bringing color chemistry up to temp...is this safe?

cepwin · Nov 21, 2012

I was looking at color chemistry kits on b+h and someone in a review mentioned bringing the developer up to temp by microwaving it. While that would be very convenient I wonder if it is safe to do it that way? Can you destroy the developer by heating up too much? Boiling water baths work but take forever so if the microwave can do the trick that will make color development much easier.

Rudeofus · Nov 21, 2012

I have made it my personal rule that photochemistry does not mix with kitchenware. Some compounds in color developer are quite problematic and with heating you always create vapour. Unless you have a dedicated microwave for this I would strictly advise against heating your chems that way. Note, that the microwave will heat your chems unevenly, so you may end up with areas where your chems are much hotter than they should get while other areas are still cool. Remember, you can't stir in a microwave!

The way I have been heating my color chemistry without any of these problems can be described quickly:

Grab a bucket big enough to hold the bottles you store your color chemistry in
Fill it with hot water (50-60°C) from the tap
Put the bottles with your color chemistry into the bucket, make sure the water level stays a few cm below the liquid level inside your bottles, otherwise they might float and tip over.
Open the bottle with the first solution you are going to use and put the thermometer in
Wait until it shows the desired temperature and start processing
Leave the other bottles in the bucket for another 1-2 minutes, then take them out and dump the water from the bucket
During these 1-2 minutes they will gain some higher temperature, and by the time you need them they will have cooled back down a bit. Since the temperature of the second (and possibly third) bath is much less critical you should be fine without further adjustments.

tyqre · Nov 21, 2012

Instead of a bucket, you could also use hard shelled cooler, since they are insulated and may hold the heat a little better.

bvy · Nov 21, 2012

Rudeofus' method is precisely my own method. The hottest water from my tap is about 120F. It takes about ten minutes to bring 500ml of developer (and other chemicals) from room temperature (65F to 70F) to processing temperature (101F). During that time, I'm also conditioning my Paterson tank in a Playmate cooler filled with hot water, since I don't prewash.

newcan1 · Nov 21, 2012

I use a microwave all the time. But I don't use the same microwave for food -- not very often at least!

cepwin · Nov 21, 2012

Thank you for all the responses. It sounds like the hot tap water is the best. It seemed to take a lot longer than 10 min..perhaps I didn't have the water level high enough in my container. I like the cooler option as well..

bdial · Nov 21, 2012

If the time seems too long, walk away for a while and come back, you may well find you then have a cooling problem instead of a heating problem.

Or, set up the water bath at 1-2 degrees higher than your target then go do something else for 15 minutes or so, you'll likely need to fine-tune the method, but it may beat standing there watching things.

nickandre · Nov 21, 2012

I've used gas stoves and a double boiling arrangement when I was young and impatient. Heats up fast, and guarantees I won't scorch things that don't need to be scorched.

markbarendt · Nov 21, 2012

I will admit that I've used the microwave, and say that I did not cause a problem. I will also admit that it was likely not one of my smarter moments. Simply a convenience.

A much better solution was a $32 double hot plate from WalMart and two thrift store stock pots.

RedSun · Nov 21, 2012

I have a Jobo color processor and I'm very happy with it. If I want to heat faster, I can boil hot water and mix it with the cooler water and bring the water bath up very quickly.

If I want it to be really fast, I can heat hot water with my coffee maker, or heat the cold water in microwave.

But I never over-heat chemicals. The color chemicals are toxic... No microwave at all! The fume can kill you!

anikin · Nov 21, 2012

RedSun said:
The fume can kill you!

RedSun, aren't you exaggerating a bit?

RedSun · Nov 21, 2012

Well, it won't kill you right away, but it would certainly harm you.

Remember that, when microwave heats up things, the heat is not even. If you put a soup bowl or big cup of water in the microwave and heat it for 1-2 minutes, then you can tell that certain part of the content is hotter than the other. This is very bad for the chemicals. Imagine that the outer part of the chemicals are already 110F degree, but it is only 80F in the middle. I just do now know what is going to happen to the chemicals.

Sirius Glass · Nov 21, 2012

Use hot water and maybe a water heater, but skip the microwave for the reasons mentioned above and because a microwave will not give you the control over the temperature that you need.

cepwin · Nov 21, 2012

Thank you all for your input....yeah, a hot water bath seems the way to go..tnx again!

Mike Wilde · Nov 22, 2012

I have a darkroom microwave, vented as the sink is vented.

Very handy to heat previously boiled and stored R/O water when mixing a developer or fixer up up.

I have used this microwave to to heat up colur chems. I do it in 20 second bursts, and swirl the liquid in between.

You will find that blixes, with all the ferri in them, seem to heat very quickly; much faster than water it seems to me.

WayneStevenson · Nov 22, 2012

I use my microwave for my RA4 chemicals. Same one that I use for my food. The containers I use are only used for chemistry.

I don't worry about fumes / vapours. Microwaves aren't sealed units. Otherwise they would be a pressure cooker and you would probably have stream burns every time you opened it up.

They vent the air out the back. Or in my case, into the venting for my range fan.

Rudeofus · Nov 23, 2012

WayneStevenson said:
I don't worry about fumes / vapours. Microwaves aren't sealed units. Otherwise they would be a pressure cooker

Look at the area right above a used deep fryer: you will see a sticky goo that won't come off. Ever. And venting the area doesn't help in the least. When that goo was fresh, it was frying oil.

In other words: don't mess with the fumes.

cepwin · Nov 23, 2012

Thanks for the additional input...yeah even processing chemistry that isn't heated (ie. B/W) produces some fumes I would think heating only increases it. The vent fan in the small bathroom I use for a darkroom can only do so much. (And when I print I can't have it running or I won't hear the timer....usually run it after the session)

bringing color chemistry up to temp...is this safe?

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