the true diyers screen printing

Step 5 Exposing your screen

I have a reflector I bought from lowes for $8, and has proven to be worth it. since this is homemade emulsion tests will need to be done as far as exposing time goes, I know my 18" X 17" take 15 - 20 min. to expose. if you happen to try this please post your personal times and heights etc. I tape my designs down on one side. This prevents from the design moving around and since there's only one it works as a hinge and allows you to see the difference in colors from the exposed to the non exposed parts of the screen. Also if the screen is not ready the tape allows you to place it back down with out any movement of the design. ( hence referring to it like a hinge)

Comments

[awsmanna]

How far away is your lamp from your screen? I was trying to do this with the sun, but a thin layer of emulsion completely rinsed away after 30 min, and a slightly thicker layer wouldn't rinse out after 30 min. I'm going to start over again tomorrow and do a full screen of test exposure times to nail it down.

[slimguy379]

idk haven't done this in a long time, i bet a matter of a foot or so

[loergias]

not to be mean, but along came the bigger fish (in the ecology of the world of instructables): http://www.instructables.com/id/Photo-emulsion-Screen-Printing/step1/Gather-your-materials/

the author explains 150w incandescent no less.

so that ans the question i sought.

but not to shame, i could have never found a better stepping stone than your personal instructable.  without it, i would have never found the bigger fish, so to speak.  sorry i speak in eternal signs and metaphors.  bear with my charades.

[cynreams]

This is actually only for the Speedball Diazo emulsion system.  Not for homemade emulsion, so it might not work for all emulsions.  What she has listed is taken verbatim from the Speedball diazo photo-emulsion system instructions.  So, if you are making this emulsion yourself from this instructable, the link listed above may not work.  So keep trying!!  You'll get it.  I'm going to try making my own next week when my supplies arrive, so we shall see!!!

[plasticpopcorn4]

What does the light do to the solution? dissolves it?

[slimguy379]

no it exposes the screen with the goo, the pattern (black designs) do not allow light to pass, and allow the goo to harden. this stays soft and easy to wash out. thus creating your screen

[loergias]

what color light goes into making such a "burning" take place with that 15-20 min time frame you discretely use??  i would imagine a single light bulb in the range of a 50-100 watts, incandescent type bulb??  sorry, i know i'm removing the experimental phase of getting up and starting my own business of this DIYer's dream, but from one aspiring soul to another would you help make this go a lot smoother by adding more input on this matter (of lighting)? 
      i read somewhere the best is using direct sunlight for approx 7 min will achieve the best results.  this of-course seems to be the most environmentally friendly way, but this seems to be uncontrolled and possibly more left to the whim of nature and all its glorious mishaps (i.e. weather, clouds, rain).  but then again, who's to say this is actually totally foolproof??  a full 7 minutes seems to be within one's own command, if all the business is attended to properly in a methodical sort of way.  ok, enough of me thinking out loud.  so, please, if you will.  more details of the lighting you're using for your makeshift "darkroom."  or, would "lightroom" fit more appropriately?  idk, i'm sort of new to this "photo emulsion" technique.  i'll need a little firelight to guide me through, until i'll be able to feel my way through the "dark," so to speak.  --having found my own zen in the art of screen printing.

thanks much for this rather informative tidbit.  power to the people!!!