NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Douglas Denny
Date: 2010 May 4, 09:26 -0700
Or, I'll silver it for you - so long as it is a 'one-off' - to get another dead sextant into good working order. (I do not want to be inundated with requests to silver mirrors).
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Silvering is quite easy so long as you have the materials and are careful with cleaning the glass surface. It is based on Brashear's method.(or Tollen's reagent - similar).
You need:- silver nitrate; conc.(0.88) ammonia solution; glucose; sodium hydroxide; de-ionised water.
and for cleaning: degreasing solvents: eg; carbon tetrachloride; methyl ethyl ketone; acetone; conc. nitric acid.
best if possible: finishing with conc. sulphuric acid and potassium dichromate solution.
I'll describe the method and concentrations of solutions if anyone requests it.
Douglas Denny.
Chichester. England.
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