LIGHT TABLE
IMPORTANCE OF A LIGHT TABLE & CONSTRUCTION
IDEAS
Paul Crist: A light table can be very useful in selecting the particular
part of a sheet of glass to use, as well as seeing how all the glass pieces
you have cut work together. The light table should be illuminated by light
bulbs rather than fluorescent tubes, as incandescent light will be your
ultimate light source. Incandescent light is somewhat warmer in color
than either fluorescent light or daylight, so glass will apear different
in each. We have found that the wattage necessary to properly illuminate
glass on a light table is far greater than the wattage required to illuminate
the lampshade when it’s finished. 100 watts per square foot of light
table surface is a good rule of thumb to follow. The glass covering the
light table should be clear, because frosted glass will change the apparent
opacity of your glass, as well as obscuring some subtler effects.
Carol Conti: In order to see how your glass will look when light is transmitted
through it, I think a light table is absolutely necessary. Here is a very
simple way to build one: place a piece of 1/4” clear plate glass
(at least 18”x24”) on top of four support bricks or blocks
of wood (4”x4”x6”). These supports should be positioned
at each corner of the plate glass. Attach a spring clamp light fixture
to a corner block and illuminate it with a clear incandescent light bulb.
If you decide to build or purchase a more substantial table, remember
to ventilate it so that the build up of heat generated from the light
bulbs can be eliminated. A dimmer switch is helpful to have in your light
table. If you raise the back of the plate glass up at a 20 degree angle,
you will be able to sit at the light table and not be bothered by the
light bulbs.
Al Zimmerman: In a pinch, you could use a glass-top dining table with
a lamp under it for your light table!
Mike Barnes: In addition to my light table, I have a large 1/4 inch x
40 inch diameter glass table top that I use to display my assembled pieces
after they’re cut. The table top sits on two saw horses with lights
underneath. This provides me with an alternative method of selecting glass.
I can hold a piece of glass under this table top and see how well it would
work with the pieces that are already displayed.
Vic Seeted: I built my light box on dimensions that I thought I wanted
and what would work for me. Mine is 52”x52”. I rebated the
edges an eighth of an inch for the quarter inch (beveled edge) plate glass
to fit into. I installed lamp sockets into the sides. I added two moving
pieces on the bottom - installed each with a lamp socket and connected
them together. This allows me to light the entire project and to move
the two bottom pieces around to see the interplay of light at different
angles and different perspectives- just as your completed shade would
look when it is lit.
Twyla Morgan: My grandson’s Foosball (air hockey) game has made
its way to my glass studio! As I was looking at it, I noticed all its
similarities to my light box. If you could pick one up cheap at a garage
sale, it would be easy to wire and then place glass on its top. The long
rods are removable which would leave holes along the sides for wiring
and ventilation.
Kevin Hendon: I am re-thinking my studio’s light box and want to
change it to handle a full 360 degree layout for a pattern. What would
be the minimum requirement for the box?
John Cannon: Take the pattern for the largest shade that you plan to build
and lay it out on a flat surface. Mark the outer edges of the pattern.
Move the pattern around to add the second repeat; mark these edges. Repeat
until all the pattern repeats are 7 marked. Measure the total width and
length of the pattern repeats and add a few inches to both dimensions
to give yourself some “working” room. Use double strength
glass for your table.
Deb Bowen: My round light table is made of 1/4 inch tempered glass with
a slightly beveled top edge. The table is 41 inches across and will accommodate
most of the lamps that I build. A downside to having a larger sized light
table is that, when working on smaller shades, you will need to lay black
paper over the edges to keep the light from penetrating through to the
unused parts of the table.
Peter Grotepass: We have three light tables in our studio; all of them
are round and have diameters from 30 to 48 inches.
Chaz Smith: When I use a light table, I draw the pattern on the glass
of the table and then draw a dotted line across where the bulbs will be.
When I hold the glass over the table for selection, I put the bulb under
the dotted line and then angle the glass over its appropriate place on
the pattern.
Julie Stearns: I finally got a decent sized light table! I bought a used
round coffee table that had a 30” glass top and wood bottom. My
husband wired it and placed 4 light sockets in the bottom. He cut a sheet
of white plastic ceiling light panel in half to go around the inside to
keep in reflected light. We spent less than $50 for everything!
Kevin Hendon: I want to share an amazing discovery that I place in the
“DUH” category! I was fitting the 22” Tulip on the mold
- a shade that has an amazing vertical apron that defies gravity. Thinking
about my predicament of not having enough wax or how to defy gravity,
I decided to rewax the last third and left the last glass easel on the
light box. What a discovery...the light box warmed the pieces so, when
I transferred them to the mold, they adhered to the wax and STAYED.
note: Kevin has one light table on which he selects glass, another table
to hold finished repeats for comparison and another table is used to build
repeats.
Vic Seested: I wonder if it made any difference if you used frosted glass
instead of clear glass for the top of a light table or if you used frosted
bulbs instead of clear bulbs to light the table.
Ichiro Tashiro: In my opinion it makes quite a difference. It even makes
a difference in a lamp. Try using a clear light bulb and a frosted bulb
in your lamp. Place the lamp in front of a white wall and see the difference
each bulb makes on the wall.
Kevin Hendon quoted Paul Crist: The glass covering the light table should
be clear because frosted glass will change the apparent opacity of your
glass as well as obscuring some subtler effects.