Formula for wetting agent
Xosni
regards
Xosni
Richard Knoppow
The MSDS for Photo Flo will give you some help. It contains two
surfactants, an ionic and a non-ionic one. One, at least is sold under
the trade name of Triton-X. I think you will find bulk chemicals to
make it harder to find than the wetting agent. In other words, I don't
think its practical to make it in small amounts.
If something like Photo Flo is not available where you are a very
weak solution of dishwashing detergent will do. Both the diswashing
detergent and Photo Flo work better if some Isopropyl alcohol is
added. Use about 25ml of alcohol per liter of working solution and use
the Photo Flo at half strength.
---
Richard Knoppow
Los Angeles, CA, USA.
dick...@ix.netcom.com
Dr. Dagor
phosphate and essentially the same as one half of the photoflow formula.
Compare to photo flow, it's also cheap. I use it on negs with pretty fair
success. Haven't tried it with prints though.
"Xosni" <xo...@gega.net> wrote in message
news:5cb2a3f0.02030...@posting.google.com...
Xosni
But doesn't Isopropyl alcohol etche up the film on the long run?
How much of detergent should I disolve?
regards
Xosni
Richard Knoppow
Isopropyl won't dissolve film base. Rubbing alcohol can be used if
there is nothing except alcohol and water in it.
Not much detergent is needed, a few drops per liter for working
solutions. Just enough is needed to keep the water from beading up on
the film surface. The combination of wetting agent and alcohol should
cause the surface water to flow rapidly off the film without leaving
droplets or streaks.
Mike King
their bottles of wetting agent (I finally had to break out the third 4 ounce
bottle from my hoard this year) since I only use a few drops of wetting
agent per roll in a final distilled water rinse, it has lasted me a long
time. I think it's bad practice and false economy to try to find cheaper
substitutes for wetting agents and stop baths when they cost only pocket
change per roll in the first place.
my two cents
darkroommike
"Dr. Dagor" <drd...@hotmail.com> wrote in message
news:kXVi8.20028$q2.1073@sccrnsc01...
Don Parker
I use Richard's recipe and it works very well. Thanks Richard. Don Parker.
Richard Knoppow
>xo...@gega.net (Xosni) wrote:
>
>>dick...@ix.netcom.com (Richard Knoppow) wrote in message news:<3c8bf54c....@nntp.ix.netcom.com>...
>>> xo...@gega.net (Xosni) wrote:
>>>
>>> >I need a formula for making wetting agent from scratch. Can anyone supply it?
>>> >
>>> >regards
>>> >Xosni
>>> The MSDS for Photo Flo will give you some help. It contains two
>>> surfactants, an ionic and a non-ionic one. One, at least is sold under
>>> the trade name of Triton-X. I think you will find bulk chemicals to
>>> make it harder to find than the wetting agent. In other words, I don't
>>> think its practical to make it in small amounts.
>>> If something like Photo Flo is not available where you are a very
>>> weak solution of dishwashing detergent will do. Both the diswashing
>>> detergent and Photo Flo work better if some Isopropyl alcohol is
>>> added. Use about 25ml of alcohol per liter of working solution and use
>>> the Photo Flo at half strength.
>>>
>>> ---
>>> Richard Knoppow
>>> Los Angeles, CA, USA.
>>> dick...@ix.netcom.com
>>
I took my own advise and looked again at the MSDS for Photo Flo.
Somewhere Kodak describes it as a mixture of an ionic and a non-ionic
wetting agent. However, the description in the MSDS is _exactly_ the
same as that for Triton-100-X, a concentrated surfactant. I haven't
checked on the amounts and prices of Triton 100 X but still suspect it
is not practical in the amounts used in practical photography. This
wetting agent is used in other places, for instance, its one of the
ingedients of Agfa Sistan, a stabilizer for silver images. I think the
main reason for its being there is that Sistan is used as a final
rinse for film and paper.
In any case, Kodak's MSDS are available from their web site at
http://www.kodak.com and both Kodak and many other MSDS are available
from http://hazard.com
Jean-David Beyer
>
> I need a formula for making wetting agent from scratch. Can anyone supply it?
>
But if you insist, you might try using the following kinds of chemicals:
alkalyne sykogirucubates
sulphonates of higher fatty alcohols (e.g., Alkanol, Igepon, Lorol,
Ocenol, Teepol)
saponin
purified ox gall, industrial bilary salts (you will not like these)
I use PhotoFlo myself.
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 3:15pm up 23 days, 4:43, 5 users, load average: 3.10, 3.09, 3.03
Bill Troop
>weak solution of dishwashing detergent will do.
I have always been too nervous to recommend or formulate a wetting
agent based on my present knowledge. One of the reasons I am
so cautious is because of LFA Mason's advice on page 45 of
Photographic Processing Chemistry (Focal, 2nd ed., 1975):
"Commercial detergents should not be used on account of the various
additives made to these products, *and their unknown photographic
properties* [emphasis supplied]. It is best to use one of the agents
packed specially for photographic purposes, but failing this only the
'pure unadulterated wetting agent should be employed. If the latter
course is adopted, care must be taken to ensure that the *purity is
such that no alkali insoluble material separates from the developer
after the addition of the wetting agent* [emphasis supplied].
References to chemicals here and in the literature refer to anionic and
ionic surfactants. But somehow I have the idea that the agent used
in the anti-fungal wetting agent I used to like from Tetenal (its name
escapes me at the moment) was cationic.
Two things bother me about homemade wetting agents: you really
want to be secure in the knowledge that the chemical has been
extensively tested for possible interaction with the material over
many decades, since it will remain on the material if it is used
just before drying; and second, that without special knowledge,
how can we know what grade (i.e. purity) of a given chemical
is required to do the job without having undesired side effects?
I really like the idea of an anti-fungal wetting agent, but that raises
further questions: if the anti-fungal agent is stable enough to last
for decades, and does not cause other harm to the film or paper,
how good can it possibly be for your skin when you flick it off
the material?
Richard Knoppow
I really have to agree with Bill. I should have mentioned in my post
that I recommend the dishwashing detergent only as a last resort.
The wetting agents used by Kodak and others are available but
probably in much larger quantities than any individual could ever use.
While Kodak Photo Flo shows two ingredients it turns out that both
are part of Triton 100 X, a wetting agent available from several
manufacturers. Photo Flo 1200 appears to be pure Triton 100 X. I have
no idea how much this stuff costs in bulk but would guess the minimum
quantity would be a lifetime supply for several thousand
photographers.
Bill Troop
> are part of Triton 100 X, a wetting agent available from several
> manufacturers. Photo Flo 1200 appears to be pure Triton 100 X. I have
> no idea how much this stuff costs in bulk but would guess the minimum
> quantity would be a lifetime supply for several thousand
> photographers.
Richard, you've got me curious about Triton 100 X. I did a google search,
and come up with all kinds of contradictory and worrisome information,
including that there are thought to be carcinogenic impurities in it, and
that it can solubilize proteins and may contain peroxide impurities. I would
be hesitant to use a generic form because I don't know two things: (a)
exactly what grade Kodak uses (it may be a custom-manufactured
grade) and (b) what other ingredients Photo-Flo contains, that might
not be listed in the MSDS. Honestly, I would think that somewhere there
has to be a better chemical. I would suppose that a chemist specializing in
surfactants could recommend something. After all, this product is probably
30 years old and there have been huge advances in the meantime. But even
if we found some great candidate, how could we be sure that it had no
effects
on photographic materials?
ele...@comcast.net
Reply-To: ele...@comcast.net
Richard Knoppow <dick...@ix.netcom.com> wrote:
<snip>
: While Kodak Photo Flo shows two ingredients it turns out that both
: are part of Triton 100 X, a wetting agent available from several
: manufacturers. Photo Flo 1200 appears to be pure Triton 100 X. I have
: no idea how much this stuff costs in bulk but would guess the minimum
: quantity would be a lifetime supply for several thousand
: photographers.
: ---
: Richard Knoppow
: Los Angeles, CA, USA.
: dick...@ix.netcom.com
A google search turned up http://www.chemistrystore.com/triton_x100.htm
1 quart $8.80
1 gallon $21.41
5 gallon $90.50
Ray
--
E. Ray Lemar ele...@comcast.net
Note: My former ele...@home.com email address is no longer valid.
Lloyd Erlick
For many years I have been using distilled water
straight, absolutely nothing in it, as a final rinse
for both film and paper.
I hang both film and paper to dry, and squirt the
distilled down both sides before leaving it in peace
(no squeegee). I never get any type of spots or
evidence of differential drying due to droplets on the
surface.
I have mainly used Ilford, Kodak and Agfa papers, but
my limited use of Forte and Bergger papers indicates
the same. (I am speaking of FB papers.) Present day
films (I use mostly Kodak T-Max film) seem close to
invulnerable. I believe distilled water is a key
darkroom material; wetting agents are not strictly
necessary.
regards,
--le
-------------------------------------
Lloyd Erlick,
357 Richmond Street West,
Toronto M5V 1X3 Canada.
---
voice 416-596-8751
ll...@the-wire.com
http://www.heylloyd.com
-------------------------------------
Bill Troop
> tension of water on a film. Triton 100 and alike (nonionic) are
> excellent in even low concetration. However, you can replace it with
> some lab grade ethanol (methylated spirits).
Why use methanol at 10% when it is known to be so potentially
problemmatical? LFA Mason (1974, p. 208) notes that "Prolonged
immersion [of 80:20 meths/water] should be avoided, as the plasticizer
may begin to be extracted from the base,, making it brittle." [such a
solution is a traditional method for rapid drying] In addition, I am
uncomfortable with your characterization of shampoos, dishwashing
liquid and car wash preparations as interchangeable. Shampoos are
primarily based on ammonium (less frequently sodium) lauryl sulfate;
dishwashing and laundry detergents are quite different in composition.
A photographic wetting agent should have low foaming properties,
some bactericidal and fungicidal properties, and should above all have
been tested on photographic materials. I accept Mason's comment
that "Commercial detergents should not be used on account of the various
additives made to these products, and their unknown photographic
properties." Mason recommends anionic compounds such as sodium
alkyl supohonates and sodium alkyl sulphates "where R is a long chain
alkyl group, which may contain cyclic substituents"; or "nonionic
compounds such as polyethyleneglycol derivatives, saponin, etc." He
however adds the warning that with these chemicals, "care must be taken
to ensure that the puity is such that no alkali insoluble material separates
from the developer on standing after the addition of the wetting agent",
referring to the case where wetting agents are added to the developer
for the "elimination of air bubbles, etc." He does not even mention
the use of wetting agents as a final step in the ordinary processing of
prints and films, interestingly. It is his raising of the purity bugaboo
that
gives me most concern. Isn't there some modern surfactant that would
accomplish all of these goals with a reasonable expectation that it would
not interfere with archival processing of photographic materials?
In the meantime, the only wetting agent I am comfortable using or
recommending is Photo-Flo, specifically as packaged by Kodak;
I also like Lloyd's suggestion just to use distilled water. Since streaking
and spotting problems that can arise when wetting agent is not used
are probably due to water impurities, distilled water appears to be the
safest and simplest method of dealing with the problem. I am also
uncomfortable about using formalin when there is any possible
alternative. I was frequently warned against the use of formalin by
Haist and H.D. Russell.
dr bob
purchasing a decent supply of commercially available wetting agent rather
than mess around with products that may or not work well at best and at
worse may affect one's work deleteriously. I have a lifetime (several
hundred lifetimes, probably) of Triton 100 X which I used eons ago to
produce special experimental electrodes in fuel cell research. I don't even
remember the manufacturer but it seems that they were a major company (Du
Pont, Union Carbide, or the like). The pure stuff is like syrup and diluted
to "operating" strength, goes a long, loooong way.
I have yet to use this material in my personal endeavors. I may do
some experimenting and relate the results later, It would seem more prudent
to me to use nothing than to substitute questionable products and home-made
concoctions, at least where negatives are concerned. OBTW we experienced
the dreaded :stick-build-up effect on certain plastic parts during our early
work with Triton 100 X. Hot water and a soak in a dilute solution of sodium
bi-carbonate removed most of it.
Truly, dr bob.
"Richard Knoppow" <dick...@ix.netcom.com> wrote in message
news:3c923fa8...@nntp.ix.netcom.com...
UrbanVoyeur
more uniform development AND in the case of T-max film, remove the purple
dye. Removing the purple mask can be important if you use multi contrast
paper.
J
"Lloyd Erlick" <ll...@the-wire.com> wrote in message
news:3c932839...@news.the-wire.com...
Jean-David Beyer
>
> Common sense indicates that one would save money in the long run by
> purchasing a decent supply of commercially available wetting agent rather
> than mess around with products that may or not work well at best and at
> worse may affect one's work deleteriously. I have a lifetime (several
> hundred lifetimes, probably) of Triton 100 X which I used eons ago to
> produce special experimental electrodes in fuel cell research. I don't even
> remember the manufacturer but it seems that they were a major company (Du
> Pont, Union Carbide, or the like). The pure stuff is like syrup and diluted
> to "operating" strength, goes a long, loooong way.
I suppose Kodak's FotoFlo 600 (the usual retail stuff is FotoFlo 200) or
FotoFlo 2100 would last longer too. I find a pint of FotoFlo 200 lasts a
very long time. Unless you are a large commercial processor, why bother
with anything else? The only problems I have ever had with it came when
I first started and they said to use a capful in a specified amount of
water. That was always too much, so I bought a 5ml graduate and mix the
stuff to 80% of recommended strength in distilled water and have never
had any trouble since.
Are we not making too much of this? When all is said and done, more is
said than done. ;-)
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 1:50pm up 26 days, 3:18, 3 users, load average: 3.00, 2.97, 2.92
Bill Troop
> Mason writes about 80:20 methylated spirits water, while I use 10:90.
> He uses it for rapid drying, I add some ethanol to reduce surface
> tension. He soaks it for 5 minutes to let it inside the emulsion, I
> recommend few seconds to wet the surface.
Ok. Yes, there is a difference between soaking for five minutes, and yes
there is a difference between 80:20 and 10:90. But it has been clearly
illustrated that this chemical can harm film. How can we tell that a brief
immersion in a highly diluted solution will not cause a process to begin
which over time will harm the film? If long immersion produces noticeable
loss of plasticizer, it is possible that short immersion will produce a
subliminal loss of plasticizer (or something else) that will eventually
cause more rapid deterioration of the film over time.
> are you by chance familiar with formulation of shampoos, dishwashing
> liquids, etc?
I have formulated shampoos and have a little awareness of the kinds
of chemicals typically used in them; and I was a friend of the late Dr.
Florence Wall, who was involved in the formulation of the first detergent
shampoos used in America -- P&G's Drene, in 1934. (Drene, incidentally, was
used
on the on the interior surface of the windshield of 'Glamorous Glennis'
during Chuck Yaeger's first supersonic flight in 1947, to prevent frost
formation.) (Yet more trivia: Edgar Cayce approved of Drene!) The primary
chemical used was 'Turkey Red Oil', or sulphonated castor oil, if I recall
correctly.
> As a rule of thumb, the cheaper the
> product, the bigger chance to get better results.
That's a good point. I wouldn't think that the low molecular weight protein
hydrolysates in some posher shampoos would be beneficial to film.
> And in my experience, that anti-foaming stuff was creating more
> problems than solving.
My point was not to use an anti-foaming agent (one more item to test) but to
choose an agent that intrinsically has low foaming properties. One of the
problems with shampoo is that typically, the primary surfactant, which
does all the work, does not have high foaming properties. But the user
does not think he or she is getting clean unless there is much foam. For
this reason, secondary surfactants and other agents are added to shampoos
to increase foam, which makes them undesirable for photographic purposes.
The same principle applies to dishwashing detergents, but not to laundry
detergents, where low foaming is desired. Not that I would use laundry
detergent on my film!
> >some bactericidal and fungicidal properties, and should above all have
> >been tested on photographic materials.
>
> formaline is used for the purpose,
Everyone at Kodak advised me against the use of formalin; it has some
deleterious effect on image stability, although I forget the details at this
time. For this reason, Kodak processes use glutaraldehyde or
succinaldehyde (typically in the form succinaldehyde bis bisulfite).
You point out that these chemicals may be more dangerous for
humans to handle, but it seems they are much better for the
photographic material. Because succinaldehyde is so expensive,
I only recommend glutaraldehyde in alkaline hardening processes.
The disadvantage of glutaraldehyde is that it does not last more
than a week or so in solution; succinaldehyde is usable for longer
periods.
> The best advice to avoid fungi is - keep it dry.
That's not much help when you live in a humid environment!
> >I accept Mason's comment
> >that "Commercial detergents should not be used on account of the various
> >additives made to these products, and their unknown photographic
> >properties.
>
> Instead of speculation, I prefer an experiment. Try it.
In principle you are correct, but practically, who has the resources to
conduct extensive accelerated aging tests? The hideous problems
that surround microfilm deterioration show just how difficult it was for
Kodak, a major company at the height of its chemical expertise (let us say
from 1950 to 1980), to get things right.
> >" Mason recommends anionic compounds such as sodium
> >alkyl supohonates and sodium alkyl sulphates "where R is a long chain
> >alkyl group, which may contain cyclic substituents"; or "nonionic
> >compounds such as polyethyleneglycol derivatives, saponin, etc.
>
> and this is exactly stuff you'll find in most of shampoos, Palmolive
> dishwashing liquids etc.
I wish you wouldn't suggest an equivalence between dishwashing liquids
and shampoos. Shampoos are unique formulations. Very, very seldom
is the primary surfactant not sodium or ammonium lauryl sulfate.They
are much milder than other detergent products, and unfortunately
from the photographic point of view, are intended to accomplish
all kinds of things beyond mere wetting. Even the cheapest shampoos
today may contain low molecular weight proteins which should easily
penetrate into photographic materials, and which have humectant
properties. The humectant properties of the shampoo might help
cause fungus growth, don't you think? In addition, other humectant
agents are often present in shampoos, hand cleansers, and dishwashing
agents intended to help 'moisturize' the skin. I would think that any
of these agents might help in the growth of fungus, by providing even
a small basis for moisture attraction.
>The problem here, sometimes the manufacturer
> adds plenty of sodium chloride (common salt) or sodium sulfate to make
> it look viscous, while the surfactant content is being kept to the
> minimum. To save money. Again, it varies from brand to brand. For
> example Palmolive hand wash thing contains three sufactants, common
> salt, sea salt, plus few more compounds, plus formaline, plus
> anti-bacterials. If you can wash your hands in it, you should not be
> worried.
As you note, the need for viscosity control adds a whole new layer
of complexity to these products, none of which is desirable in a product
used for film. I would not want traces of any of these products on my
film.
> Droplets of pure water may dry at different rate than the rest of a
> film, you may experience crater-like pattern on the film. For that
> reason I use 10% ethanol (methylated spirits).
Another good point. Again, though, differential rates in drying
is still going to occur naturally, and more particularly in the
case of tanned film where the tanned parts dry at a
different rate from the untanned parts, giving rise to some
potentially valuable adjacency effects.
> Some use even use glutar aldehyde, which is much nastier.
My point is that it is better for the photographic material than
formalin.
> And we happily live 70-80 years.
Isn't it amazing? Haist remarked to me recently that he never expected to
live so long, given the many exposures to toxic chemicals he has had.
He has theorized that sublethal exposures to toxins may stimulate the
immune system.
>Do you know that
> furaldehyde, the compound responsible for that nice smell of a freshly
> baked bread crust, is considered toxic (suspect cancerogen)?
That's an interesting point. I know that it is formed naturally upon the
thermal decomposition of carbohydrates, but to what extent is it
now used as an additive? I remember reading that the UK had
withdrawn its use as a food additive.
> You are worried without reason. Just follow common sense, don't eat
> and drink your photo stuff, ventilate your workplace, wash your hands
> after. Follow simple lab rules, use gloves if required. Painting with
> modern paints is more dangerous than processing your Tri-X or
> Ektachrome. Filling your car tank with a gas is more dangerous than
> photographic processing. Many gardening chemicals are highly toxic,
> but still we enjoy our gardening.
Aw, leave me to my worrying. As Thomas Wolfe is said to have
observed, 'Even paranoids have enemies.'
P.S. And speaking of gardening toxins, my fungicide of choice is sulfur
powder,
which appears to be the safest of all fungicides, and also functions as a
miticide.
But Ortho has withdrawn its product. Do you know where I can obtain
an equivalent grade cheaply? A few years ago I was curious about the grade
of sulfur that Ortho was using -- I wondered if it was safe to use for
cosmetic
purposes. An Ortho chemist I talked to told me that as far as he knew, the
only
impurity was sodium carbonate. I think Safer has a ridiculously expensive
sulfur spray, and the nasty liquid form (I forget the name -- liver of
sulfur?)
is widely used as a pet fungicide. I want the plain powder, cheap, and in
reasonably pure form -- let's say, pharmceutical grade.
Robert Goodman
> I need a formula for making wetting agent from scratch. Can anyone supply it?
What does "from scratch" mean? What types of materials are you
confined to starting with?
Do you mean something like synthesizing dioctyl sodium sulfosuccinate
from maleic anhydride, octanol, and sodium sulfite? Or an alkyl
ethoxylate from a fatty (or similar) alcohol and ethylene oxide?
Or do you mean something like the way I make my bubble bath from
scratch by mixing already-made surfactants? --
http://users.bestweb.net/~robgood/lather.html
Robert
Robert Goodman
> > While Kodak Photo Flo shows two ingredients it turns out that both
> > are part of Triton 100 X, a wetting agent available from several
> > manufacturers. Photo Flo 1200 appears to be pure Triton 100 X. I have
> > no idea how much this stuff costs in bulk but would guess the minimum
> > quantity would be a lifetime supply for several thousand
> > photographers.
>
> Richard, you've got me curious about Triton 100 X. I did a google search,
> and come up with all kinds of contradictory and worrisome information,
> including that there are thought to be carcinogenic impurities in it, and
> that it can solubilize proteins and may contain peroxide impurities.
If you're referring to Triton X-100, a substance I have quite a bit of
familiarity with from use in biochemistry, I can assure you that its
"carcinogenic impurities" are no worse than the run of the mill
products of ethoxylation commonly found in shampoos, for instance.
Ditto for the peroxide impurities. If 1,4-dioxane and similar
contaminants really are a danger (as opposed to a passing scare), then
you should be aware that it's probably on your eating utensils if you
use dishwashing liquid.
Triton X-100 comes in for use when you want to solubilize lipids while
being GENTLE to proteins. However, Triton X-100 and similar products
(nonoxynols (as in spermicide), Shaklee Basic-H, others) can
anesthetize mucous membranes (such as the cornea), so take care when
using them.
Robert
Lloyd Erlick
>> Droplets of pure water may dry at different rate than the rest of a
>> film, you may experience crater-like pattern on the film. For that
>> reason I use 10% ethanol (methylated spirits).
>
>Another good point. Again, though, differential rates in drying
>is still going to occur naturally, and more particularly in the
>case of tanned film where the tanned parts dry at a
>different rate from the untanned parts, giving rise to some
>potentially valuable adjacency effects.
mar1802 from Lloyd Erlick,
I have never experienced any such cratering on films I
have used. Certainly Kodak T-Max films (I've processed
thousands of rolls of TMY in 120 format over the years)
have never done this for me. I've used limited numbers
of Agfa APX 400 films over the years, too, and never
seen any such thing.
I've never seen any such effect on any type of FB print
material either.
I think modern production of commonly used
photosensitive materials precludes this effect. No
doubt there are specialized materials that may show it.
Lloyd Erlick
>Are we not making too much of this? When all is said and done, more is
>said than done. ;-)
> .~. Jean-David Beyer Registered Linux User 85642.
> /V\ Registered Machine 73926.
>/( )\ Shrewsbury, New Jersey http://counter.li.org
>^^-^^ 1:50pm up 26 days, 3:18, 3 users, load average: 3.00, 2.97, 2.92
mar1802 from Lloyd Erlick,
I certainly think so, especially given the relatively
low cost of a pint of Kodak Phot-flo.
I also think anyone using Photo-flo who tries working
without it will notice no difference whatever if they
are using distilled water.
Personally, I hate the smell of Photo-flo. But I'm a
self-confessed weirdo on this subject, so don't mind
me. Adding alcohol to my final rinse water means
evaporating alcohol in my darkroom. That's just more
smell to me...
(Yes, I have a cat-box. And a nineteen year old cat who
is less than dainty these days. I use selenium toner,
too. No one is perfect.)
Robert Goodman
I stongly doubt it was that. It'd've been too low foaming (see
below). My guess would be SDS, or possibly a primary/secondary alkane
sulfonate.
> That's a good point. I wouldn't think that the low molecular weight protein
> hydrolysates in some posher shampoos would be beneficial to film.
>
> > And in my experience, that anti-foaming stuff was creating more
> > problems than solving.
>
> My point was not to use an anti-foaming agent (one more item to test) but to
> choose an agent that intrinsically has low foaming properties. One of the
> problems with shampoo is that typically, the primary surfactant, which
> does all the work, does not have high foaming properties. But the user
> does not think he or she is getting clean unless there is much foam. For
But you do need SOME foam in a shampoo, else it'd all run off the
head. Therefore you couldn't use a specifically low-foaming
formulation.
Usually the primary surfactant is high foaming enough, but they
typically boost it more, unnecessarily, and that makes it harder to
rinse.
No, actually both shampoos and hand dishwashing liquids typically
contain alkyl oligo-ethoxy sulfates as a considerable ingredient,
often the primary surfactant, because they're milder than the direct
alcohol sulfate.
> Even the cheapest shampoos
> today may contain low molecular weight proteins
No, the cheapest such products won't have complete or fragmentary
proteins.
Mike King
that did not use "air knives" to blow droplets off the film before the film
entered the dryers. It's not a pretty sight and re-washing and air drying
doesn't always repair the damage.
--
darkroommike
"Lloyd Erlick" <ll...@the-wire.com> wrote in message
news:3c95812a...@news.the-wire.com...
spamnot Richard Knoppow
What can happen is that the differential shrinkage of the emulsion
in the vicinity of a droplet can leave a ring of embedded mineral (if
there is any in the water) and can sometimes leave a ring of
distortion of the emulsion. Most modern emulsions are pretty hard but
are still swelled by wetting so the effect can happen.
The use of a final rinse with a wetting agent will prevent the
effect. So will the use of a swueegee but this presents the risk of
scratching the film. Even hardened film emulsion is still pretty soft
right after washing.
The hardness of emulsion is really a measure of its melting
temperature. Color films are hardened in manufacture to withstand
processing at 100F. A few B&W films seem also to be hardened to this
point, but many older films are not so hardened (Tri-X being
notorious) and can present difficulties if subjected to higher than
normal processing temperatures or to much mechanical stress while wet.
Once dry, the emulsion shrinks and is once again fairly hard
mechanically.
Richard Knoppow
Since distilled water has surface tension, and since surface tension
is the culprit, I can't see what difference that makes other than not
having anything to leave behind as a deposit. The differential drying
aroudn the droplets can still cause problems fi the film is not
squeegeed or a wetting agent is not used.
I've been using Michael Gudzinowicz suggestion of half strength
photo flo with some Isopropyl alcohol added and it works like a charm.