I have had in an unusual piece,It was a white ceramic aviation circuit board.
One side was gold plated circuitry the reverse was completely plated(sample 5 in Pic a/)
The plating striped off for testing and was indeed Au (Pic b/)but there was a slight dark containment visible in the Stannious test.
I noted that there was still a bright silver plating left under the Au which did not look like it had reacted to any thing at all..It took two day's to digest even heated.
The second digestion's stannious test has given a gray/blue result??(pic c/)
I dropped the Au from the first solution and the percipitent is very dark almost black,the spent solution no longer give a reaction to stannous testing.
Any ideas??
One side was gold plated circuitry the reverse was completely plated(sample 5 in Pic a/)
The plating striped off for testing and was indeed Au (Pic b/)but there was a slight dark containment visible in the Stannious test.
I noted that there was still a bright silver plating left under the Au which did not look like it had reacted to any thing at all..It took two day's to digest even heated.
The second digestion's stannious test has given a gray/blue result??(pic c/)
I dropped the Au from the first solution and the percipitent is very dark almost black,the spent solution no longer give a reaction to stannous testing.
Any ideas??