Residue on film.

After developing for a good year now, I'm still finding that my negatives have some specs and residue on them. I think it's mostly dry marks. I use 3 drops of photoflo per 250ml dev tank, and then rinse with distilled water, and then hang dry in my bathroom. I'm wondering if it has something to do with using tap water? Would it be beneficial to develop with distilled water? Regardless, I'm stuck rinsing with tap water. I'm not sure how much little marks here and there matter during printing, but they sure show up when scanned. I print some in the darkroom now, but hopefully more in the future, so I'd like to get this right.

Thanks,

Mark

That seems like a lot of photoflo. 3 drops at the recommended dilution would result in 600 drops of working solution, which is probably more thn 250 ml.

You should make up your photoflo solution with distilled water, and then refrain from rinsing afterwards.

I make up a stock solution of 25 ml of photoflo and 175 ml of 70% isopropyl alcohol. That stock stores well. I then dilute that stock 1+24 with water just before use. The alcohol aids in drying, and the small quantities of stock are much easier to measure repeatably than drops.

APUGuser19 said:

Why are you rinsing after the photo-flo bath? "Tap water" could mean anything. Water from my tap comes from a well and is hardly good enough to water the hogs. Or tap water could mean in the city, or at the beach. "Tap water" is a nearly useless descriptive.

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,

I don't know why I'm rinsing after the bath… I guess that doesn't make sense!

I live in Chicago, so I'm using the city water, that comes from the tap.

MattKing said:

That seems like a lot of photoflo. 3 drops at the recommended dilution would result in 600 drops of working solution, which is probably more thn 250 ml.

You should make up your photoflo solution with distilled water, and then refrain from rinsing afterwards.

I make up a stock solution of 25 ml of photoflo and 175 ml of 70% isopropyl alcohol. That stock stores well. I then dilute that stock 1+24 with water just before use. The alcohol aids in drying, and the small quantities of stock are much easier to measure repeatably than drops.

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Thanks for the advice. I've never heard of using alcohol before. So 1+24 would add up to roughly 10ml/20ml stock solution of photoflo/alcohol for 250/500ml developing tanks?

mporter012 said:

Thanks for the advice. I've never heard of using alcohol before. So 1+24 would add up to roughly 10ml/20ml stock solution of photoflo/alcohol for 250/500ml developing tanks?

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Correct.

I have really hard tap water, and was having an insane amount of dust and water residue on my negatives. I use a Paterson tank (FWIW).

From reading here on APUG, here's what I've learned, and how I do my final steps;

final bath under running tap for about 7-10 minutes
empty the last of the water, and shake the tank to get as much out as possible
fill with distilled water
add 1 drop of Dawn dishsoap (Fairy in the UK)
gently agitate with the spinner - no inversions! Try not to create suds
pour it out and hang - no squeegeeing with anything

I do these steps in a small bathroom (the main portion of developing is done in the kitchen). While doing the running tap water bath, I turn on the shower to hot, and let it run for the 7-10 minutes to really steam up the bathroom. This gets the air-borne dust to settle. Ever since I started doing it this way, I have no streaks, water residue, or dust on my negatives.

APUGuser19 said:

There are 591.47 drops of water in an ounce. So your photo flow is a bit too week AND you're rinsing it away, to boot.

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But how many drops of photoflo are in an ounce ?

That is actually a serious question, because the size of each drop is affected by surface tension, and photoflo will have different surface tension than water.

And of course, one needs to ask "which ounce?" as well.

I followed all sorts of "advice" from internetters about how much wetting agent to use in final rinse ... and I still had all sorts of problems with marks and streaks and whatnot even when using DI water.

Then I (gasp) tried the manufacturer's recommendation just like it says on the bottle (Ilfotol 1+200), and guess what? All my negatives are perfectly clean, every time.

I have a gallon jug that contains 1 gallon of distilled water and a 1/2 ounce of Photoflo that i use at the end. For developing, stop, fix and rinse i use tap water and at the end i give it a 30 bath in the distilled/photoflo. I have never had a drying mark on my negatives.

1. Get an in-line water filter. Finding ones that filter down to five microns is no problem. I have one that just slips over the faucet... easy and will eliminate your particulate problem (if you have one).

2. Use distilled water and PhotoFlo for the final rinse. Soak the negatives longer than the recommended time if you have hard water so the ion exchange can stabilize. More time won't hurt. Don't save and re-use PhotoFlo. If you do, two things can/will happen: organic slime can develop (bacterial sludge) and the levels of hard-water minerals will increase, effectively neutralizing the reason you use distilled water for the final rinse in the first place. Mix what you need for a session and discard it afterwards. Oh yes, mix according to the directions on the bottle.

Best,

Doremus

In case it isn't clear, the procedure I use does result in a 1:200 dilution, as per Kodak's specs.

And the alcohol stops slime.