Fellow Shadow Watchers,
I need to achieve a durable(ish) dull brown
surface on a large dial plate of phosphor bronze (PB102) BUT without the
application of the heat involved in my usual process. For a start the
plate is simply too large and, most important, I can't risk distortion
due to local stress relief as the hour lines are very deep cut. Ideally a
brush-on or spray-on solution would be most convenient.
There's nothing useful in my 'bible' on patination (Huges & Rowe) so
I've been experimenting with possibilities such as spray-on oven cleaner
(caustic soda?) which is promising but blotchy. The best colour appears
where the 'rim' of a bubble is in contact with the metal which I suppose
is where air is excluded?
I'd be very grateful for any suggestions from anyone who has experience
in this field as I'm certainly no chemist.
With thanks in anticipation
Tony Moss
