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#11
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On 2/28/2005 12:50 PM Claudio Bonavolta spake thus:
David Nebenzahl a écrit: Just wondering, dreaming of the day I might actually try to make prints on "real" (i.e., fiber-based as opposed to RC) paper ... 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. So ... how about if a guy were to build some kind of recirculator, complete with filtration? Maybe a big (5-10 gal.) tank with some kind of filter, like activated charcoal? Would such a filter be capable of removing enough residual hypo to be worthwhile? That way you could wash with a reasonable amount of water, using a small pump to circulate the water through the print washer and filter. The filter's the main thing I need help with, being relatively filter-illiterate. What do the chemist types here say? (I'm already assuming a thorough hypo-clearing bath before washing.) Or has someone already thunk this up and they're available for $29.95 at B&H? Available at B&H for $29.95 certainly not but (advanced) aquariophiles use reverse osmosis filters for their fragile fish: http://www.hydrationtech.com/Osmosis...r31703doc3.pdf Still not sure this will filter out fixer. Not sure it's a good idea unless you live in the Sahara ... Unfortunately no: from the white paper: "Osmotic filters are unlike other filters in that they produce a nutrient drink rather than simple water. This makes osmotic filters inappropriate for producing cooking or hygiene water ..." This system uses a "syrup" and osmosis to produce a safe drink from any kind of water, including brackish or muddy water. Looks like pretty good stuff for backpackers, though. -- "I know I will go to hell, because I pardoned Richard Nixon." - Former President Gerald Ford to his golf partners, as related by the late Hunter S. Thompson |
#12
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David Nebenzahl a écrit :
Unfortunately no: from the white paper: "Osmotic filters are unlike other filters in that they produce a nutrient drink rather than simple water. This makes osmotic filters inappropriate for producing cooking or hygiene water ..." This system uses a "syrup" and osmosis to produce a safe drink from any kind of water, including brackish or muddy water. Looks like pretty good stuff for backpackers, though. You're right David: not the best example ... Some other links, probably better: http://www.gewater.com/library/tp/833_What_Is.jsp http://members.tripod.com/%7Eurila/ and a search on Google with _reverse osmosis_ will take back dozens of other sites (often manufacturers) ... Not really practical anyway ... -- Claudio Bonavolta http://www.bonavolta.ch |
#13
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David Nebenzahl a écrit :
Unfortunately no: from the white paper: "Osmotic filters are unlike other filters in that they produce a nutrient drink rather than simple water. This makes osmotic filters inappropriate for producing cooking or hygiene water ..." This system uses a "syrup" and osmosis to produce a safe drink from any kind of water, including brackish or muddy water. Looks like pretty good stuff for backpackers, though. You're right David: not the best example ... Some other links, probably better: http://www.gewater.com/library/tp/833_What_Is.jsp http://members.tripod.com/%7Eurila/ and a search on Google with _reverse osmosis_ will take back dozens of other sites (often manufacturers) ... Not really practical anyway ... -- Claudio Bonavolta http://www.bonavolta.ch |
#14
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David Nebenzahl wrote:
I'm already assuming a thorough hypo-clearing bath before washing. And I think likely assuming a slot type archival washer. I think that if you could wash clean in fifteen minutes with very little water, what ever the method, rotary, tray circulation, still water diffusion, tray and agitation, or slot washer, a slot ARCHIVAL washer would be your choice. Apart from Mr. Knoppow's references to Kodak's reports of three minutes in hca being about all the good that can come from hca, I've read a post or two where ten or twenty minutes will reduce wash times considerably. Mr. Miniter tested an alkaline fix which gave clean results in ten minutes with constant agitation. My point is that pre-wash research is needed. It's the fix that needs to be washed out. That's the place to start. I'm using A. Thiosulfate at 1:49 for prints and think doing so may be a good prelude to the still water diffusions to follow. Dan |
#15
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"David Nebenzahl" wrote in message
... So ... how about if a guy were to build some kind of recirculator, complete with filtration? Maybe a big (5-10 gal.) tank with some kind of filter [...] That's an interesting idea. Before we get too far into this, let's consider the water first; you do not want softened water for the primary wash. |
#16
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"David Nebenzahl" wrote in message
... So ... how about if a guy were to build some kind of recirculator, complete with filtration? Maybe a big (5-10 gal.) tank with some kind of filter [...] That's an interesting idea. Before we get too far into this, let's consider the water first; you do not want softened water for the primary wash. |
#17
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jjs wrote:
That's an interesting idea. Before we get too far into this, let's consider the water first; you do not want softened water for the primary wash. Why not? -Peter www.desmidt.net |
#18
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On 3/1/2005 5:45 AM jjs spake thus:
"David Nebenzahl" wrote in message ... So ... how about if a guy were to build some kind of recirculator, complete with filtration? Maybe a big (5-10 gal.) tank with some kind of filter [...] That's an interesting idea. Before we get too far into this, let's consider the water first; you do not want softened water for the primary wash. OK, I'll bite; why? In any case, not an issue, as I don't have softened water. Just regular stuff (EBMUD, from reservoirs in N. California). -- "I know I will go to hell, because I pardoned Richard Nixon." - Former President Gerald Ford to his golf partners, as related by the late Hunter S. Thompson |
#19
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"Peter De Smidt" pdesmidt*no*spam*@tds.*net* wrote in message
... jjs wrote: That's an interesting idea. Before we get too far into this, let's consider the water first; you do not want softened water for the primary wash. Why not? Because softened water lacks the minerals that remove hypo/fix. I'm surprised that people don't know that. |
#20
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jjs wrote:
Because softened water lacks the minerals that remove hypo/fix. I'm surprised that people don't know that. I don't think it's so simple. In fact there's just been a technical discussion on this on the Pure-Silver mailing list. While it's true that, for example, sea water will wash photographic materials faster than demineralized water when a wash aid isn't used, it's not clear that there's any advantage to using mineralized water after a wash aid. Morever, softened water isn't de-mineralized. The mineral makeup is changed to something less likely to cause build up and hard water stains. I forget the exact details. Finally, it's my experience that very hard water, like I have here, can cause problems when washing paper. When I switched to softened water for washing paper, these problems went away. -Peter |
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