[SEL] Westinghouse DC generator..connecting leads to carbon brushes

[MaytagTwin at aol.com]

Hi George, 
 
I have been reading an old text which I keep in the throne room  library, and 
ran across a method of connecting copper pigtail wires to  carbon brushes.  
This is rather long and roundabout, and it comes from  The WAR-TIME GUIDE BOOK  
   prepared by the  Editorial Staff of POPULAR SCIENCE MONTHLY, GROSSET & 
DUNLAP, New York,  1942, p.147, but it looks like it will get you the brushes you 
may  need.
 
Copper Amalgam
Although mercury will amalgamate with copper sheet to produce a bright  
slivery surface, this method cannot be used to produce an amalgam of copper  
because the copper is only alloyed on the surface.  However, finely divided  copper 
metal, such as that obtained by precipitation, can be alloyed readily  with 
mercury to produce a pliable copper amalgam.  To produce the copper in  finely 
divided form, suspend several strips of zinc or iron in a solution of  copper 
sulphate or copper nitrate.  The iron or zinc will dissolve,  precipitating the 
copper out upon its surface in the form of a fine  powder.  Collect this 
powder, and if the solution is still blue, further  powder may be precipitated out 
by allowing more iron or zinc to act on the  solution.  Wash the precipitated 
copper well with running water and pour  onto it a solution of mercuric 
nitrate which can be made by dissolving a globule  of mercury in nitric acid.  
Allow the mercury chloride solution to act for  about ten minutes, until the color 
has changed somewhat.  Pour onto  the precipitated copper contained in a 
mortar several times its weight of  mercury metal and knead the mass under hot 
water by means of a pestle.  The  mercury will then amalgamate with the copper.
 
The produce can be used to take impressions, fill holes in copper work, or  
serve as an electrical conductive cement to join pigtails to carbon brushes, 
and  also to join certain metals together.  For this latter operation, the  
metals, which must have been cleaned, are heated to about 180°F., the copper  
amalgam rubbed on at the contact surface and pressed firmly together, reheating  
slightly, applying clamps, and allowing them to remain on until the metal joint 
 has become cold.
 
George, thank you for providing a reason to share.
 
Regards,
Ron Carroll
Clearmont, Missouri, USA