Here’s a simplified description of my process of making a pair of
eyeglasses from sheet metal. I’m not finished yet, but this shows at
least most of the arduous task:
I have made frames using this method with 925silver (sterling) and
900silver (coin?) in the past. The 900 alloy (90% Ag / 20% Cu) is I
believe a stronger material for spectacles which have fine eyewire.
However people like to know it’s a precious metal and “so, is it
sterling?” was the most common query about the 900sil frames. For
James’ frame (frame no 414) I’m using his mokume gane. Nine layers
of 925sil/shakudo, with the sterling layer on the inside.
I was intrigued when he approached me with the request that I make
him a mokume frame. I’d never worked with the material before, but
suspected that the layers of those two metals would have a superior
strength than plain solid 825sil.
Having worked on the frames this far I can report that it is indeed
tougher, and quite a joy to file. A little like brass is easier to
file than copper though it’s a harder metal, this mokume gane
machines well, not clogging the file. Which is great for this process
where so much filing is involved.
Why saw from sheet?
Accuracy is of prime importance when making eyeglasses. I also
construct eyeglasses from parts, fabricating by soldering, and that
method has its advantages, but accurately soldering fairly large
parts together is quite difficult for me. I devised tricks to help
with binding the parts in place, but is was all very stressful, and
if it went awry the joint was quite difficult to correct.
On the other hand the process whereby the whole frame is sawn from
solid sheet is one which I have taken a shine to over the last
several years. The accuracy is inherent in the computer printout, and
all I need to do is to file well. This method reduces the number of
joins to a bare minimum (hinges, nosepad brackets, rimlocks) and
produces a smooth looking transition from bridge to eyewire to
Something quite unobtainable by fabrication.
How I started with this method.
It was after I looked carefully at some early sterling eyeglass
frames at the museum of ophthalmology in San Francisco, back in 1991
(when James and I first met over coffee, I think), and looking at
those frames I noticed that they seemed not to be fabricated, seemed
to be sawn from solid sheet.
What jewellers did in 1760 was good enough for me.
By the way, I made my first frame (#1) in Sept 1981.