Properly "cooking" D-76 - can you use a large pot?

moodlover · Jul 28, 2015

I'm new to film chemistry and about to start developing b&w at home and was wondering what an easy way to mix D-76 properly is and how to maintain 120F temperature. I was wondering if I could put 3/4qt tap water into a large pot (purchased solely for mixing chemicals, not cooking), measure the water's temp until it reads 120F and then dump the D-76 into and stir.

Would this work?

Photo Engineer · Jul 28, 2015

As long as the pot and the mixing instruments are not made of aluminum or copper (brass, bronze etc...).

PE

Gerald C Koch · Jul 28, 2015

You don't need to maintain the recommended temperature, only start with it. Heat the water and then put it in a suitable container (Pyrex glass or stainless steel) and add the contests of the D-76 bag. Then stir until all is dissolved. The actual temperature is not that critical. It only speeds up solution. Water from the hot water tap may be hot enough.

moodlover · Jul 28, 2015

What does the pot have to be made of? Would stainless steel be okay?

moodlover · Jul 28, 2015

Gerald C Koch said:
You don't need to maintain the recommended temperature, only start with it Heat the water and put it in a suitable container and add the contests of the D-76 bag. Then stir until all is dissolved.

This is how I've seen it done but my reasoning was that I wanted to stir everything in the pot to ensure it dissolves fully before pouring it into a filtered funnel to remove any excess lumps. If I pour the water directly into the plastic chemical container I have, then dump the powder into this bottle, how would I get rid of the lumps waiting inside?

MattKing · Jul 28, 2015

Use hot water from the tap (tempered to 120F), and a plastic or ceramic mixing container.

An ice cream pail works great.

removed account4 · Jul 28, 2015

MattKing said:
Use hot water from the tap (tempered to 120F), and a plastic or ceramic mixing container.

An ice cream pail works great.

i use a large dollar store tupper ware tub or a 5 gallon bucket.

DWThomas · Jul 28, 2015

I heat distilled water in a large Pyrex measuring cup, then mix stuff in one of those large polyethylene drink pitcher/storage containers so I can stir with a plastic paddle until everything is dissolved. In general I use plastic or glass and keep metals away from photo chemistry (except for developing tanks and reels).

moodlover · Jul 28, 2015

Okay so I'll get a large plastic pitcher to mix everything in, but how do we heat our water? I really don't want to use my tap water directly because sometimes it looks funny.

DWThomas · Jul 28, 2015

moodlover said:
Okay so I'll get a large plastic pitcher to mix everything in, but how do we heat our water? I really don't want to use my tap water directly because sometimes it looks funny.

Hmmm, I meant to say I heat the water in a microwave. The 1 gallon mixing container is too tall to fit, so I zap a couple of shots in a smaller container, such as a 1 quart "measuring cup."

MattKing · Jul 28, 2015

moodlover said:
Okay so I'll get a large plastic pitcher to mix everything in, but how do we heat our water? I really don't want to use my tap water directly because sometimes it looks funny.

Where are you located, and are you on a well or a municipal water supply?

The packaged developers include chelating and other agents to help deal with variations in water quality.

moodlover · Jul 28, 2015

Im in NYC so its probably on a municipal water supply. The water here's supposed to be clean but my pipes are weird sometimes unfortunately.

Rick A · Jul 28, 2015

I heat distilled water in the microwave in glass 4 cup measure to 120f-130f then dump into my 5 qt. mixing tub, stir until dissolved. I then decant into 3 one quart bottles filled to the top and tightly capped. The remaining quart gets decanted into 225 ml bottles.

Xmas · Jul 28, 2015

I use an electrical kettle plastic boil the faucet cold water to remove some of the hardness let it cool in polythene container and add the powders, stir a bit, screw on top and decant to a concertina storage the next day I'd not filter any solid residue, - there should not be any.

There could be copper and other metal residues in the hot water system.

As I use it stock I filter the used developer when I pour it back into to stock bottle as I sometimes get emulsion chips cause I use a lot of cine film.

It is simpler to mix in your stock bottle and leave overnight, but I'm more cautious cause I weigh out raw chemicals... Using Kodaks chemicals I'd not bother.

Relax D76 is easy. Pour powder in slowly but please try not to breath the dust.

Gerald C Koch · Jul 28, 2015

moodlover said:
This is how I've seen it done but my reasoning was that I wanted to stir everything in the pot to ensure it dissolves fully before pouring it into a filtered funnel to remove any excess lumps. If I pour the water directly into the plastic chemical container I have, then dump the powder into this bottle, how would I get rid of the lumps waiting inside?

The lumps will dissolve with the hot water. I think you're worrying too much. Use a plastic bucket and a plastic or stainless steel spoon to stir.

cliveh · Jul 28, 2015

All you need is a kettle of boiling water, a plastic bucket, stirring rod and a cold tap.

GRHazelton · Jul 28, 2015

I wouldn't worry about using a stainless steel cooking saucepan to heat distilled water for mixing a developer. Just wash thoroughly before food use. Polyethylene pitcher? Either mixing developer or mixing lemonade, not both! Glass pitcher, just wash thoroughly. Glazed ceramic should be fine, although surface crazing would be a concern. Other materials, aluminum, etc, no. Might well react with the chemicals in the developer.

I use distilled water for mixing my D 76, dilute with distilled for 1 to 1 use, wash with tap water - ours is quite good, and use distilled for a photoflo rinse. In these quantities distilled is "cheap."

Years ago I began a darkroom printing session, mixed my Dektol with tap water, as usual and......NO ACTIVITY. I couldn't find any evidence of contamination at my end, so...I called the water department. Seems they'd put a "harmless" slug of acid, probably HCl, down the pipes to "clear things out." A potent stop bath, and a good argument for mixing ALL chemicals with distilled water.

moodlover · Jul 28, 2015

What about the developer being exposed to oxygen? There seems to be two trains of thought on this:

1. Pour the hot water into gallon, pour powder into gallon, cap it and mix for a few minutes by shaking or "wine stirring" - this method prevents oxidation
2. Pour the hot water into a bucket/pitcher/tub/etc, pour powder in, mix and stir with paddle in the open air, pour into bottle - this method doesnt

Thoughts?

cliveh · Jul 28, 2015

moodlover said:
What about the developer being exposed to oxygen? There seems to be two trains of thought on this:

1. Pour the hot water into gallon, pour powder into gallon, cap it and mix for a few minutes by shaking or "wine stirring" - this method prevents oxidation
2. Pour the hot water into a bucket/pitcher/tub/etc, pour powder in, mix and stir with paddle in the open air, pour into bottle - this method doesnt

Thoughts?

Exposing the developer to oxidation during mixing is not a problem, but after mixing it is.

DREW WILEY · Jul 28, 2015

My hot water tap is warm enough by itself. But if I need to used distilled water, I have a little single-coil portable stove and heat the water
in a pot, then pour it into the mixing vessel. Easy enough. But 76 is odd. You either want to standardize on it fresh, the same day, or let it
reach equilibrium about a week later, in which case it stays stable six weeks or so, if kept in airtight bottles. In the latter case, I divide the
mixed developer into little one-use brown bottle quantities. If using the developer 1:1, just add the extra water at the actual time of use.

randyB · Jul 28, 2015

Don't just "dump" the D76 in to the water. You add it slowly while stirring the hot water in a circular motion. By adding the chemicals at a slow rate you give it time to start to dissolve without clumping. Continue to stir for several minutes after the last of the chemicals have gone into the solution. Let it rest for a little while, you may see some undissolved chems on the bottom of your bucket at which time you stir some more. Back when I used powder chemical developers I always waited several hours after mixing before I used them.

pbromaghin · Jul 28, 2015

I just heat some water in the microwave, mix up the amount of 1:1 I need for the session, and keep the rest of the powder in a plastic container in the fridge.

cliveh · Jul 28, 2015

pbromaghin said:
I just heat some water in the microwave, mix up the amount of 1:1 I need for the session, and keep the rest of the powder in a plastic container in the fridge.

No, no, no. You must mix it all to make the stock solution.

DWThomas · Jul 28, 2015

I "stir" the powder in, pouring slowly, but by stirring I mean keeping the liquid moving to maintain any undissolved powder in suspension, not whipping the mix to a froth.

GRHazelton · Jul 28, 2015

A kitchen "mixer" for dissolving photo chemicals??

Hmmm.....Looking in the kitchen cabinets I noticed a hand-held mixer, the sort with interchangeable heads - a whisk, and a little guarded chopper blade on an extension, good for eliminating gravy lumps, etc. Its stainless steel, washable, and about 9 inches long to where it connects to the A/C power head. Used in its intended manner it really stirs things around, but doesn't introduce air, if kept well immersed. I wonder if this would be a good way to mix chemicals, lacking a heated magnetic stirrer??

Properly "cooking" D-76 - can you use a large pot?

moodlover

Photo Engineer

Gerald C Koch

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MattKing

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DWThomas

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Rick A

Xmas

Gerald C Koch

cliveh

GRHazelton

moodlover

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DREW WILEY

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Properly "cooking" D-76 - can you use a large pot?

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