Musings on washing fiber-based prints

Nicholas O. Lindan wrote:

OTOH: Of the photographs that survive it seems the more mundane they
are the more valuable they are at providing a true record. There are
many websites devoted to 'found photographs' and I find them to be
far more interesting than websites full of spectacular desert sunrises
and mountain vistas. If they had all faded after 10 years something
important would have been lost.


Take a look at the back of the most recent National Geographic Magazine
for a photo of the Capitol Building? while the roof was being replaced.
Compare the scene then to now and that previously unpublished photo
becomes something of a treaure.

cheers

--
regards from ::

John Bartley
43 Norway Spruce Street
Stittsville, Ontario
Canada, K2S1P5

( If you slow down it takes longer
- does that apply to life also?)

Nicholas O. Lindan wrote:

OTOH: Of the photographs that survive it seems the more mundane they
are the more valuable they are at providing a true record. There are
many websites devoted to 'found photographs' and I find them to be
far more interesting than websites full of spectacular desert sunrises
and mountain vistas. If they had all faded after 10 years something
important would have been lost.


Take a look at the back of the most recent National Geographic Magazine
for a photo of the Capitol Building? while the roof was being replaced.
Compare the scene then to now and that previously unpublished photo
becomes something of a treaure.

cheers

--
regards from ::

John Bartley
43 Norway Spruce Street
Stittsville, Ontario
Canada, K2S1P5

( If you slow down it takes longer
- does that apply to life also?)

Scott Schuckert wrote:

In article , David Nebenzahl
wrote:

So, as most of us know, one of the big problems with FB is washing. And one of
the things that turns me off of using it is the enormous quantity of water
normally needed for adequate washing.

I'm an old-timer, so the vast bulk of paper I've processed was FB.
Washing is basically a process of dilution, so any trace of hypo at all
in the washwater will greatly slow the washing process. This is why the
tray washing someone else proposed is a less-than-ideal solution. While
I don't doubt "filtration" could be done, It's almost surely
impractical.

Tray washing is slower, since one is not removing
water continually at the print surface but instead
manually changing water periodically. But can be
just as efficacious and does save water (an advantage
if one is on well water.) Soak time plus several
changes of water is a good way of washing prints,
albiet more laborious. This is because washing is a
process of (1) diffusion, and (2) ion exchange, meaning
as thiosulfate and silver-thiosulfate complexes leave
the emulsion/paper fibers they saturate the wash water
until an equilibrium is reached between the thiosulfate
remaining in the print and the thiosulfate in the water
(i.e., washing slows down.) So the efficiency depends
on how often you change the water in the soak tray but
in the end the efficaciousness is the same as using an
archival washer.

Whether you could filter out the thiosulfate and complexes
adequately to recirculate and reuse the same wash water
I don't know; might be more expense than the water. But I
would look at reverse osmosis/purification systems (i.e.
demineralization). A water purification expert might be
to answer that, but you's also might want to add some
salts back into the water.


You'd probably have to manufacture, pay for (and then dispose of!) an
exchange resin of some kind. I used to extract silver from the fixer,
but silver is a lot more valuable than what you're trying to extract!
Good old water, on the other hand, is relatively cheap and a renewable
resource.

Just wash the darned stuff, using lots of fresh water.

Scott Schuckert wrote:

In article , David Nebenzahl
wrote:

So, as most of us know, one of the big problems with FB is washing. And one of
the things that turns me off of using it is the enormous quantity of water
normally needed for adequate washing.

I'm an old-timer, so the vast bulk of paper I've processed was FB.
Washing is basically a process of dilution, so any trace of hypo at all
in the washwater will greatly slow the washing process. This is why the
tray washing someone else proposed is a less-than-ideal solution. While
I don't doubt "filtration" could be done, It's almost surely
impractical.

Tray washing is slower, since one is not removing
water continually at the print surface but instead
manually changing water periodically. But can be
just as efficacious and does save water (an advantage
if one is on well water.) Soak time plus several
changes of water is a good way of washing prints,
albiet more laborious. This is because washing is a
process of (1) diffusion, and (2) ion exchange, meaning
as thiosulfate and silver-thiosulfate complexes leave
the emulsion/paper fibers they saturate the wash water
until an equilibrium is reached between the thiosulfate
remaining in the print and the thiosulfate in the water
(i.e., washing slows down.) So the efficiency depends
on how often you change the water in the soak tray but
in the end the efficaciousness is the same as using an
archival washer.

Whether you could filter out the thiosulfate and complexes
adequately to recirculate and reuse the same wash water
I don't know; might be more expense than the water. But I
would look at reverse osmosis/purification systems (i.e.
demineralization). A water purification expert might be
to answer that, but you's also might want to add some
salts back into the water.


You'd probably have to manufacture, pay for (and then dispose of!) an
exchange resin of some kind. I used to extract silver from the fixer,
but silver is a lot more valuable than what you're trying to extract!
Good old water, on the other hand, is relatively cheap and a renewable
resource.

Just wash the darned stuff, using lots of fresh water.

Tom Phillips wrote:

Jean-David Beyer wrote:

Tom Phillips wrote (in part):

Most hard water (at least in cities) is probably
softened to some degree anyway.

I do not know about that. I do know that some cities deliberately harden
the water a little so the lead used to solder copper pipes does not come
out in solution and poison their customers.

BTW, one can soften only a percentage of the water,
as I understand. I.e., you don't have to replace all
the calcium/magnesium, only a part of it so if you
have very hard water you could soften only by 50%.
A bypass system should let you do this.

Well when water is softened is doesn't necessarily
harm pipes or soldering. What softening water does
is replace naturally occuring calcium and magnesium
in the water with either sodium or potassium chloride
(via ion exchange.) So not only shouldn't it make any
difference when washing, it shouldn't harm pipes.

I suppose whether a municiple system softens water
depends on the degree of hardness. Where I live the
water's considered moderately hard (80-120 mg/L)
But even that leaves deposits on the faucets etc.,
so I consider it "hard." Hard water is officially
over 120 mg calcium/magnesium concentration per liter.

What can harm pipes is purifying water (demineralizing
through reverse osmosis.) This would also affect washing
prints if HCA isn't first used.

Presumably newer solders do not contain lead, but if they contain cadmium,
bismuth, etc., I would not want that in my water either.

Probably most plumbing system older than 40 years
have lead solder. It's advisable to run your tap
a few minutes before drinking to clear the standing
water in the pipes (which is what would contain
the lead.) Seriously doubt the minute amounts from
a few welds would affect photo procesing.

Tom Phillips wrote:

Jean-David Beyer wrote:

Tom Phillips wrote (in part):

Most hard water (at least in cities) is probably
softened to some degree anyway.

I do not know about that. I do know that some cities deliberately harden
the water a little so the lead used to solder copper pipes does not come
out in solution and poison their customers.

BTW, one can soften only a percentage of the water,
as I understand. I.e., you don't have to replace all
the calcium/magnesium, only a part of it so if you
have very hard water you could soften only by 50%.
A bypass system should let you do this.

Well when water is softened is doesn't necessarily
harm pipes or soldering. What softening water does
is replace naturally occuring calcium and magnesium
in the water with either sodium or potassium chloride
(via ion exchange.) So not only shouldn't it make any
difference when washing, it shouldn't harm pipes.

I suppose whether a municiple system softens water
depends on the degree of hardness. Where I live the
water's considered moderately hard (80-120 mg/L)
But even that leaves deposits on the faucets etc.,
so I consider it "hard." Hard water is officially
over 120 mg calcium/magnesium concentration per liter.

What can harm pipes is purifying water (demineralizing
through reverse osmosis.) This would also affect washing
prints if HCA isn't first used.

Presumably newer solders do not contain lead, but if they contain cadmium,
bismuth, etc., I would not want that in my water either.

Probably most plumbing system older than 40 years
have lead solder. It's advisable to run your tap
a few minutes before drinking to clear the standing
water in the pipes (which is what would contain
the lead.) Seriously doubt the minute amounts from
a few welds would affect photo procesing.

Tom Phillips wrote:

BTW, one can soften only a percentage of the water,
as I understand. I.e., you don't have to replace all
the calcium/magnesium, only a part of it so if you
have very hard water you could soften only by 50%.
A bypass system should let you do this.

When I was a kid in Kansas, which has very hard water due to the lime
stone, we had a water softener for a time. It was inline with the water
heater, so only hot water was softened.

The theory being that the primary reason for softening is to facilitate
washing with soap, which usually happens with warm water.

The company that put in the softener instructed us not to drink the hot
water, because of the salt content.

Bob

Tom Phillips wrote:

BTW, one can soften only a percentage of the water,
as I understand. I.e., you don't have to replace all
the calcium/magnesium, only a part of it so if you
have very hard water you could soften only by 50%.
A bypass system should let you do this.

When I was a kid in Kansas, which has very hard water due to the lime
stone, we had a water softener for a time. It was inline with the water
heater, so only hot water was softened.

The theory being that the primary reason for softening is to facilitate
washing with soap, which usually happens with warm water.

The company that put in the softener instructed us not to drink the hot
water, because of the salt content.

Bob

Water conservation might be "bull****" where you live, although I doubt
it, but in most of the world it is certainly not bull****. I agree,
water can be recycled, but is it being recycled?

Mark

Water conservation might be "bull****" where you live, although I doubt
it, but in most of the world it is certainly not bull****. I agree,
water can be recycled, but is it being recycled?

Mark