choice.
I made a large equatorial disk dial. At 30" diameter it was large enough to
have a steel core with brass around the outside in which the numbers and
minute ticks were engraved. Adjacent to this is matte white terrazzo. The
terrazzo shows even dim shadows. The brass has never been good for defining
shadows, neither new and shiny nor weathered.
When I made the dial, I blackened the engraved letters, numbers and time
ticks. When the dial was new, the contrast made the numbers easy to read.
As the dial aged, the contrast became less and although the engraving is
deep, there was no crisp contrast. Once while applying paste wax to the
brass, I noticed that the white in the letters was much easier to read than
the black and now I leave the white wax in the engraved spaces. Some day I
hope to figure out how to neatly fill the engraving with matte white epoxy.
It would have been easy during construction, but as is, it looks difficult.
I am so impressed with the white matte shadow definition and ease of reading
white letters and marks, that if I build new dials, big or small, I will
fill the letters with white, and supply a white filled ring near the time
ticks, at least 1/4" (6 mm) wide, so the gnomon's shadow can be clearly
seen.
People who ooh and ah over large shiny machined pieces of brass may not find
this composite as their ideal of perfection, but I see a functional beauty
that continues from shiny new through weathering.
Chuck Nafziger
Seattle Washington
47 deg 40.7' N
122 deg 23.7 W
>Toni: I see the gnomon being refelcted on the surface. My experience is in
>that case that it is rather difficult to read the shadow instead of the
>refelxion. I suggest to mat the surface slightly to increase the
readability.
>Thibaud
>
Agreed! This is the eternal problem of anyone making sundials for
'presentation' purposes. The client wants something that looks
'sparkling new' and certainly NOT the dull matt surface which is ideal
for shadow casting. I try to compromise with a 'brushed' finish using 600
grit abrasive. This yields a surface which produces a feint 'compromise'
shadow on a 'bright' surface for presentation, after which the natural
patination process will take place....and then there is gold plating on a
bead-blasted surface for a lovely golden 'eggshell' finish if funds
permit.
One thing I have never been able to fathom is WHY, if confronted with
polished brass, people feel an overpowering compulsion to finger it! :-(
.... :-)
You can't win!
Best Wishes
Tony
I have some JPEGs of Patrick, presentation dial in hand, but am something
loth to inflict them on the main List!...perhaps to my faithful JPEGGERS!
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