Dividing and store chemicals

[will_weinzettl1]

I have a few questions on photo chemical powders.

 

Recently I bought the larger sized bags of Developer, Fixer and HCA

(they mix to 3.8 litres rather than 1 litre) and I'm planning on

dividing each of them into 4 portions so I can mix 4 x 1 litre

rather than 1 x 4 litres.

 

How airtight & light-tight do unmixed powders have to be?

Is it enough to store them in ziploc bags and store them in the dark

somewhere? If Ziploc bags are enough, should they be the thicker

variety?

 

Thanks

[al_kaplan1]

Unfortunately there's no way to guarantee that the powder in the pouch is evenly mixed. It's best to make up the full amount at once. This is especialy true of developers. When you divide it into 4 one litre bottles fill three of them all the way to the top of the bottle so no air is inside. The fourth bottle will will only be about 3/4 full. Use this one first. Store the rest in a cool dark place, which is a pretty good description of most darkrooms anyway. They should keep for 3 or 4 months, much longer for fixer and HCA.

[will_weinzettl1]

That's a bummer.

 

I've done fixer split in 2 before (made 2 x 2 litres) and I didn't see any problem. I guess it's probably a little more crucial for something like developer.

 

It bites that there is no interim size of powder.

[david_cuttler]

I have divided the chemicals, both developer (D-76) & fixer. I really stir the whole package of powder in a stainless kitchen bowl, then use a small measuing cup to go from bag to bag one cup full at a time untill all the stuff is divided. I use Zip lock bags, making 1 qt. of d-76 at a time. I have never had a problem. The measuring cup is a 1/4 cup in quantity this means it will take a number of rotations to finish the job.

[stuart_todd]

Another quick tip. I buy the big five litre Ilford ID-11 developer pack and mix it all up in one go in a bucket, I bought just for mixing up film developer. Once all mixed up I then split it into five one litre bottles, but as you will discover there is always still some air between the cap and the top of the liquid. So on the four I plan to store away, I take a bag of washed marbles (yes, those round glass things that kids use to play with before playstation) and drop them in bringing the liquid level upto the brim. Once you put the cap on, if the bottle is clearish, invert it and in theory you shouldn't see any air bubbles rise in the bottle. Or use wine bladders... but there is still a major problem with using wine bladders.

 

Stu :)

[m0002a]

You can divide powder chemicals, but it can be a little risky if the grains that make up the various chemicals used in the formula are different sizes. Smaller grains tend to settle near the bottom of a package. For that reason, it is not recommended to divide powder chemicals.

[will_weinzettl1]

I think I'm going to go with David's idea of mixing them in the bowl.<br><br>

 

I just hope that the laws of averages are on my side and I get roughly equal mixes of particles. I think if I do it the way that David explained, the smaller/larger particles will go into each bag in more or less the same amount.<br><br>

 

It's scary when you look at the costs on non-bulk chems.<br><br>

<ul>

<li>4 x 1 Litre packets of D76 (@$4.99 each) = <b>$19.96 CDN</b><br>

<li>4 x 1 Litre packets of Fixer (@$3.99 each) = <b>$15.96 CDN</b>

</ul>

  <b>OR</b>

<br><br>

<ul>

<li>1 x 4 Litre packet of D76 (@$6.99 each) = <b>$6.99 CDN</b><br>

<li>1 x 4 Litre packet of Fixer (@$6.99 each) = <b>$6.99 CDN</b>

</ul>

Oh, and don't forget to add ~15% tax on top of that.

<br><br>

Thanks to all, I'll let you know how it goes once I mix them up.

[graphicjoe]

Will,

I don�t know just how much bother you are willing to take, but you might consider mixing your own chemistry from the individual chemicals. I�ve never done, but have read that it�s the least expensive way get the products you desire. And you would be able to mix any amount desired.

 

Take care not to breath any powered chemistry, especially developers.

 

Cheers,

 

Joe Stephenson

[al_kaplan1]

Back in my student days we discovered another way to hold down chemical costs. Several of us would get together to buy the bigger packages, mix it all up, pour it into bottles and divide up the bottles. All you need is a few other friends to get in on this with you.