Hi Les:
I'm getting many good questions now, so many in fact that it would very
difficult to resrict their numbers so that they and their answers fit on
only one page. Too many good questions would be left out. But I do agree
with you about keeping it simple. That is why I think it is very
Hi Skipjack and Les:
I think that you're both half right! Les is correct that the FAQ questions
and answers should be basic and simple, and you are right that we should
have extensive coverage of all topics. At the moment, I am gathering ALL
questions, regardless of merit. We will decide
Tony,
Great stuff! Can you give any indication of how much currect is needed (per
square inch of object?).
Also, have you ever tried masking some areas of the film ( hour numbers)
before the dying process, so that they come out a contrasting (or clear)
colour?
Cheers,
John
I have (with help) uncovered a few bugs in my postscript dial programs;
* I (generally) mark only sunny hours in the northern hemisphere--I
apologize. I'll fix it.
* The capuchin dial was chopping off some of the curves for some lats.
It's fixed.
*The equatorial dial crashes if the mottos are
At the NASS conference we got into a discussion on who invented
trigonometry. I knew that the Greeks were great on geometry but thought
that trig functions and tables were a later development, from the early
Renaissance.
A quick web search on the question Who invented trigonometry? turned up
the
Can I just add a note of caution to Tony's note that concentrated caustic
soda is really nasty stuff as well
as the sulphuric acid. If you get a splash of conc caustic soda in your
eye, don't bother to rush to the tap - by the time you get there it will
have already gone !!!
Have fun but BE
Roger Baily contributed:
Great, informative note. I always wondered how these coloured oxide films
were created. Thanks, I will try your techniques.
Have you, or others on the list, had any experience using caustic to
chemically etch aluminum? We used to make hydrogen to fill party ballons
and
Warren Thom wrote:
I have looked around the web for more information and found a caution of:
Because of its porosity you do not get a satisfactory anodized finish on
cast aluminium which has been machined. An as-cast aluminium surface will
not have a lusterous finish when anodized. (looks
Hi Tony,
I have looked around the web for more information and found a caution of:
Because of its porosity you do not get a satisfactory anodized finish on cast
aluminium which has been machined. An as-cast aluminium surface will not have a
lusterous finish when anodized. (looks poor)
What
