Maintaining 100 degree Temperature

[whitecat]

I started doing my own C 41 and it calls for 100degrees. Any hints on how to keep the temp stable without spending a fortune?
Thanks

 

[Akki14]

I use a big storage tub in my bathtub and fill it with water to about 111F-107F and sit the glass bottles (heavier, don't float around annoyingly) of chemicals in there until a temperature probe (cookery type one) measures 100F. It should stay at 100F for your full 3min 15seconds needed for development, the rest of the chemicals aren't quite so important so they should still be within working leeway. I hold the paterson tank in the tub of warm water while I agitate with the little agitator (swizzle stick) at as constant of a speed as I can maintain. I take the tank out and the required bottle of chemicals and pour the chemicals in (or out) outside of the warm water tub. I just did 6 rolls of 120 film like this in the last 24hours (two rolls per reel, 500ml mixed up solution of the Tetenal ColorTec RapidBath kit). I keep the table with all the times next to me because it's easy to forget how long each step takes especially when you're starting out and panicing about filling and emptying and organising yourself.

 

[Michel Hardy-Vallée]

I'm doing RA-4 and I use a tub of water to stay in the ballpark. Before I process a sheet (I use a Unicolor drum), I turn on the hot water to bring the developer smack on the right temperature, I measure, and process. I more or less have to do it for every sheet. A minor annoyance, but my results have been good so far. Maybe I'll invest in an aquarium heater eventually.

 

[Mike Wilde]

Low budget C-41 temp control and other c-41 thoughts for you to get started on

Water bath, as others have suggested. Mine is a small (about 15L) picnic cooler (esky if you are Aussie/Kiwi).

I have fitted it with a 250W fish tank glass tube type heater. The heater's control dial on mine can be pulled up to allow it to ride over the stops that keep it within the healthy for fish randge, and let me tune it to give 100F. I alos have a fish tank water pump to alolow the chems to get warm water moving around them faster.

I get the chems coming up to temp when I get home from work; by the time that the dinner is eaten and dirty dishes done and put away all chens are ready to roll.

C-41 is likely best started from a fresh kit, but mixing your own is also feasible. I do, and am very happy with the results.

The developer is really only the finicky temperature part of the process; if the stop, and bleach, fixer or blix are a few degrees above or below, things won't go wrong.

I make the chemistry up in 1l quanities, and store it in brown glass bottles of a type called 'amber boston rounds'. This shape of bottle is good, becuase it minimises the amount of air in contact with the solution since it tapers at the top.

I color code the bottles with colored vlnyl electrical tape, and put a matching color tape dot on the lids so I don't mix them up. Regular masking tape floats off after sitting in a water bath for a while.

I also put a length of white tape on the bottle , and write on it with a 'sharpie' type indelible pen. I record on the white tape to indicate when I last mixed this chem, and put ticks on the bottle to indicate how many times I have re-used the solutions.

I do developer, stop, bleach and fix. By doing a separate bleach and fix, I find it is possible to replenish the bleach, so the process becomes very economical.

Developer is good for at least 8 roills of film until it becomes murky; I store up rolls until there are 8 rolls before I get a litre mixed. I have used murky/almost black developer, and it still seems to work fine, as long it is not too old ( Ie less than 1 month old); I suspect a lot of the murkyness is the anti-halation dye coming off the back of the film, rather than the developing agent oxidized and dead.

Stop is about 5% acetic and is used once, then poured down the drain.

Fixer is re-used until it fixer tests high in silver, or takes more than twice the time it takes to clear the film when it is fresh; I find this happens after about 15 rolls of film per litre. (35mm 36 or 120 roll).

Bleach is c-22 ferricyanide/bromide type, and I make up 2L at a time; one becomes the replenisher, and I feed in 45ml fresh replenisher per film bleached. When the bleach being used as replenisher is all used up, then the overflow and working solution go out as hazardous waste to the local depot, along with exhausterd fixers, etc.

There are plenty of water wash steps to keep the differnet chems from being cross contaminated.

 

[DBP]

In some parts of the south, July and August suffice.