Major riders: Temperature. Very cold water is never gonna shift anything anyway.
SNIP
regular old cold tap water will work fine.
the way the "stuff" leaves the film and paper is
through osmosis --- water exchanges + soaks work.
it really doesn't need to be more technical than that ...
John;
Osmosis requires a membrane such as a cell in a human body.
Film contains no membranes, per se, and therefore only diffusion applies, not osmosis.
PE
Where does something like Ilford "Washaid" fit in all this. Or is it more of a paper wash aid.
Your conclusions about when to use wash aids are right on, but I have a problem with the term "wash aid" being characterized as synonymous with "hypo eliminator". They are not at all the same.Washaid is a hypo eliminator ...
"Hypo eliminator usually refers to a solution containing hydrogen peroxide or peroxide-releasing compound such as percarbonate, perborate or persulfate. These solutions may also contain ammonia, other alkaline agents, bromide, iodide, and other additives.
The idea behind hypo eliminator is to oxidize thiosulfate to harmless compounds that are not adsorbed by silver surface. However, it was later found that peroxide solutions damage and undermine image-forming metallic silver. Today, the use of hypo eliminators are discouraged."
In either case, you are adding a burden to the environment. The sodium sulfite in a wash aid has to go somewhere, and peroxide in your effluent is not nice either.
PE
Your conclusions about when to use wash aids are right on, but I have a problem with the term "wash aid" being characterized as synonymous with "hypo eliminator". They are not at all the same.
I know it sounds rather nitpicky, but I hope the terminology of wash aids and hypo eliminators becomes better understood and used since all these terms can be so confusing to beginners under even the best circumstances.
I also don't know if hypo eliminators really make a huge difference with rapid fixers that do not contain any hypo, when using the short fixing times with modern films and RC papers.
Hypo eliminators are completely different; they
destroy hypo within the paper rather than
helping it be removed from the paper.
Wash aids are rather gentle in effect, merely allowing better
diffusion of water and chemicals in and out of the paper base.
I know of no fixer today that has another fixing agent in it that exclusively replaces Hypo. Can you explain a bit? Thanks.
PE
Maybe this is a sophomoric assumption, but I figured that
as long as there are 15-20 total changes of water, I'd be
good. What I currently do, then, when using a inversion
tank to develop film is:
I empty the tank of fixer - I fill the tank up completely
with water once and dump it - I fill the tank up with
water to just barely cover the developing reels and
dump it - I repeat the "fill to the reels" step 15
times - I repeat the "fill to the reels" step -
twice more with distilled water
Wirelessly posted (BlackBerry 8300: BlackBerry8300/4.5.0.55 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)
Just use the Ilford wash method for film. It's archival and uses a minimal amount of water.
Nick
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?