The authoritative public forum
  for Metal Finishing since 1989
-----

Speculum Plating

2000

I recently read about "Speculum Plating" in a very old edition of the The Canning Handbook [on eBay, Amazon, AbeBooks affil links] .

The plating is described as an electro-deposited hard silvery white alloy of tin and copper containing approximately 45% tin. The book says that it may be deposited directly upon steel, tin plate, copper, brass, nickel-silver and most other common metals and alloys. There was no additional information available.

I would like to know if this plating practice is still continuing and if so could anyone tell me from where I can obtain the know-how and information on the technique? Alternatively, is there a new substitute now available to this old process?

Aloke Mookerjee
- New Delhi, India

Dear Aloke,

Speculum was an old firm name for a copper tin bath, I do not think it is used any more. If you look for something similar try Miralloy from Degussa.

Regards Marcus

Marcus Hahn
- Sachseln,Switzerland
2000

---

Dear Aloke,

Miralloy might come close to speculum plating. White and yellow bronzes are plated with this type of bathes. White Miralloy is used in large scale on zip fasteners as substitution for nickel. Yellow Miralloy substitutes nickel as intermediate layer underneath gold coatings. In the European community, nickel is banned from objects of use, because of nickel allergy.

Jan Schmalhorst
- Schwaebisch Gmuend / Germany
2000

---

December 30, 2009

Dear alok,
next week I am taking my first trial of "SPECULUM" bath.
wish you "HAPPY NEW YEAR "

Shekhar Deo
- Pune/Maharashtra/India

I have an UK kerosene heater with a speculum reflector. I am amazed at how well the it works to reflect the IR from the heat source. Is there a replacement plating that has a high IR reflectance (that I can afford)?

Alan Yelvington
- Russell, Pennsylvania
November 29, 2011