Re: 100 meg resistors $2.00 ea

[Bernard Cleyet <anngeorg@PACBELL.NET>]

aquadag is a dag in water (colloidal suspension of carbon in water --
sometimes ascohol)  ceresin wax is a very high resistivity wax used to protect
surfaces from moisture -- used in electrometers etc.  glyp is a high
resistivity paint (GE original mfgr.) used to coat high V. fixtures, etc.  --
also high vacuum seal hence the expression "glyp and ship" (high vacuum items)

bc

GLYPTOL
       Phthalic anhydride [Pronounced Phallic] General Electric Co. Adheres
well to metals. used to seal quartz windows to metal or glass and to seal
small leaks. Do not heat above 150 C. Glyptol is
       the tool of ethically challenged glassworkers, too lazy to fix small
leaks. Glip it and Ship it! is their motto. <
http://www.plasma-art.com/goodbadsci.html
more: http://www.pupman.com/listarchives/1998/July/msg00149.html

AQUADAG:
http://www.macbicnj.com/glsblwequip/18820.htm

Amature use of ceresin:
http://www.pupman.com/listarchives/1996/may/msg00068.html


 EXCEERPT from:  file:///AmSci/AmSci01/tbLib/Electrometers/electrometers.html


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Electrometers and Electroscopes





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                                             Electrometers and Electroscopes

                                                      H.V. Neher




                   Insulators used in electrometer and electroscope work. The
insulator ordinarily used in
                   electrometers is amber. The amber now on the market is
usually a manufactured product which
                   has as good insulation properties as the natural amber and
has the advantage of being obtainable in
                   a variety of sizes. Amber has a high volume resistivity,
and the surface resistance of clean amber
                   is also high. If the surface is contaminated, the best
remedy is to remove some of the amber with a
                   clean tool by turning it in a lathe. If this is not
convenient, the amber may be covered with a thin
                   coat of ceresin, as will be described later.

                   The best insulator known is clean, dry, fused quartz. By
clean quartz is meant quartz which has
                   not touched anything since being heated to the softening
pQint, and by dry quartz is meant
                   quartz either in a good vacuum or in a gas dried by
phosphorus pentoxide. Fused quartz is also
                   superior to other insulators in that the soak-in is far
less. Under comparable conditions amber has
                   at least ten times the soak-in possessed by quartz.

                   Ceresin is a natural wax which has remarkable electrical
insulation properties.19 It is about the
                   same hardness as ordinary paraffin, each at 20 degrees C.
However, it has a somewhat higher
                   melting point than either paraffin or the artificial
ceresin, being liquid at 65 degrees C. Its
                   insulation properties have been measured by Curtiss20 of
the Bureau of Standards. He gives the
                   surface resistivity as greater than 101' ohm cm even at 90
per cent humidity. One of its main uses
                   in the laboratory is to~ improve the surface resistance of
other insulators. If the solid insulator
                   and the ceresin are each heated to around 100 degrees C.
and a light coating of ceresin applied, the
                   surface leakage will usually be found greatly reduced,
sometimes by a factor of 100.


                   19 Natural ceresin is distilled from the mineral ozokorite.
An artificial ceresin, which is inferior to
                   the natural product, is also on the market. In ordering,
the natural product should be specified.


Jon Greenberg wrote:

> Sorry, what are aquadag, ceresin wax, and glyptol? Never heard of them.
>
> > ----------
> > From:         Bernard Cleyet
> > Reply To:     phys-l@lists.nau.edu: Forum for Physics Educators
> > Sent:         Friday, January 18, 2002 2:06 AM
> > To:   PHYS-L@lists.nau.edu
> > Subject:      Re: 100 meg resistors $2.00 ea
> >
> > India ink is aquadag --  better on teflon or kelF, then spray with
> > glyptol.
> > (or paint with molten ceresin wax?)
> >
> > bc
> >
> >
> > William Beaty wrote:
> >
> > > On Thu, 17 Jan 2002, Greg G. wrote:
> > > > Well.....
> > > >   In high-school, our electronics teacher had two spots painted on a
> > > > long strip of card-board.  It was his tera-ohm resistor!  :)
> > >
> > > LOL!  I've done that.  Also thumb tacks in a 2x4.  It varies greatly
> > with
> > > humidity though.  For making custom resistors, draw a line of india ink
> > on
> > > a plastic surface, let dry, then cover it with tape.  For really high
> > > resistance, use diluted ink.
> > >
> > > (((((((((((((((((( ( (  (   (    (O)    )   )  ) ) )))))))))))))))))))
> > > William J. Beaty                            SCIENCE HOBBYIST website
> > > billb@eskimo.com                           http://amasci.com
> > > EE/programmer/sci-exhibits   science projects, tesla, weird science
> > > Seattle, WA  206-789-0775    sciclub-list freenrg-L vortex-L webhead-L