Mixing up old (20 y/o+) D-76 from powder.

Nicholas Lindan said:

Despite the hysteria, the folks who have worked in industrial compounding can attest that uniform powder mixtures are not a problem.

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But a warning not to part powder packages was approved by a manufacturer nonetheless.

AgX said:

But a warning not to part powder packages was approved by a manufacturer nonetheless.

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Sure, doesn't cost a damn thing and covers one's arse. And keeps people from dividing out powders - which is a bad idea not because of stratification but because of oxidation.

MattKing said:

And the OP's container has ~4,150 gm in it, so proceeding this way will mean you will be doing this 176 times.
The likelihood of the mixture being effectively the same (first to last) after that many iterations is not great.

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I answered his question. He asked how much to mix a small amount. That is to test it. He can then mix the entire 5 gallons-500ml, if he wants.

Whether or not it works is actually really obvious once you've done it.

And it's not about penny-pinching. It's normally about not having a 5 gallon jug to keep it in - or a 1 gallon jug, for that matter.

We should go back to talking about whether or not paper should be under the grain focuser.

michael_r said:

I just don't get why people try to save a few pennies on things like this. Next thing you know, a new Photrio thread: "Help - thin negatives from D-76 - what happened?"

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Micheal, it may not be wise to deliberately buy 5 gal of powder with the aim of subdividing it into small amounts just to save a few pennies but the thread simply asked if there was any way to do this as a result of having 5 gallon's worth of powder that appears to have been "rediscovered". Thus it seems to me to be a perfectly sensible question to ask as the alternative is to dump it and thus lose it.

Opinion is divided but it appears to be divided on a close to 50/50 basis. So not a crazy idea in the way that asking if a water wash can be eliminated in the development process would be.

So it might be possible. In fact in theory it is definitely possible if you can be sure of getting close to the right proportions of each ingredient. However what is more of a concern is the fact that the bag was opened 2 summers ago so air is now present. However the OP says that the powder has not clumped nor does it appear to have any moisture at all so presumably is free running and, assumption on my part now, is still the same colour as it originally was

So this begs another important question: Namely, if the powder retains the same colour and is totally free running i.e. is moisture-free, can we assume that it is still OK and if not what can air do that does not affect its free running qualities or colour but still creates problems that cannot be seen?

If the answer is that the air can do nothing that does not affect its free running or colour such that if you can see no visible signs then there is no adverse affect then this removes the problem of the air and gets us back to the question of whether a user can retain the correct portions of the ingredients by simply thoroughly shaking the packet and pouring the right weight, doesn't it?

Anyone know? Thanks

pentaxuser

Don Heisz said:

We should go back to talking about whether or not paper should be under the grain focuser.

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And we haven't yet properly resolved the issue of stop-bath usage.

Yes, we speak of things that matter
With words that must be said
"Can analysis be worthwhile?"
"Is the theater really dead?"

Nicholas Lindan said:

And we haven't yet properly resolved the issue of stop-bath usage.

Yes, we speak of things that matter
With words that must be said
"Can analysis be worthwhile?"
"Is the theater really dead?"

Simon & Garfunkle​

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