'Ello people, hope all is well....
I've asked all the questions about the set-up im using and all that was left for me to do was to test it...
- Just to recap i'm using a the basic speedball Diazo emulsion kit. I decided to use just the one single 500watt halogen floodlight and I re-measured my screen size which gave me a height of 22" for the distance between light and screen (roughly)...
- Every other post i've seen here that has used a single 500watt halogen bulb suggested a time of 15 minutes roughly (although that changes with different emulsions), so i began trying to test the time i needed for my own.
Here are a few images of my first test: - I only coated a strip of emulsion on my screen so i didnt waste a load of it.
- I didn't use a piece of glass to hold my acetate down which was a bad idea... the heat from the bulb started to turn the edges up on the acetate and it no longer sat flat on the screen (but this was only a test).
- Like testing exposure for photography prints, i used the same method for this screen test in 2 minute steps up to 20 minutes.
this first image is to show the exposure steps... however it looks as if 15 minutes isn't needed. here you can see 2mins exposure on the right, the strip of 4mins, a VERY faint strip of 6mins and all the others (8/10/12/14/16/18/20 mins) dont show up. hopefully meaning i only need 4-6 mins exposure time.
This second one is a closer look at the screen.
Red circles: these dark dots look either like clumps of emulsion or small fibres etc stuck in my mesh..(i stupidly tried dryin my screen with kitchen roll..bad idea).
Green circle: this looks like it could be air bubbles in my emulsion, i mixed the sensitiser and then coated a strip. i guess i should've waited a few mins after mixing??
Blue circle: this will roughly be about 14-16 mins of exposure where it was more difficult to wash out (i had to get a pressure washer on it!) This final image is a little comparrison between original stencil and washed out stencil. When first washing out, i thought 2 mins would be ample time, however after gently washing out and then pressure washing the rest of the emulsion began washing out. the Red outlined bits show where my stencil was accurate with a 2 min exposure, however the green circle shows the rest of the emulsion breakin down and washing out where i didnt want.
I was just wanting some clarification really, that judging from my test(photos), 4-6mins would be sufficient for future screens (even though i will be adding a thing sheet of glass over future designs)...
thanks very much
Chris
.: My 1st screen exposure test:. UK 
im just worryin about nothing really... :P
