Dave
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This page is from years back when I had a lot of plate glass to
sell. I thought I would leave the page up because there's some hard to
find
info here. This page has also been one of the
more popular pages on the site so I'll come back and add more info as I
find it.
I don't have any more plate glass to sell.
Like big glass?
Great stuff for sandcarving (sandblasting), sculpture, or other big art
projects, not to mention using it in buildings for skylights,
windows, greenhouses, aquariums, or for building telescope parts.
Even the broken or water stained pieces are good for glass bead making,
sandblasting, frosted glass, Dalle de Verre, or any hot or cold glass
artwork requiring smaller pieces.
How Much Does Plate Glass Cost ?
Let me give you a link that will give you a good idea.
www.get-a-quote.net
It's a webpage for estimating construction costs. When you get to
get-a-quotes' home page, pick your state, or a state near
you. When you get to the page for your state, enter "plate glass" into
the search engine, and it will take you to the page with the wholesale
prices. You may have to scroll down quite a ways, there's lots of info
there.
Water Stained or Devitrified Glass
Water stains and/or devitrification on glass happen when glass sits
with water on it for too long. The alkali in the glass combines with
the water and leaches out of the glass, leaving behind a "skeleton" of
silica that looks sort of like a sponge. This is the cloudiness you see
on the surface of the glass. The alkalai is originally put into the
plate glass at 12-15% to lower the melting temperature of the sand.
Books on Art using Plate Glass
"Glass An Artists Medium" by Lucartha Kohler is the best (and only)
book I've found so far that does a good job showing you all that's
being done with plate glass as high quality art.
The book goes into large and small scale work with some of the best
ideas, gorgeous work and agood bit of tech info. It covers a lot of
other types of glass art with the same quality level, specifically,
Furnace, Lampwork, Casting,
Fusing, Slumping, Surface Decoration and Cold Working. The piece you
see on the cover was done with plate glass.
Finding Thick Plate Glass
Look around locally for a window/plate glass shop or warehouse that
works with the thicker plate glass. They may have some "drops" from
cutting pieces or broken pieces. Unfortunately, the thicker (over 1/2")
plate is getting harder to find.
Watch for it on Craigslist. Also watch Craigslist for furniture with
pieces of thick plate glass used in their make up, things like glass
top tables, desks, shelves. Read the part below about the exploding
plate glass!!! My buddy Tom mentioned below bought a lot of really
thick plate glass tabletops as cheap furniture in a close out store
something like Big Lots. The whole table was way cheaper than a piece
of plate the same thickness.
Fusing Water Stained or Devitrified Glass
Update on badly water stained glass for fusers:
My friend Tom Fuhrman
has been using plate glass for some gorgeous and unusual art glass
fusing
projects. The water stains actually produce a very interesting effect
when fused, sort of like old glass from archaeological digs. Contrasts
nicely with sandblasting. I guess you could say this is a limited
edition effect. How many people are going to leave their plate glass
out in the rain for ten years to get this?
Tom has also done some amazing sculptures using epoxy to glue the plate
glass together or to other surfaces. Tom did a waterfall where the
glass was glued to masonry with the water running over the glass. I
didn't think it would hold but it's still there and it was done at
least ten years ago. He did another one with end polished plate epoxied
together into the shape of two pyramids base to base. It's suspended in
the entrance to a hospital there in TN. It's as big as a car and
it took a crane to hang it.
Melting Plate Glass in Your Furnace
For the hot glass folks, the c.o.e. of this is low to mid
eighties. It's just plain old soda lime glass. This glass is also very
(too?) stiff to work hot from a furnace without adding some
alkalai and maybe borax to soften it up.
About Tempered Plate Glass
Tempered glass is made when the glass is still hot from being
manufactured. They squirt it with a blast of cold air on both
sides. This causes the glass to end up with a large amount of
compression stress on the outside skin.
This stress actually makes the glass stronger. It's much
harder to break a piece of tempered than it is regular glass.
If you do break tempered glass, it doesn't break
into sharp shards like regular glass, but becomes "crumbs" that don't
have very sharp edges.
You can NOT cut, sandblast, scratch, or grind tempered glass without
having it shatter explosively on you.Tempered glass is mainly used for
security and as a safety glass in showers, patios, doors, shelves or
any place that might get someone hurt if they broke the glass.
To reverse the tempering so that you could cut, grind, sanblast, etc.
you have to run the glass through an annealing cycle in a kiln. This
relieves the external stress in the glass.
My friends Sky Campbell and Sarah Hinds were making some really nice
fused glass
pieces using the "crumbs" from tempered glass laid out in a pattern and
fused. Think snowflakes as an example. Junkyards are a good source for
these pieces. The side windows in all cars are tempered glass by law.
Cutting Plate Glass
I learned a trick for cutting plate glass that's 80-90%
successful. Thanks to glass artist Dave McClary for showing me how to
do this.
The way the cutting trick works is:
- Score the plate on top with a regular glass cutter.
- Wet the score. This helps it break evenly.
- Put a small pipe or wood dowel under the glass (with
a towel over it to prevent scratching) lined up right under score. The
score is
on the top side of the glass.
- Lift the glass and drop it on the pipe/dowel.
- This will not cut pieces smaller than about 12".
- This will not work on tempered glass (explosion!).
- It doesn't work on water stained glass (can't get a
good score).
Exploding Plate Glass
You've probably heard the stories on the news. Plate glass patio tables
(and other plate glass) exploding at random.
The news folks think it's a mystery, but it's not. The glass is not
being melted correctly and the "why" has been known for quite a while.
Or, should I say, it's been known here in the US. The problem glass is
coming from China.
Check out the book Falling Glass by Patrick Loughran. In the
first chapter it
explains what's happening to cause the mystery glass explosions and the
rest of the book goes into a lot of other mistakes made over the years
leading to major accidents with plate/big glass. It's an important read
if you're doing art or anything else with large or plate glass so that
no one gets hurt. Some things about hanging glass are counter
intuitive.
You can spot the "mystery explosion" problem in plate glass before
it happens by using a polariscope. The polariscope will let you see the
stress in the glass.
For the polariscope page click HERE
The problem is hard spots or "stones" (glass melting term)of nickle
sulfide left in the glass after melting. That comes from low quality
ingredients used to melt the glass. Those stones cause
huge internal stress right up until the moment when the glass lets go
in an explosion.
This stress can go as high as 50-60000 p.s.i. before the glass lets go.
You can see why it explodes.