Question about developer mixing

manfromh · Aug 22, 2006

Is it smart to mix (i dont know if thats the right word) all the developer at once? Or should i mix only as much as i need at the time? And whats the best way to store it? I got some d76 powder developer. I havent developed any films yet, but i want to do it in few days. Got 5 rolls waiting.

Torus34 · Aug 22, 2006

You should mix all of the developer at once. A developer is a mixture of several chemicals, not just one. There are four in D-76. You have no assurance that the various components are thoroughly mixed in the dry powder form.

Developers slowly react with the oxygen in the air. If you can keep the developer in a 'squeeze-able' bottle which allows you to remove most of the air, great.

You might want to consider this:

Determine how much developer is required by your tank. Find a bottle which holds that amount. Collect enough clean, empty bottles with good caps to hold the quantity of developer you will mix up. Mix the developer and portion it out in the bottles, filling them almost to the top. Then just use the developer a bottle at a time.

My basic tank holds about 16 ounces and two 35mm reels. 'Snapple[tm]' bottles are just the right size. I've cut cap liners from rubber sheet to keep the caps from rusting out. I need 7 bottles/gallon of developer. That's 14 rolls/gallon. I mix, store and use fixer the same way. If you are not concerned about squeezing the most rolls out of the developer, it's a good way to go. The developer in the bottles will keep for the full time stated by the manufacturer.

JamesD · Aug 22, 2006

Por powdered chemicals, always mix the full amount. For liquid concentrates (like TMax) mix only what you need. The liquid concentrates tend to last pretty well.

I prefer to use the smaller-size Gatorade bottles after making sure they're very clean. There's air left in the bottles after filling it with a single-use amount of developer, but I force the air out by dropping in clean glass marbles. A small screen strainer (thoroughly rinsed and dried after every use) keeps the marbles out of the tank lid.

And yes, "mix" is the right word

ksmattfish · Aug 22, 2006

If you want to mix up smaller amounts, consider using a liquid developer. There are many that are very similar to D-76.

mysteryscribe · Aug 22, 2006

You can mix your d76 powder in about half the suggested water. Then dilute as needed but again keep it in full bottles not partially full. I have bottles that are 32 16 12 8 and 4 oz. Its easy to collect them. Lots of fruit drinks come in 8 & 12 oz sizes. lots of medicine bottle ect come in four oz even less sometimes.

Im pretty sure the half the water mix is all that liquid d76 and dektol is. Im most likely paying for the bottle but I dont like mixing dry chemicals. I'm not that much of a purist.

Thought when I had a full dark room, I actually did break the dry chemicals down to smaller pickets and seal them in plastic. At the time I had a very nice vibrating table to keep the dry chems pretty well mixed. I never noticed any problem with them. The biggest problem I had doing that was the chemical getting moisture while in storage. We are talking a bar of soap when I got to the end.