John,
Your posting has perfect timing for my SGS project. Given that my 40 square
plain glass window is already in place in a second floor bathroom, I will be
creating the stained glass sundial as a framed piece to then be screwed in
place on the outside of the window. I like the magnetic
On 04/01/2011 15:50, Larry Bohlayer / Celestial Products wrote:
John,
Your posting has perfect timing for my SGS project. Given that my 40
square plain glass window is already in place in a second floor
bathroom, I will be creating the stained glass sundial as a framed
piece to then be
Larry;
Seven years ago I made some pourable color samples which
have been out in direct sunlight and weather since.
I used automotive fiberglass resin and added color to that.
Today they are as bright as day one.
My colors are solid but they also have translucent pigments
that I didn't try.
Good idea Tony!
I have a few of these little magnets that I bought at Ace Hardware. They
are round, 1 inch in diameter and 1/8 inch thick. Two of them work very
well together through a standard piece of glass that is 1/8 thick. I'm
sure you can find larger disk magnets- square ones too.
p.s.
I just had a thought.
Since you can buy magnets that are the same thickness as standard stained
glass (1/8), you could actually place a magnet into the design of a leaded
stained glass window dial. It would be surrounded by soldered lead came,
just as if it were a piece of glass in
a source for very strong magnets is a harddisk
that you don't use anymore. Get it open, next to
the coil that moves the arms are on each side a
very strong magnet. In this way an old harddisk is still usefull.
They are rather flat so you can use it the way John described.
Thibaud
At 19:44
John,
As you adventure to ever more powerful magnets, I would like to share my magnet
experiences with you. I have used the ultra powerful Neodymium magnets in my
work in determining the exit times of military high speed cannon projectiles
for several years now.
I have enough blood
Roderick, Why not to use a teflon ring with an inner disk of rubber. This will protect the rubber from the weather and still avoid the gnomon to slip. BR,
Ricardo Cernic
São Paulo - Brazil
http://relogiosdesol.blogspot.com
Em 04/01/2011 18:04, R Wall maill...@virginbroadband.com.au
The magnets may rust, but Galvanic Corrosion may also be a problem.
http://corrosion-doctors.org/Forms-galvanic/galvanic-corrosion.htm
Roderick Wall.
From: John Carmichael
Sent: Wednesday, January 05, 2011 7:22 AM
To: 'R Wall' ; 'Sundial List'
Subject: RE: Glass on Glass Mosaic Indoor Sundial
A teflon ring may help, but the rubber will still perish. I suppose it depends
on what you specify the life cycle is for your Sundial.
Roderick Wall.
From: Ricardo Cernic
Sent: Wednesday, January 05, 2011 7:47 AM
To: sund...@rrz.uni-koeln.de
Subject: Re: Glass on Glass Mosaic Indoor Sundial
Another thought…
Magnetic gnomons would be great for table-top analemmatic sundials too since a
moveable gnomon is required. You could have a steel strip on the dateline and
a magnet on the base of the vertical gnomon rod.
From: sundial-boun...@uni-koeln.de
Dear All,
A collegue pointed his iPhone at the
partially-eclipsed sun yesterday morning
and sent me the result:
http://www.cl.cam.ac.uk/users/fhk1/Eclipse11.jpg
It is clear that the camera wasn't stopped
down anything like enough but why, he asks,
does he get a pin-hole artifact of the
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