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View Full Version : scum or deposits on negatives driving me cuckoo



Jordan
16-Nov-2007, 19:07
I am always getting some sort of scum or deposits on my negatives after they dry. I use photo flo and dilute it out as I know this helps, but still always some crap on my negs. I read that rewashing in stop bath helps to get rid of this on already washed and dried negatives. After I use the stop bath should I refix or could I give the negs a little rinse then put them into some PermaWash and then back into the wash?????? Please let me know this is driving me nutso!!!!!!!!!!!!!!!!!!!!!!! Would the second stop bath have an effect on the archival qualities of the neg? Is using the stop bath a bad idea to clear the crap off my negatives? I appreciate your time.

Jordan

Ed Richards
16-Nov-2007, 19:19
What kind of negatives? What kind of crud? Are you washing them in distilled water for the last couple of rinses? How are you drying them?

Oren Grad
16-Nov-2007, 19:21
I'm not sure about washing off the residue once it's there, but a couple of things to try for future processing runs:

* Mix your PhotoFlo with distilled water.

* Dilute the PhotoFlo a bit more than the instructions say - I used to get a bit of residue at 1+200, but it works fine for me at 1+300.

Jordan
16-Nov-2007, 19:27
Film is 8x10 Tri-X. Crud is white crust like deposit stuff that doesn't usually affect printing, BUT can. Haven't used distilled water, but will. Still though would you guys think that running a negative back through the stop after it's been already dry would some adverse affect on the film? You guys are awesome for your quick responses as I still washing my negs.

Jan Pedersen
16-Nov-2007, 19:36
Jordan, i have rewashed negatives without negative effect, as long as you handle your negs carefully there should not be any reason why you can't rewash.
Depending on your location which i forgot you could have a lot of minerals in your water and in case you have, distilled water really is needed for the last couple of rinse. I am real lucky here in the NW where water is soft, one drop of photoflo per 1/2L of distilled water is enough to make the negatives look spotless.
Keep trying and you will succeed

Jordan
16-Nov-2007, 20:00
How about something to remove the scum from old negatives?

Jan Pedersen
16-Nov-2007, 20:13
Try do a 10 - 15 minute rewash with a couple of distiled water rinse with photoflo in the end. No guarantie but i am pretty sure it wont get any worse than what you got.

Jordan
16-Nov-2007, 20:17
Thanks Jan, I'll give a try tomorrow.

Jan Pedersen
16-Nov-2007, 20:24
Jordan, Leave the negatives in the disitlled water for at least 2 minutes in the end with plenty of agitation.
Minerals are good for many things but very bad for negatives. Good luck.

davidb
16-Nov-2007, 20:31
Sounds like hard water.

Jordan
16-Nov-2007, 21:05
Could this residue eat away at the negative over time? Damn minerals and hard water.

davidb
16-Nov-2007, 21:08
I have this same problem and until I spend a few thousand on a water softener, I am using bottled water for my negative processing.

It's a pain in the ass but it works.

Colin Robertson
17-Nov-2007, 02:33
I have lovely soft water, but it still contains some kind of suspended organic material. I process and wash in tap water but now use filtered water for final rinse. Smooth, clean negs. It's one of those cartridge systems that filters into a jug. Meant to give cleaner drinking water. Works great for me, cheap staring point to experiment solving your problem?

Brian Ellis
17-Nov-2007, 20:22
"Still though would you guys think that running a negative back through the stop after it's been already dry would some adverse affect on the film?"

I don't think it would hurt the film but I also don't see that it does any particular good either. What's supposed to be the purpose of using stop? Stop bath just stops development and readies the film for the fix. Obviously you don't need to worry about stopping development and since the film has already been fixed once there's no need to fix it again. So I'm not sure what purpose the stop serves that water wouldn't.

As others have said, the standard remedy for the kind of thing you're talking about is a rinse in distilled water. I quit using Photo Flo a long time ago, partly because it's kind of soapy and if too much is used it can actually leave its own residue. When I did use it I only used about half the amount Kodak recommends. I preferred Edwal LFN to Photo Flo, it seemed to do just as good a job but wasn't soapy. I don't know if it's still made or not.

Jordan
17-Nov-2007, 20:24
So I tried rewashing the negatives today using the regular film washer for 20min. and then into some distilled water with photoflo and alcohol..... no change. The negs that had the mineral deposits still have the mineral deposits. Will these mineral deposits eat away at the emulsion over time????? This is driving me nuts.

Brian Ellis
18-Nov-2007, 10:53
So I tried rewashing the negatives today using the regular film washer for 20min. and then into some distilled water with photoflo and alcohol..... no change. The negs that had the mineral deposits still have the mineral deposits. Will these mineral deposits eat away at the emulsion over time????? This is driving me nuts.

Since I don't know what the minerals are it's hard to say if they will eat away at the emulsion over time. But it sounds like you need to do more than just rinse the film in a film washer. Take a sheet you don't care too much about. Warm up some distilled water, not hot just warm (don't worry about Photo Flo for now). Put the water and film in a tray and lightly scrub the deposits with your wet fingers. If the deposits are on the base side you can rub pretty hard, if they're on the emulsion side you'll need to be a little more careful but you should be o.k as long as you don't scratch the film. Maybe others have better suggestions but I've rubbed water spots and stuff off of film this way without damaging the film. I have no idea if it will work with your deposits but it seems like a logical next step.

Brian Ellis
18-Nov-2007, 11:07
So I tried rewashing the negatives today using the regular film washer for 20min. and then into some distilled water with photoflo and alcohol..... no change. The negs that had the mineral deposits still have the mineral deposits. Will these mineral deposits eat away at the emulsion over time????? This is driving me nuts.

Since I don't know what the minerals are it's hard to say if they will eat away at the emulsion over time. But it sounds like you need to do more than just rinse the film in a film washer. Take a sheet you don't care too much about. Warm up some distilled water, not hot just warm (don't worry about Photo Flo for now). Put the water and film in a tray and lightly scrub the deposits with your wet fingers. If the deposits are on the base side you can rub pretty hard, if they're on the emulsion side you'll need to be a little more careful but you should be o.k as long as you don't scratch the film. Maybe others have better suggestions but I've rubbed water spots and stuff off of film this way without damaging the film. I have no idea if it will work with your deposits but it seems like a logical next step.

Gary Beasley
18-Nov-2007, 11:19
Use this advice with caution- The minerals here are the same as the scum and scale that accumilate on fixtures in hard water areas. The most effective way to remove these deposits is with a weak solution of hydrochloric acid, which is what most commercial heavy duty scale removers have. The chloride compound of most metals are very water soluble (silver is a notable exception) so if a metal carbonate or sulfate has deposited on something an ion exchange with chlorides will dissolve most of them. Film should tolerate a weak acid fairly well as this is what is used in stop bath and as hardeners in fixer. The notion that stop bath will remove scum only gets you partially there, many acetate compounds are not very soluble. The correct way to use it is to add a small amount of sodium chloride- common table salt- to the stop bath to provide chloride ions to exchange for whatever is in the scum and allow it to dissolve. This is the easiest way to create hydrochloric acid from easily available compounds, I use vinegar and salt quite often to remove rust stains from my countertop in my kitchen.
Try this on a sacrificial negative first to see how well your film will tolerate it.

Ed Richards
18-Nov-2007, 11:23
You might also try soaking a negative in a baking soda solution.

walter23
18-Nov-2007, 11:25
We have really hard water here and I get a couple of spots unless I use LFN wetting agent. I don't use photo flo or hypo clear. Just a generous amount of rinsing in tap water followed by the addition of a drop of the wetting agent, then hang dry.

Toyon
19-Nov-2007, 07:10
For removing the stains use distilled water with the addition of a small amount of sodium sulfite. Rinse in distilled water afterwards.

gbogatko
19-Nov-2007, 10:57
I don't get spots, I get an even coating of something else on the neg. Ekfe 25 dev. with Pyrocat HD in glycol. I believe I read that agitating too quickly with Pyrocat will do this. Sometimes I think it's the photoflo even if it's a fresh batch and soft water. I have a few choices, leave the coating on and just let it dry, wipe it off under running water with my latex-gloved fingers, don't use photoflo.

God forbid I touch the neg while hanging it or else the stuff comes off just where I touched it and drys that way -- very exasperiting.

any suggestions?

George

Gary Beasley
19-Nov-2007, 11:09
Use distilled water as a final rinse and no photoflo, see what that does.

Jordan
20-Nov-2007, 20:09
Could it be the gloves I use sometimes leave this residue????? They are white non-latex gloves........ The stuff that is on the negs already simply won't come off. It is a white practically transparent residue. Sometimes it happens other times it doesn't. I can't think of any variables between the times it does and the times it doesn't. Still perplexed and annoyed.

dkmacc
21-Nov-2007, 04:06
Jordan,

First try removing your gloves and rinsing your hands while your negatives are washing. The gloves may have a powder coating and that could be the source of the crud you are fighting. Gentle handling of negatives with clean bare hands should not cause any problems.

When I first started processing 4x5 sheet film, I had all kinds of problems producing clean negatives. After much trial and error, I starting using the procedure described below. I am fully aware that what works for me flies in the face of conventional wisdom and I don't need to be reminded of that by other forum members. All this is offered to help you and should not be considered EXPERT advice. I am not an expert in anything.

First thing I did was give up on using a wetting agent of any kind especially PhotoFlo. Now I just wash negatives in our moderately hard water, the same public water supply I have used for many years for washing hundreds of rolls film. I use the Ilford abbreviated wash procedure to save time, water and effort. Next I rinse the negatives in plain distilled water for a minute or two with plenty of agitation. Then I gently wipe the negative surfaces with a clean windshield wiper blade. Clip and hang to dry and the negatives are ready to proof by the time I clean up from processing and fill trays to print. The key to drying quickly here at home is an indoor relative humidity that averages 50% all year and hanging the negatives in the open air but away from direct air currents.

I sincerely hope you solve the problem you are facing and that my simple description of what works for me is helpful to you.

Don