CHIA YU TENG,DEE on sun 8 sep 96
HI!!! :) :)
I am about to expose some silkscreens with images on overheads as part of
my current honours project. In Singapore, I can get emulsions for sensitizing
some hand made emulsions...BUT ..:P have no recipes at hand... Does anyone
out there have anything to share?
Thanks in anticipation :) :)
DEE CHIA
BobWicks@aol.com on mon 9 sep 96
HI DEE CHI:
Recipe for Direct Sensitized Silk Screen: (All water used must be slightly
acid. I recommend either rain water or distilled water unless you have
proven that your tap water has the right ph)
BLOCK OUT
One part Knox Gelatin mixed with water as directed on box to one part Fish
Glue or photo glue.
Add water color for visibility. Solution should be heavy enough to fill in
pores of the silk with no lumps.
SENSITIZER
3% solution of Ammonium Dichromate stored in a amber glass bottle. (4 level
teaspoons to a quart of water or 29.5 grams of Dichromate to 125
milliliters distilled water)
A. 50 milliliters distilled water added to 1/2 level teaspoon gelatin
powder. Allow to stand for 15 minutes.
B. Fish glue or photo engravers glue is mixed with the gelatin solution half
and half.
C. Dissolve 29.5 grams Ammonium Dichromate with 125 milliters of distilled
water and store in an amber bottle, using a non metal cap. This will keep
indefinitely in the amber bottle.
D. Stir 4 parts of the gelatin and glue mixture with 1 part of the
Dichromate sensitizer. This mixture must be used within one hour and it is
toxic. Wash off immediately if you get it on your hands.
To make screen, water resistant add 1 part Formaldehyde (40% solution ) to 9
parts distilled water painted over he entire screen after development.
Development must be carried out with, slightly acid water or the blockout
will dissolve.
Exposure: Use a #2 photoflood for about 6 minutes 10 inches from screen or
sunlight on bright days for about 5 minutes. (adjust time to suit yourself.)
If you have any other questions on this use E-Mail.
Bob
| |
|
