HomeRoast Digest


Topic: drilling pyrex (12 msgs / 222 lines)
1) From: stereoplegic
anyone know how to go about doing this? even though i'm loving my new 
eWOK/CO setup, i found a pie tin-shaped pyrex dish (flat w/ 
steep-sloping sides) that i'd love to use in an SC/CO (CO because mine's 
not a sunpentown or GG) type setup. i've already got a nice strong motor 
and stirring arms ready to go. i just don't want to start drilling this 
dish until i know how to do so w/o breaking it, if at all possible.

2) From: Lynne Biziewski
VERY carefully....
anyone know how to go about doing this?

3) From: Jim De Hoog
I haven't drill pyrex, but cut a hole in a glass block using a grout cuttin=
g bit for my rotary saw.  Took it easy as I went through the glass block.  =
The tip of the bit would heat up red hot and start melting the glass if too=
 much downward pressure was applied.  I don't think that my wife would let =
me try it on one of her pyrex dishes. They do make glass cutting drill bits=
.
Jim "Ice Bucket Roaster" De Hoog
----- Original Message ----=
From: stereoplegic 
To: homeroast=
ias.com
Sent: Thursday, January 18, 2007 10:05:15 PM
Subject: +drilling=
 pyrex
anyone know how to go about doing this? even though i'm lovi=
ng my new 
eWOK/CO setup, i found a pie tin-shaped pyrex dish (flat w/ =
steep-sloping sides) that i'd love to use in an SC/CO (CO because mine's=
 
not a sunpentown or GG) type setup. i've already got a nice strong moto=
r 
and stirring arms ready to go. i just don't want to start drilling thi=
s 
dish until i know how to do so w/o breaking it, if at all possible.
=
homeroast mailing list
=http://lists.sweetmarias.com/mailman/listinfo/homeroastTo change your pe=
rsonal list settings (digest options, vacations, unsvbscribes) go to http:/=
/sweetmarias.com/maillistinfo.html#personalsettings

4) From: Eddie Dove
I have not specifically drilled Pyrex, but for cooling, build a little
"volcano" around the area with Plumber's Putty and fill with oil; it helps
with cooling too.
Hope this helps ...
Eddie
-- 
My Home Coffee Roasting Blog and Profiles for the Gene Cafehttp://themeyers.org/HomeRoast/On 1/18/07, stereoplegic  wrote:">http://southcoastcoffeeroaster.blogspot.com/Sweet Maria's List - Searchable Archiveshttp://themeyers.org/HomeRoast/On 1/18/07, stereoplegic  wrote:
<Snip>

5) From: TERRY TITSWORTH
Drilling Pyrex is a little tricky. Two methods can be used by the home
hobbyist. One method would require a drill press that would allow you to
feel the pressure being exerted on the Pyrex. It would also require the
building of a water dam to surround the area to be drilled. A brass cutting
tube with Carborundum would do the actual cutting of the hole. The brass
tube is sold by glass cutting tool supply outlets and come in different
diameters and styles. The Carborundum should also be carried by the same
supply company.
The process would entail using something like modeling clay to form a circle
around the area to be drilled, with enough height to allow water and
Carborundum to stand 1/2" to 3/4" in depth. The piece to be drilled would be
centered under the drill tube and the water and Carborundum mix would be
poured into the circle. Remember that the exact spot to be drilled must be
positioned exactly under the tube before you add the mixture as you will not
be able to see any marks after the mix is added. Secure the Pyrex so that it
does not move after being positioned. If the project is NOT firmly secured
it will move and possibly break should the drill tube bind while drilling.
Turn the power on the drill press and slowly lower the drill tube until you
feel the end of the tube pressing against the Pyrex. The Carborundum is
doing the actual cutting, or more accurately grinding away of the Pyrex and
it is important to keep the mixture wet during the drilling. The Pyrex will
get hot and crack if the mixture gets too dry. A slow steady pressure will
do the best job. Depending on the thickness of the Pyrex the drilling from
start to finish could take upwards from 5 to 8 minutes. Remember, your not
drilling wood or metal but a product that has the same characteristics of
glass. So don't lean on the drill press handle. Take your time.
The second method is similar to the first with the exception of the drill
press and drill tube. Instead you would use a hand drill and a spade or
three sided glass drill. the same set-up would be required for the water dam
and Carborundum. With this method you would start the hole for a point of
reference then add the mixture to drill the hole. This method is a little
easier for the hobbyist because most people have a hand drill but not a
drill press. Both take about the same amount of time for set-up and drill
time.
The trick to these processes is keeping the surface cooled with fluids and
not to get in a hurry or apply too much pressure. Rubbing alcohol can be
used in place of the water as it tends to evaporate and carry away the heat
a bit better for use on Pyrex. But you have to keep pouring it into the
solution to keep it wet.
Another solution would be to take it to a glass shop if they don't charge
you took much.
Sorry to take up so much time and space.
Keep use posted as to how your project works out.
On 1/18/07, stereoplegic  wrote:
<Snip>
-- 
<Snip>

6) From: stereoplegic
thanks for the replies everyone. this might be a little out of my league 
for now (although, that's what i thought about split-wiring air poppers 
when i first started this addiction-er um, hobby, yes, it's a hobby: i'm 
not an addict, i can quit any time i want, i'm just having fun...). i 
think i'll just pester a few glass shops for now...
stereoplegic wrote:
<Snip>

7) From: Michael Dhabolt
A method similar to the one Terry spelled out but using a diamond hole bit
and using running water as coolant has worked for me....the diamond hole bit
can be purchased at rock shops and/or jewelry supply houses (aren't nearly
as expensive as it sounds).  A real slow drip of coolant (water works well
with diamond and borosilicate glass) without a dam will help clear the
machining site (one drop of dish detergent per liter of water).
Now comes the hard part.  In my experience the pyrex piece needs to have the
hole 'flame polished'.......a glass blower will just barely melt the glass
where it was machined.  The piece then needs to be annealed by raising to a
fairly high temp (not melting temp) and slowly cooled (again glass artists
usually have a seperate annealing kiln).  All of this is necessary because
glass and specifically borosilicate, more than other glasses, develop
serious stresses when virtually any work is done on it.  I've known pieces
to last without going thru this routine (when treated extra
tenderly).....but if it is in a roasting situation (heat up and cool down
regularly) I've had poor luck with pieces that weren't given the whole
treatment.
If you have anyone locally that builds laboratory equipment, they'll do it
quickly and cheaply for you - with a high success rate.
Mike (just plain)

8) From: Alchemist John
Having split wired my own popper, voltage boosted my popper, and 
built 3 of my own drum roasters, drilling pyrex was beyond me.  The 
"trick" is to keep it cool, but all the tips (ice, dripping water, 
cone of putty, etc.) never worked.  I cracked it every time (due to 
heat).  With some glass cutting (note, not drilling) behind me, I can 
offer this.  You need a continuous supply of water.  A lot.  Not a 
drip.  Not a trickle.  Go outside and fill the pie plate with water 
from a hose and leave the hose on overflowing.  Then drill.  Oh, the 
drill.  Diamond tipped grinding bit.  A standard metal bit will just 
throw the water out.  Finally, with that much water, keep safety in 
mind in regards to the electricity you are using.
At 22:52 1/18/2007, you wrote:
<Snip>
John Nanci
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.chocolatealchemy.com/

9) From: Dan Bollinger
I believe it is regular glass that is drillable. Why drill Pyrex (borosilicate 
glass)?  Use a blow torch to heat the area until it glows, then use a piece of 
thin walled brass tubing like a cooky cutter and punch a hole.
I'm pretty sure this works, it's been a long time since I messed with pyrex. 
You might check some glass forming techniques online.
Dan
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10) From: Cameron Forde
Most bigger universities will have a glass blowing shop (especially if
they have a large chemistry department) that can do this for you --
for a price (depending on the shop it could be free considering it is
not a big job, and you could offer to pay in coffee).
Cameron

11) From: James
This will work in theory, it mostly depends upon how casual the  person in =
the glass blowing shop will treat the matter. For safety and  labor concern=
s, most shops will require you to go through official  University channels.=
 If that is your only option, fuggedaboutit. 
    
  James in Southern =
CA.
----- Original Message ----
From: Cameron Forde 
To: homeroast
Sent: Friday, January 19, 2007 =
12:00:32 PM
Subject: Re: +drilling pyrex
Most bigger universities wi=
ll have a glass blowing shop (especially if
they have a large chemistry d=
epartment) that can do this for you --
for a price (depending on the shop=
 it could be free considering it is
not a big job, and you could offer to=
 pay in coffee).
Cameron=

12) From: stereoplegic
thanks again to everyone for the wealth of feedback i've received on 
this topic.


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