Author Topic: emulsion slime on one side of screen after exposed/rinsed  (Read 6275 times)

Offline GaryG

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Re: emulsion slime on one side of screen after exposed/rinsed
« Reply #15 on: September 06, 2013, 12:41:07 AM »
A very basic "important" starting point is the mfg guidelines (little booklet in emulsion box)
to get a target time with which to start. They give factors that help save time, rather than
guess and waste time. It is the building block relating to the step wedge routine.


Offline Frog

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Re: emulsion slime on one side of screen after exposed/rinsed
« Reply #16 on: September 06, 2013, 12:56:13 AM »
A very basic "important" starting point is the mfg guidelines (little booklet in emulsion box)
to get a target time with which to start. They give factors that help save time, rather than
guess and waste time. It is the building block relating to the step wedge routine.

Yep, that's the starting point. If doing a manual step wedge test, I'd at the least check the range from half the suggested time to double it.
Gotta remember that the mfg does not know your actual EOM, or even the exact factor to figure with some dyed mesh.
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Offline mk162

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Re: emulsion slime on one side of screen after exposed/rinsed
« Reply #17 on: September 06, 2013, 08:23:59 AM »
a lot of emulsions have a wide exposure window, so it's nice to find one that works with the same time with all of your mesh counts.  Or at least most of them.

Offline Grumpy Ole Artist

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Re: emulsion slime on one side of screen after exposed/rinsed
« Reply #18 on: September 06, 2013, 11:24:11 AM »
Definitely, under-exposed! I have used Ulano's (diazo-sensitized) RLX for years...I have had COUNTLESS sales reps foist photopolymer samples on me over the years and have NEVER got a useable screen out of it! With our exposure unit, ( A glorified tanning bed with fluoro UV bulbs) and the fact that I am stuck in "Vellumopolis" with all of it's attendant weaknesses (Lack of image density, and a non-transparent carrier) I absolutely NEED the exposure latitude that Diazo emulsion affords. I use from 60 mesh up to 230, and times range from 20 minutes at the coarse end of the spectrum to about 3 minutes at the fine end. I can not begin to speculate HOW one could realize useable screens at one exposure time...Guess I need to get out more, LOL!
Up your time, and you'll be fine!
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