Re: ATM Softening pitch - heritical thoughts

["Richard Schwartz" <richas@earthlink.net>]

> [Original Message]
> From: Kevin Whitefire <chaosopher23@yahoo.com>
> To: Art <mock47@accessbee.com>
> Cc: <atm@shore.net>
> Date: 1/16/2004 1:01:04 PM
> Subject: Re: ATM Softening pitch
>
>
> --- Art <mock47@accessbee.com> wrote:
> > 
> I couldn't find real turpentine.  I tried min spirits,
> and they worked fine.  It was a burgundy pitch, I
> think it was Gugloz.  I do hear that turpentine is
> best.
>
> > 1. I have one kilo of Gugolz 74, I have read to
> > soften it with mineral
> > spirits and also never to use mineral spirits, but
> > to use turpentine
> > instead.  I have also read to use bee's wax.  
>
> Use beeswax to coat the tiles, if you like.  I've
> never used the stuff.

The problem with turpentine, and "turpatine" (mineral spirits) is that it
evaporates from the surface of the pitch lap after a time, leaving a hard
crust over a soft interior.    Two ways to soften pitch are better: (1)
bee's wax, and (2) castor oil.    With castor oil, only a single drop will
soften the pitch lap, and the remainder of the bottle can be sent as a gift
to Texereau and Hindle with instructions that they are to DRINK the stuff.

> > 
> > 2.  Should one be able to perform an adequate
> > Foucault test on a 5 micron
> > ground mirror?  Or is it usually necessary to have
> > some polishing?
> > 
> Finish it to at least fully polished.  I polished from
> 9u with good results using zirconium oxide and pitch.
>

You cannot do a foucault test on a mirror until it is polished.  But there
are plenty of other tests you can do to verify the quality of the fine
grind.   Most of them are not described in any official book or journal, so
they must be considered heretical.  See my web page,
www.megspace.com/science/sfe. 

> > 3.  I am thinking of heating the pitch out in my
> > back yard using low heat
> >  from a propane camp stove.  Is this suicidal?  Can
> > it be done safely if one
> > is carefull to keep the flame low and go slowly?
> > 
> Your best bet is to use a hot plate.  Hardware stores
> still sell these things and they are cheap.  While
> pitch is flammable, it is not an explosive.  Suicide
> would be difficult at best with the stuff.  It's
> better to drop a ton on yourself than to accidentally
> burn some nearby if that's your plan <weg>.

I don't know why you think the pitch must be heated outdoors.   It is a
cultural thing.  Some cultures think pitch is a terrible stink, and others
are reminded of the fresh smell of a pine forest far from the Los Angeles
air pollution.   I have found that the best way to heat pitch is to place
it in the kitchen oven at about 170 degF.    This is a slow way to heat it,
but by adjusting the temperature, you get precise control over the
thickness of the pour.   You will never, ever scorch the pitch if you heat
it in the oven.   This is not mentioned in any books or journals, so it
must be heretical.

> > 4. Other than perhaps teflon, is there any easily
> > acquired substance to
> > which pitch will not adhere?
> > 
> I don't know.  I think pitch will stick to everything,
> including teflon.

Pitch will not stick to a cerium oxide slurrry.   I guess this is not so
heretical, except for the use of cerium instead of rouge.

> > Would it for instance be feasible to rout several 1"
> > x 12" x 3/8" deep slots
> > in a 1x12, soak the slotted areas in motor oil or
> > some sort of release
> > agent.  Pour the pitch to the thickness desired,
> > remove it before it became
> > brittle and perhaps cut it into 1" squares using a
> > hot knife or such tool?

I experimented with the texereau strip method, and did not like it.    I
like to start with the pitch a little on the cool side so that it pours
thick.  Pour it onto the foundation and correct any irregularities with a
chopstick.    I use a hot chef's knife or mad cow cleaver to cut the
channels with the BACK of the blade.


> I used the gooey drop method.  Using a small metal
> measuring cup, or a tablespoon, scoop out some hot
> pitch.  It should flow like motor oil that needs
> changing on a cold day.  You know the stuff - gooey. 
> Drop it on your tool and let it harden.  Quarter - to
> - dollar sized pieces work for me.  No molds, no hot
> knife.  Chisel the edges off before you polish.

Hmmm... I have not tried this, but it sounds good.   Probably there are
large spaces between the facets so that the channels never close.   I HATE
to say anything good about another person's idea!   But at least it is
heretical: it does not appear in any published book or journal.

> > 
> > Finally, during the fine grinding the ceramic tiled
> > surface of the tool
> > seemed to be as smooth as the glass of the mirror. 
> > This begs the question
> > is there any possibility of using ceramic as a
> > mirror media?
>
> Ceramics are used, but glass is still superior.  Get a
> disk of ceramic and a tool and see if you can make a
> little mirror from it.  4" shouldn't be too expensive.
> > 

Richard agrees.   There are all different kinds of ceramic tile, and how do
you know what you are getting?  There is only one way to know for sure if
this idea will work.   I think you know what must be done.   Here is a real
opportunity to contribute to the state of the art!


> > I didn't mean to make this post so long. . .
> > Thanks for any help.
> > 
> > Arthur Mock
> > Fresno, CA
> > 
> At least you didn't shaggy-dog it like I have in the
> past.  I can get long-winded!
>
> Kevin of Eastern Iowa
> Seeker of the Darkness

Kevin is OK, just a little bit tradition bound.    Richard is a mad-dog
heretic!

. . . Richard