Protection Spray & C41 Dev

A couple questions!

If I mix up some C41 developer in a 5gal jug and use protection spray, how long can I expect it to stay fresh? I'd like to mix some up tomorrow, then do a few runs with my Phototherm, but after that I won't have more rolls until early next week, to mid next week. When using protection spray, how long can I expect a working 5gal jug to last?

Also the instructions on protection spray are a little vague. How long do I spray it in to fill the jug, and do I have to re-fill it on a regular basis? The jug will be sealed by cap, with only a tube from the Phototherm coming in a small drilled hole. I can seal this too if you recommend I do so.

Thanks!

Protection spray meanwhile is nothing else than Propane/Butane.
Measuring the flow from such can is difficult. Also it is not clear whether there is a true substitution of air by that spray, as that depends on flow dynamics.
By using cheaper camping/heating gas instead you can be more generous in application. The same time the hazard grows.

A lot will depend on the level of liquid after you have used what you need. I used to use stuff called Protectan in the U.K. which may have been Propane/Butane. I cannot recall. What I d recall is that a quick squirt goes a long way as all you are doing is spreading a layer of gas over the liquid surface which is heavier than air. The air is displaced and remains above and cannot penetrate the heavier gas layer.

Every time you pour out the liquid you disturb the gas and need to respray. I haven't used |gas for some time. With 5 gal and using it a little at a times I am now going to go into my stuck record groove which keeps repeating: Use empty winebags or get custom-made bags and boxes from a homebrew centre. I'd be surprised if the bags are not designed to be use several time over.

I use empty winebags which I empty of wine by pouring it into my stomach. I cannot speak for C41 developer but I have kept Xtol fresh in these bags for well over a year. The only problem I have found recently is that the winebag manufacturers now tend to make bags where the dispenser tap is not designed to be removed. In the U.K. one supermarket still sells the older type bags which are silvered on the outside and have removable dispensers but this is of no relevance to the U.S. unfortunately.

It is literally a case of "suck it and see" or buy a bag, pour it and see

pentaxuser


pentaxuser

Phototherms feed from the bottom of the bottle, and so the liquid disturbance will really be only the downward movement. I won't have to open it after I connect my tubing and spay the the gas.

Assuming the protection spray is working, how long can I expect C41 dev to last?

Just got my final chemicals from Unique Photo! The fix was on back order.

So deterioration depends entirely on the rate of innate chemical decomposition as no air after you spray will enter? If this is the case then it needs a colour chemical engineer to respond. I think we have one somewhere a little to the North West of where you are

pentaxuser

WHY do you want to make 5 Gallons? Developer comes in 5 Liter batches dirt cheap from Unique (14 bucks)
From Alaris:
Once you open the original container, the chemicals are
exposed to oxygen that will react with the chemicals and
gradually cause them to deteriorate. This is especially true of
developers. Oxidation occurs to some extent even if you
immediately reseal the container. To reduce the effects of
oxidation, store solutions in amounts that you can use at one
time. For example, if you open a 10-gallon-size container,
mix the entire amount, and then store the solution in closed
one-gallon containers. Each time you need more chemicals,
open a bottle and use the entire amount. The remaining mix
stored in separate containers is not exposed to air.
When you store solutions in plastic bottles, fill the bottle
close to the top and then squeeze the bottle gently before you
cap it to raise the chemical level to the top of the neck.
Flexible plastic containers minimize oxidation because air
is excluded when the plastic container collapses as chemicals
are removed. Store drums upright to expose as little surface
area to the air as possible.
Length of Storage Time—For best results, do not use
solutions stored longer than the times given .

See the Z-131 manual on Alaris website, basically you have 6 weeks to use developer in full glass bottles once mixed. I have stored in full bottles longer than that.

Nitrogen blanket would work, butane/propane has some obvious drawbacks.

Kodak recommends 1 shot with developer with rotary processors. The bleach and fixer can be replenished.

The protection spray I got is argon.

dmr said:

The protection spray I got is argon.

Click to expand...

I thought that here with protection spray the "propriatory" single-use cans were meant. But yes, in proper meaning one can use a variety of gases.