RA-4 Tetenal Protectan

Bumba · Nov 16, 2020

Hi, I don't process in high volumes so usually have chemicals sitting around for a few months. I use the Kodak RA RT and mix up 5 litres at a time in one go. I was wondering if anyone has any experience with Tetenal Protectan and if it works well on a long term basis (around 6-8 months). I was thinking about mixing 2.5 litres at a time and keeping the concentrates in half filled bottles with Protectan. Which would give me better shelf life and fresh chemistry? Thanks for any help

pentaxuser · Nov 16, 2020

Bumba I take it that you mean you'd fill bottles completely initially but continue to use those bottles as they are emptied and fill with Protectan I don't know the answer but if the posts in reply are favourable towards Protectan. I'd consider cheaper versions of heavier than air gases. Gas that protects wine tends to be cheaper. You pay to an extent for the name Protectan

Personally I'd tend to decant the 2.5 L into smaller bottles that you can fill to the brim

pentaxuser

Donald Qualls · Nov 16, 2020

I've used butane lighter fuel as blanket gas. It's enough heavier than air to stratify nicely, and can even dispense as short-lived liquid which will displace air more completely as it boils off. And it's cheapish; the cans look small, but the butane expands by a huge ratio from the liquid stored in the can.

Yes, it's flammable. Don't use a candle safelight near it.

moofy · Nov 17, 2020

Welder's argon is cheap and available in small cylinders. Glass marbles also fill up volume and are non-reactive.

halfaman · Nov 17, 2020

Donald Qualls said:
I've used butane lighter fuel as blanket gas.

That is more or less what Tetenal Protectan is.

Donald Qualls · Nov 17, 2020

halfaman said:
That is more or less what Tetenal Protectan is.

Does it carry a "Flammable" label? If not, it's probably a chloro-fluorocarbon similar to R-134a refrigerant.

halfaman · Nov 17, 2020

Donald Qualls said:
Does it carry a "Flammable" label? If not, it's probably a chloro-fluorocarbon similar to R-134a refrigerant.

Check it by yourself.

https://www.digitaltruth.com/products/tetenal_msds/protectan-MSDS.pdf

Donald Qualls · Nov 18, 2020

Yep, butane, propane, and isobutane (probably mixed to control the vapor pressure). Little or no advantage over buying lighter butane at the local smoke shop, or butane intended for a portable stove at a sporting goods or retaurant supply store -- all of which are likely a fraction of the cost.

Lighter butane has a fairly easily operated pressure-actuated valve and dispenses liquid when held valve down, which makes it easy to use in this application.

Bumba · Nov 18, 2020

Thanks for all the help everyone. How decent is the shelf life when using gas to protect chemicals? Could I keep concentrates fresh for 6 months possibly?

Pentaxuser I keep my working solutions in wine bags and that seems to be working really well but I can't help feel that my chemistry might have also lost some activity. I mixed this current batch at the start of the year. I might have to mix some new chemicals and see if there's a difference

138S · Nov 18, 2020

Bumba said:
Which would give me better shelf life and fresh chemistry?

Of course !!! The concentrates that remain in the openned bottles, if well filled/protected with inert gass, they will be preserved almost as is the boottles were sealed. Once you mix the different components of CD or Bleach-Fix a fast degradation will start, they are shipped in parts for good reasons.

If you use only half a bottle and then the single harm would be done by air that contains oxygen, if preserved with Protectan (or butane...) then not only air is displaced, if some oxygen remains in the bottle protectan/butane won't allow the oxygen reach the chem, as butane is denser than air then a layer of inert gas lays on the liquid displacing the oxygen up.

Presently I mostly use the method you describe for E-6 chem, and I used the chem even one year after unsealing the bottles with perfect results, with the chem protected with inert gas. I had used it for C-41, but never I reached 1 year after unsealing, but recall six months.

As always, after a long storage always check the chem before using it if important images are in the middle. Start with a single roll, or shot some two frames of a roll and (in darkness) open the camera and cut those frames to make the test, you will be able to use the rest of the roll if properly cutting the edges of the film lead. If you only processed 2 frames of a roll for the test then you may also reuse the chem, no exhaustion will be noticed...

pentaxuser · Nov 18, 2020

Bumba said:
Thanks for all the help everyone. How decent is the shelf life when using gas to protect chemicals? Could I keep concentrates fresh for 6 months possibly?

Pentaxuser I keep my working solutions in wine bags and that seems to be working really well but I can't help feel that my chemistry might have also lost some activity. I mixed this current batch at the start of the year. I might have to mix some new chemicals and see if there's a difference

It depends what you mean by "working solutiions. If that really means stock solutions then I do the same as you which is to use winebags for the likes of 5L of Xtol and that definitely lasts longer than 6 months in such bags

I have never done a test of whether full bottles of developer can last longer than its equivalent in winebags but I suspect that full bottles and used in one go may well last longer. By full I mean to the very rim and then tightly screwed down so there is no space for air. Such bottles need to be used completely in one go. So for instance and in my case that would be 250ml each time for Xtol or 125ml and then diluted immediately prior to use. it is of course more trouble to do it this way and not worth the effort compared to winebags if you use all 5L in say a year

Winebags as they have a dispenser will, I imagine, inevitably allow some air in the long run

pentaxuser

thuggins · Nov 18, 2020

I ended up getting a bunch of 100ml bottles and aliquot the remaining concentrate while mixing the first batch. Not only does is prevent oxidation, the remaining batches are very easy to mix.

pentaxuser · Nov 18, 2020

thuggins said:
I ended up getting a bunch of 100ml bottles and aliquot the remaining concentrate while mixing the first batch. Not only does is prevent oxidation, the remaining batches are very easy to mix.

So that's decanting 5L of the likes of Xtol/D76 into 50 bottles, I think That's a lot of bottles. My experience is that 100ml bottles tend to hold close to 120-125 which would be fine for 1+1 in a Jobo 35mm tank but presumably with the likes of Paterson tanks being 300ml then 3 bottles of stock is fine but if its 1+1 then that leaves 50ml spare from 2 bottles, doesn't it?

Thanks

pentaxuser

138S · Nov 18, 2020

pentaxuser said:
So that's decanting 5L of the likes of Xtol/D76 into 50 bottles, I think That's a lot of bottles. My experience is that 100ml bottles tend to hold close to 120-125 which would be fine for 1+1 in a Jobo 35mm tank but presumably with the likes of Paterson tanks being 300ml then 3 bottles of stock is fine but if its 1+1 then that leaves 50ml spare from 2 bottles, doesn't it?
Thanks
pentaxuser

I understand he speaks about 100ml bottles filled with concentrates, not with stock solution, in that way no protective gas is required, and when you have 8 rolls you open a 100ml bottle of each concentrate to make 500ml stock, this is also a very good solution, after re-sealing the concentrate in 100ml dose when you open a bottle you use it...

For that way with the 2.5L kit we need 25 bottles of 100ml capacity...

halfaman · Nov 19, 2020

138S said:
He speaks about 100ml bottles filled with concentrates, not with stock solution, in that way no protective gas is required, and when you have 8 rolls you open a 100ml bottle of each concentrate to make 500ml, this is also a sound solution.

This is how I keep color developer concentrates (just CD part) or working solutions and it works great. Every time I open a bottle liquid looks like new and for more than one year.

Bumba · Nov 19, 2020

Thanks everyone for the help. I think I'll give the Protectan a try as it's still available i the UK and not too expensive. Just wish Kodak would give a more accurate time span for their chemicals as it seems 6 weeks is a massive understatement for ra4

RA-4 Tetenal Protectan

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