[78-L] Wax!

[Michael Biel]

Robert M. Bratcher Jr. wrote:
> Why was the wax blank so thick? Stability with an inch thickness 
> maybe? Did a thinner wax blank not hold up well or something?
>   

They shaved and reused them many, many times.  And yes, a thin wax disc 
is quite liable to crack.

But there was a thin type of wax disc that was developed by Western 
Electric first for their Wide Range Vertical Recording because a wax for 
a 16-inch disc was very, very heavy, but also because shaving brought 
out internal stresses which might cause lateral movement in the groove 
when processed.  Victor also started using it, and others might have 
also.  It is called the "flow coat" and is shown in the video about how 
World ETs are made with Rubinoff.  A metal disc was put on a hot plate 
and a wedge of wax is melted on it.  They were made about a half hour 
before recording, giving it time to cool down and solidify but not 
become cold.  In the Victor ledgers there is a WAX column.  If they used 
a flow coat it says "Flowed" but if they used a thick wax blank they put 
the number of the wax in the column.  Each wax was numbered and kept the 
number every time it was shaved and reused.  There are also notations in 
that column for lacquers and optical film. 

Mike Biel  mbiel at mbiel.com