-03
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485:9780080525556
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449:9780070684768
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408:Mercury glass
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216:first surface
213:
212:LĂ©on Foucault
209:
206:In 1856-1857
204:
202:
198:
194:
189:
186:
183:
178:
176:
172:
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155:
153:
150:in a book on
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102:first-surface
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814:
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797:. Retrieved
793:the original
788:
784:
774:
762:. Retrieved
758:spaceref.com
757:
748:
740:the original
732:
722:
710:
701:
682:
665:
659:
646:
621:
615:
602:
591:. Retrieved
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574:
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542:. Retrieved
538:the original
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511:. Retrieved
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381:
373:
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338:
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318:
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238:
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163:16th century
156:
127:
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45:
44:
714:(stsci.edu)
418:Metallizing
231:John Strong
222:mirrors in
879:Categories
825:, Canada.
593:2014-03-11
544:2009-08-14
424:References
292:conductive
138:, tin, or
87:refraction
58:reflective
869:Tions.net
513:6 January
129:Ptolemaic
106:oxidation
46:Silvering
40:test tube
736:Magazine
654:(1856).
610:(1835).
558:"tain".
506:(blog).
387:See also
356:beryllia
345:nichrome
331:Aluminum
321:oxidizes
180:In 1835
140:antimony
50:chemical
890:Mirrors
799:6 April
764:6 April
626:Bibcode
568:. 1933.
265:Lauscha
185:chemist
175:mercury
167:amalgam
152:alchemy
148:gilding
144:al-Razi
112:History
98:optical
91:Mangins
85:due to
72:Process
56:with a
48:is the
895:Silver
694:
482:
446:
360:oxygen
352:quartz
341:vacuum
325:sulfur
307:Silver
302:Metals
239:Kepler
237:. The
201:silver
182:German
159:Europe
66:silver
62:mirror
584:(PDF)
132:Egypt
78:paint
54:glass
853:help
801:2013
789:2011
766:2013
515:2020
480:ISBN
444:ISBN
378:Gold
210:and
173:and
136:lead
670:doi
634:doi
370:Tin
354:or
171:tin
169:of
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
