Re: reporting back: vinager and water on polymer plates
- gerald, thanks again for an in depth response,
now, as for the printer's alcohol, the little that i remember (it means "really little")
from a chem class from years back, alcohol won't stay 1% water as soon as it's
exposed to moisture??? ie, is there a special way to keep it away from moisture while
maintaining the convenience and ease of its application? or would it make no
noticeable difference with respect to the polymers (with a greater concentration of
water in the solution)?
one nice local letterpress man has told us recently in his elaborate multi hour lectures
that there are two types of photo polymer plates, one that is washed by water and the
other by alcohol. i've always knew of the water version. is alcohol version still
susceptible to degradation by water like the water washed ones?
--- In PPLetterpress@yahoogroups.com, "Gerald Lange" <bieler@w...> wrote:
> Any "quick drying" solvent, formulated as a plate wash or type wash,or
> even similar materials, such as pure printer's alcohol (1% water),
> will work. After I wipe plates, I immediately spray them with
> compressed air to additionally dry them out and get rid of any
> particulate matter (from the rag and accumulated paper lint).
> Press washes, and other slow drying solvents, should not be used to
> wipe "printing surfaces" (plates or type) as they leave an oily
> residue that will interfere with subsequent ink laydown.
> Most sheet photopolymer intended for letterpress is water-soluable.
> Don't know how useful experiments with soaking plates in liguids are.
> With any kind of solvent that contains water, you will probably see
> some kind of disintegration of the material.
> > a while back i asked about the compatibilities of blanket wash and
> polymer plates
> > we use - as my understanding was the polymers we use were water
> washed (as
> > opposed to alcohol?) and the wash was "aqueous" naphtha. the was was
> > recommended to us by other letterpress shop and a reputable local
> (and nationwide?)
> > ink supplier. of the replies, no one objected, i believe. any how,
> i accidently left the
> > wash on one polymer one overnight and it ate away. (oops.)... but
> what about the
> > effect of them on daily cleanup?
> > with respect to vinegar vs water on how they would breakdown the
> polymer, from a
> > little dunking experiment yesterday, the results were about the same
> in the period of
> > about 20 min or so - with respect to how they would crumble with
> pressure. so it
> > looks like it's the water, not the acetic acid that's affecting?
> > will a second (and multiple) dried polymer regain its original specs?
> > thanks again for help,
> > hiroshi
> > [vinegar, vegetable oil, water, photo polymer plate, blanket wash,
> water based, how to
> > clean]
Don't know about the hydration. I buy IPA 99 (99% Pure Isopropyl
Alcohol) made by Hurst Graphics, distributed in LA by KellyPaper,
among others. I only use it for post-printing purposes though. Don't
actually use it for cleaning plates. KellyPaper also sells Alcohol
Substitute (ingredients: 100% water) for about $10 a gallon. :-)
At any rate, if the alcohol is in a solvent can, I suspect it will not
draw as much water as your chem class might have indicated.
Your nice local letterpress man is correct about the two different
kinds of photopolymer. Most sheet photopolymer (as used in letterpress
purposes) is water-washout. But more and more, even flexographic sheet
photopolymer is water-washout. I can process flexographic plates
(water-washout) in my processor simply by increasing the bath
temperature and using water from a soft water conditioner. More of a
market there than there is for letterpress!!! Liguid photopolymer
and/or solvent-washout photopolymer are slowly becoming a thing of the
> gerald, thanks again for an in depth response,means "really little")
> now, as for the printer's alcohol, the little that i remember (it
> from a chem class from years back, alcohol won't stay 1% water assoon as it's
> exposed to moisture??? ie, is there a special way to keep it awayfrom moisture while
> maintaining the convenience and ease of its application? or would itmake no
> noticeable difference with respect to the polymers (with a greaterconcentration of
> water in the solution)?multi hour lectures
> one nice local letterpress man has told us recently in his elaborate
> that there are two types of photo polymer plates, one that is washedby water and the
> other by alcohol. i've always knew of the water version. is alcoholversion still
> susceptible to degradation by water like the water washed ones?