Filling Holes in Glass

I'm in the process of doing an experiment on the temperature
distribution and lag in a thick piece of glass and was looking for
some advice.
I've had a 45mm thick piece of glass drilled with water jet cutting
(no one in my area was willing to drill glass this thick and the
waterjet person was cutting with under a clause of "all care no
responsibility") and now need to back fill some of the holes to a
particular depths.
I was initially thinking of using Nylon cylinders but as it happens
the holes aren't circular, some are literally 'pear' shaped. I need to
make sure what's used to fill the holes can seal as well, as there
will be a layer of thermal conductive material going in for the
thermocouples.
Is there anything in the market that I could use, a foam perhaps, or
even an araldite that could be fed in to the required depths to 1)
insulate the hole from the outside and 2) give a good, hard stop for
the thermocouple.
Thanks for your help
Haiiro

Two products to try. Check them out first for your requirements
100% Silicone Sealant also sold as tub caulk, will give a firm, but not
hard, water tight seal. As with all adhesives clean the surfaces before
applying.
E6000 or the Goop products will give a much harder surface. E6000 is self
leveling and flows (and stinks a lot) so will require tape or something to
keep it from leaking out of the hole. Some of the Goop products variations
have variations, like UV resistant and non-flowing, that can easily be found
in the descriptions on their web site http://eclecticproducts.com/index.asp
.. Somewhere on the site was a table of tradeoffs, but I can't find it now.

--
Mike Firth
Hot Glass Bits Furnace Working Website
http://users.ticnet.com/mikefirth/hotbit46.htm Latest notes

"TB" wrote in message
om...
I'm in the process of doing an experiment on the temperature
distribution and lag in a thick piece of glass and was looking for
some advice.
I've had a 45mm thick piece of glass drilled with water jet cutting
(no one in my area was willing to drill glass this thick and the
waterjet person was cutting with under a clause of "all care no
responsibility") and now need to back fill some of the holes to a
particular depths.
I was initially thinking of using Nylon cylinders but as it happens
the holes aren't circular, some are literally 'pear' shaped. I need to
make sure what's used to fill the holes can seal as well, as there
will be a layer of thermal conductive material going in for the
thermocouples.
Is there anything in the market that I could use, a foam perhaps, or
even an araldite that could be fed in to the required depths to 1)
insulate the hole from the outside and 2) give a good, hard stop for
the thermocouple.
Thanks for your help
Haiiro

At your local hardware store, ask about spray foam insulation.

This stuff sells at around $15 a can, I think, on the doit-yerself level.


Chris (the unwise)

May God make you, and everyone whose lives you touch, HOLY. May you let
Him do so.



TB wrote:
I'm in the process of doing an experiment on the temperature
distribution and lag in a thick piece of glass and was looking for
some advice.
I've had a 45mm thick piece of glass drilled with water jet cutting
(no one in my area was willing to drill glass this thick and the
waterjet person was cutting with under a clause of "all care no
responsibility") and now need to back fill some of the holes to a
particular depths.
I was initially thinking of using Nylon cylinders but as it happens
the holes aren't circular, some are literally 'pear' shaped. I need to
make sure what's used to fill the holes can seal as well, as there
will be a layer of thermal conductive material going in for the
thermocouples.
Is there anything in the market that I could use, a foam perhaps, or
even an araldite that could be fed in to the required depths to 1)
insulate the hole from the outside and 2) give a good, hard stop for
the thermocouple.
Thanks for your help
Haiiro

(TB) wrote in message . com...
I'm in the process of doing an experiment on the temperature
distribution and lag in a thick piece of glass and was looking for
some advice.
I've had a 45mm thick piece of glass drilled with water jet cutting
(no one in my area was willing to drill glass this thick and the
waterjet person was cutting with under a clause of "all care no
responsibility") and now need to back fill some of the holes to a
particular depths.
I was initially thinking of using Nylon cylinders but as it happens
the holes aren't circular, some are literally 'pear' shaped. I need to
make sure what's used to fill the holes can seal as well, as there
will be a layer of thermal conductive material going in for the
thermocouples.
Is there anything in the market that I could use, a foam perhaps, or
even an araldite that could be fed in to the required depths to 1)
insulate the hole from the outside and 2) give a good, hard stop for
the thermocouple.
Thanks for your help
Haiiro


Two thoughts come to mind. The first would be to either put a nylon
bolt/nut in place and then drill that. The second would be to epoxy
or use an adhesive to bond a piece of nylon, UHMW, or some acrylic rod
in place. I suppose you could even bond in a piece of glass tube by
an adhesive or reflowing some glass to hold it in place.

By the way, when you attach the thermocouples be sure that you keep
the leads along the surface for a bit away from the measuring point.
Otherwise you could introduce measurement errors due to thermal
shunting. The TC wires would act like a fin to change the target
temperature.

Bill

Thanks for your help. I'll try the suggestions mentioned and might
(memory and time prevailing) get back to you on how it went
Haiiro

On 21 Nov 2004 16:39:16 -0800, (TB) wrote:

Is there anything in the market that I could use,

Be careful with silicones. They cure by releasing acetic acid
(vinegar) and this will corrode thermocouples or strain gauges. There
are some "electronics safe" silicones around.

There are also mirror mounting mastics (cheap, from a hardware store)
that are safe with silvered mirror coatings. I think these are a
similar modified silicone.

If you need something mechanically stronger, look at solid
polyurethane mastics. These are used on boats for the same purposes as
silicones on bathtubs - much stronger and resistant to almost
anything. I use the Sikkaflex products, from a local boatyard.
--
Smert' spamionam

Any of the potting compounds from either Dymax or Loctite will work but you
will need a UV light source. Black light works as does the sun. There may be
some that can be catalyzed but I do not recall. I would suggest you call
either of the two companies. They have very good tech service. There is
usually a distributor in your area for Loctite but don't know about Dymax.
Dewey and Associates is a distributor of Dymax products and has excellent
telephone help.



On 21 Nov 2004 16:39:16 -0800, (TB) wrote:

Is there anything in the market that I could use,

Be careful with silicones. They cure by releasing acetic acid
(vinegar) and this will corrode thermocouples or strain gauges. There
are some "electronics safe" silicones around.

There are also mirror mounting mastics (cheap, from a hardware store)
that are safe with silvered mirror coatings. I think these are a
similar modified silicone.

If you need something mechanically stronger, look at solid
polyurethane mastics. These are used on boats for the same purposes as
silicones on bathtubs - much stronger and resistant to almost
anything. I use the Sikkaflex products, from a local boatyard.