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Re: Exposure/washout units

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  • Gerald Lange
    Dear Tom Don t really know how to address the first issue. Economics is a big factor here. If you are not doing industry standard (and to do so requires
    Message 1 of 14 , Oct 3, 2001
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      Dear Tom

      Don't really know how to address the first issue. Economics is a big
      factor here. If you are not doing "industry standard" (and to do so
      requires owning variously expensive equipment; processing machine,
      bases, etc., all of which have their own uniquely varied
      requirements) you are doing "alt," and in alternative processing the
      techniques and materials employed are so varied, subjective, and
      discontinuous one to another that to speculate on their relative
      merits or demerits is foolhardy.

      I'd like to think this must be somewhat akin to the problems that
      Monotype must have faced. Now that they've potentially put a possible
      foundry into every printshop, how do they regulate it? Their answer
      seems to have been, to not regulate. Give the caster the ability to
      alter character positioning, metallurgy, type height, etc. Hmm, maybe
      not the best analogy after all.

      Maybe I can do better on machine washout. Well, the machine should
      fill up with water to some point just above the brushes. My rep says a
      quarter of an inch, and I believe every word he says. The machine has
      a cyclical pattern that seems to brush, halter, and brush again. It
      could be reversing the pattern, I do not know. The machine is closed
      during the process. The halting is only for a second or two. The
      machines are timed-set. It is initially a matter of trial and error to
      find the correct timing though there is certainly enough info out
      there to get you on the right track quite quickly. This of course
      various with different configurations of plates. Nothing but variables
      in photopolymer I'm afraid. Trick, I quess, is to find your own here.

      Regarding the checking. I never do this. I don't know what I could
      tell by what I was seeing anyway. This may probably be a good idea,
      whether you are doing this by machine (as Frank does) or by hand (as
      you are), but I assume you need the eye for it. If I've had problems
      (other than the purely mechanical) they have generally been in exposure
      because I have knowingly taken shortcuts, specifically, ganging plates
      or running different weights of text or formats together or, the worst,
      saying yes to the client who prefers to furnish their own plates. I do
      a certain amount of hand washing out for a specific kind of plate and
      I try to mimic what I believe are the actions of the machine. I have a
      little contraption built for this that I use in the machine, against the
      brushes; I think I may have mentioned this in a very early post. Personally,
      hand-washing scares the crap out of me. I do a lot of bookwork mainly so
      consistency is quite crucial to me. I'm under the opinion that seconds
      count here and I don't trust variables in regard to processing.

      Doubt if this answers or resolves anything. But it was a good question
      and, since no one else jumped at it, I thought it worth a shot.

      All best

      Gerald

      > Hello Gerald & others,
      > With such variations apparent in different plates, it would help my
      > perspective if you might label the brand or source of the various plate
      > materials you are describing. I am using Gene Becker's Miraclon MS152 pla=tes
      > in a home-made, handwashed system, getting good results (within a long
      > process of adjustments and fine tuning and experimenting). But I am
      > continually amazed at how divergent everyone's answers are: I hardly ever=
      > hear the same instructions, exposure times, washout times, proceedures, e=tc,
      > despite how certain and enthusiastic we all are about our results. I have=
      > projected the same certainty at times, only to realize later that I had
      > misinterpreted some factor or another. Correctly diagnosing problems in t=his
      > technology remains a humbling mystery, despite my being able to use it
      > successfully for numerous commercial and artistic projects.
      >
      > Another request: I wonder if someone might describe the machine washout. =Does
      > the machine fill up with water and soak before brushing? Or maybe pause
      > brushing and soak occasionally? For how long? Or is it all continuous act=ion?
      > And is there any method used for observing/evaluating the progress, or is= it
      > just a timed setting? In hand-washout, I am continually checking, and cho=ose
      > to halt early or continue washing down to clean metal backing according t=o
      > the specific details of the plate. I have wondered how this could be poss=ible
      > in the machine.
      >
      > Any rate, thanks for carrying on so -- I'm listening with interest.
      > Best wishes, Tom
      >
      > Tom Parson
      > Now It's Up To You Publications
      > 157 S. Logan, Denver CO 80209
      > (303) 777-8951
      > http://members.aol.com/typetom
    • Harold Kyle
      Tom, I had thought, much like you do, that hand-washing would be accurate than machine washing--until I recently switched over to a machine washout. I
      Message 2 of 14 , Oct 4, 2001
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        Tom,

        I had thought, much like you do, that hand-washing would be accurate
        than machine washing--until I recently switched over to a machine
        washout. I purchased the machine for better exposure and for
        convenience, but didn't anticipate better washout.

        In fact, the machine washout produces noticeably better plates. The
        main advantage to the machine is its evenness of pressure. You don't
        need to check the plate periodically for unwashed areas because the
        whole plate washes out at the same rate. Corners took notoriously
        long to wash out by hand; now, I don't have to worry about overdoing
        the washout in the center. This isn't such a problem on type, but a
        10% or 5% screen in the middle of your plate will suffer from
        excessive washout. Because its pressure is constant, it doesn't tend
        to wash away isolated dots as easily.

        Since the machine brushes are larger, they also get the plate out of
        the water sooner. Some plates, especially the large (say, 11x17)
        ones, had to remain underwater for 10+ minutes to wash out with a 4x8
        brush. Leaving them underwater so long can cause delamination of the
        plate. Oh, and the machine brushes don't have hard plastic corners
        that can scratch the surface of your plate.

        Handwashing works. Telling the difference between a machine washed
        plate and a hand washed plate (by someone who has excellent
        technique) would be impossible on most small plates. But for large
        plates or ones with isolated dots, light screens, or very small text,
        machine washing works much better.

        Harold Kyle
        www.boxcarpress.com
      • typetom@aol.com
        Thanks Gerald, Your description of the washout machine action is about as I imagined, having only seen one not in operation. My washout time is presently quite
        Message 3 of 14 , Oct 4, 2001
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          Thanks Gerald,
          Your description of the washout machine action is about as I imagined, having
          only seen one not in operation. My washout time is presently quite a bit
          longer than others have mentioned, perhaps because I use a very soft brush
          and only very gently agitate. Obviously still some room for experimentation
          here, but my results now are quite consistent and it seems possible to
          control it by hand washing.

          My first question was probably simpler than your answer: just that the plate
          references (such as MK or MLD) don't tell me much unless I am using the same
          source for plates, I think. Would the MK152 be the same as the MS152 I get
          from Gene Becker? Maybe I just need to go back to the various notes Gene gave
          me to see if the answer is there. Similarly, I have had some difficulty
          making comparison with materials supplied by NA Graphics, because the names
          differ. So I thought it might help if I say Gene Becker's Miraclon MS152
          rather than 152 or MS152....

          Regarding toxicity, it sounds like it's a question of skin sensitivity rather
          than poison or carcinogin. I have hand-washed maybe 40 sheets (A3 size,
          297x420 mm = 11x15? cut to innumerable smaller plates) over six years or so.
          No gloves. No noticable skin reaction, no other problems at all (except an
          occasional cut from the sharp edge of the metal backing, of course). I do
          keep the water running slightly (to keep the temperature constant) so maybe
          the concentration is low. Or maybe I'm just not sensitive. So far, it seems
          to me remarkably benign. The very slight odor from unexposed material also
          seems inconsequential to me. UV light, of course, is bad for the eyes (and
          skin as well, I think).

          Best regards, Tom

          Tom Parson
          Now It's Up To You Publications
          157 S. Logan, Denver CO 80209
          (303) 777-8951
          http://members.aol.com/typetom
        • Frank Cabral
          Hello Tom, The orbital washout unit has been the only way I have been able to produce consistently good plates efficiently. The time factor is very important.
          Message 4 of 14 , Oct 4, 2001
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            Hello Tom,
            The orbital washout unit has been the only way I have been able to produce
            consistently good plates efficiently. The time factor is very important.
            About twenty years ago, when the photo polymer was just entering the
            market, I was told by salesmen that the plate could be exposed in the sun
            and washed out in a sink with any brush. I spent what seemed and endless
            amount of time discovering only that there are many variables. I built
            things, converted things, nothing I did seemed to have the same results
            twice, or that the plates were just not good enough. I like process, but I
            was always off task trying to find a solution.
            While not quite a glorious epiphany, the machine allowed me to make
            accurate plates, in a short time with not so much guess work. I only had to
            pay attention to the orientation and density of the negative, the suction
            of the vacuum table, cleanliness of the kreene, monitor the wash out, water
            temperature, drying and final exposure to harden the material. The process
            is simple and consistent (generally).
            I like to examine the plate during washout to check that as much
            material has washed away as possible but not so much as to weaken its
            structural integrity , (small bits of the design, or letters that break off
            during printing that you don't notice until you are finished).
            Gerald has a good explanation of the washout process.
            I think Monotype had much more exacting details built into their
            production, and while success at times seems atmospheric the documentation
            they provided would allow you some success. There are just so many pieces
            to pull together and each one requires complete attention to detail.

            If you contact me off list I can send you some plate processing
            instructions for Miraclon/Rigilon, this is the MLD made by Toyoba. They
            also recommend it for crash printing, hot stamping and for pantograph
            masters. I have only used it for letterpress printing.

            Regards
            Frank
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