Tetenal fixer and developer........tablets

[gone]

Freestyle sent me an email on this new (to me) Tetenal fixer and developer that comes in in tablet forms. They're saying it has a shelf life of 4 years.

https://www.freestylephoto.biz/105500-Tetenal-Parvofin-Film-Developing-Tabs

 

[AgX]

We have discussed such tablets at their introduction to the amateur market.

Do you want to discuss their longevity?

 

[John Wiegerink]

We have discussed such tablets at their introduction to the amateur market.

Do you want to discuss their longevity?

Four years sounds pretty good to me. I’m curious to see how they work. Why no stop bath tablets? JohnW

 

[Truzi]

I got the mail too. I'm intrigued - might try some.

 

[pentaxuser]

As tablets I am a little surprised at only 4 years' life . I had thought that effectively a tablet would be the equivalent of powder compressed into tablet form but I suppose that to maintain this form there has to be something else there and it may be this that causes life to be limited to 4 years
On the other hand might it not be possible to coat it with the same kind of cover that medicinal tablets use that dissolves harmlessly but forms a barrier to air until it is mixed with water ? May be even this covering does not last longer than a guaranteed 4 years

pentaxuser

 

[mshchem]

4 years unopened. Buy a bottle of Rodinal.

 

[Moose22]

Four years sounds pretty good to me. I’m curious to see how they work. Why no stop bath tablets? JohnW

Because stop bath is cheap as all get out.

Kodak indicating stop bath is like $7 for enough to make 8 gallons of the stuff.

 

[pentaxuser]

We have discussed such tablets at their introduction to the amateur market.

Do you want to discuss their longevity?

AgX, as you will see from my post I am curious as to how 4 year's life was established when I imagined that as tablets their life if kept in a bottle might be almost indefinite like powder. As I said it maybe that the covering on a tablet that protects it is not as good as a powder in a sealed packet

Thanks

pentaxuser

 

[BobUK]

I you do get round to buying a bottle of the tablets, it would be a nice experiment to put three or four in a labelled test tube. Fill the tube with a squirt of Tetenal developer preserver gas, or lighter fuel butane.
Seal it up and keep it for five or six years before using the tablets. They might last longer than Rodinal if preserved in gas.
If you have youth on your side and cash to spare, an even longer experiment is feasible.

 

[mshchem]

AgX, as you will see from my post I am curious as to how 4 year's life was established when I imagined that as tablets their life if kept in a bottle might be almost indefinite like powder. As I said it maybe that the covering on a tablet that protects it is not as good as a powder in a sealed packet

Thanks

pentaxuser

Tetenal made this product before. I'm sure it would work, I'm not a customer but this isn't a new idea.

 

[AgX]

A coating was not intended and is not applied as far as I know.

With pressed substances one may argue, that by pressing the powder they particles are protecting themselves in contrast to a heap of powder. A contrary effect is much harder to argue on.

 

[pentaxuser]

Thanks Agx. The reason for 4 years might just be that Tetenal like other producers of chemicals such as developer are conservative about longevity. As I recall things the producers of Rodinal and HC110 do not state the length of their respective lives as anything like as long as most users find to be the case from experience

pentaxuser

 

[gone]

4 years unopened. Buy a bottle of Rodinal.

I hope it still works this way, mine is getting a nice caramel color. 4 years as the expected shelf life for tablets seems short, but that may just be their SWAG since it's new. It may last much longer, they're going to under rate it initially.

It would be easy to mistake this for OTC medicines too, so I'd make sure that everyone knew that a Tums looking thing might be photographic developer.

 

[mshchem]

I don't take chances with chemistry. A bottle of Rodinal is 12 bucks, that's for 500mL enough for a bunch of film. I dumped a partial bottle of Rodinal a couple days ago that's been open 3 years. It was still working fine, but I keep fresh Rodinal on the shelf Adox makes good Rodinal and the container is genius.
XTOL keeps well too. Unfortunately XTOL doesn't change color when it's old. Tetenal has a great track record, they wouldn't be selling this if they had doubts.

 

[John Wiegerink]

Because stop bath is cheap as all get out.

Kodak indicating stop bath is like $7 for enough to make 8 gallons of the stuff.

That's true about the cheap cost of stop bath. It's even cheaper than using household vinegar. I would think that if I were using these tablets that a tablet of stop bath would be handier and easier than liquid. I was just curious anyway. JohnW

 

[mshchem]

That's true about the cheap cost of stop bath. It's even cheaper than using household vinegar. I would think that if I were using these tablets that a tablet of stop bath would be handier and easier than liquid. I was just curious anyway. JohnW

Citric acid is what Ilford uses, odorless and very cheap on Ebay, used as a food additive so it's safe to have around, lasts forever.

 

[Vaughn]

Take One and See Mt. Fujiyama

 

[tokam]

Because stop bath is cheap as all get out.

Kodak indicating stop bath is like $7 for enough to make 8 gallons of the stuff.

A quick look at the specs on the Freestyle page would indicate that the tablets are for single use applications, (max 2 x 36 exp films per developer tablet).

The obvious use case for these products is while travelling - just carry the tablet chems plus a dev tank and a way of measuring solutions. No liquids required on flights etc.

No need for stop bath as the fix solution is unlikely to be overwhelmed by the developer. Use once or twice and toss it.

At Freestyle's prices this isn't the cheapest way to process films but under certain circumstances could be the best way to go.

 

[Moose22]

That's true about the cheap cost of stop bath. It's even cheaper than using household vinegar. I would think that if I were using these tablets that a tablet of stop bath would be handier and easier than liquid. I was just curious anyway. JohnW

For you it might be. But, then, you can just stop with water and be fine if you want the cheapest and simplest. What's the REAL use for these things?

As tokam says, there might be a reason to use these when traveling, which is an excellent use case, But if that's the case you're using fixer tabs and making fixer in small amounts anyway, so you aren't worried about extending fixer life.

If you want to use them at home, it's not much different. You want to intermittently use small amounts, and stop is the least critical thing in the process. And cheap. My guess is that Tetenal figured that there's not enough of a market for stop tablets to be worth the hassle and product development expense.

 

[John Wiegerink]

For you it might be. But, then, you can just stop with water and be fine if you want the cheapest and simplest. What's the REAL use for these things?

As tokam says, there might be a reason to use these when traveling, which is an excellent use case, But if that's the case you're using fixer tabs and making fixer in small amounts anyway, so you aren't worried about extending fixer life.

If you want to use them at home, it's not much different. You want to intermittently use small amounts, and stop is the least critical thing in the process. And cheap. My guess is that Tetenal figured that there's not enough of a market for stop tablets to be worth the hassle and product development expense.

Your probably right about "not enough market" for the stop tabs. I only use a water stop anyway so I'm as cheap as I can get. Prints are a whole different can of worms. JohnW

 

[Richard Man]

Here's an example of the Pavrofin developer tabs. Not example of anything other than "it develops film". It's high noon, the wind is a thousand mph, there were sands in my teeth, and in my eyes. The film is Acros 100. I am standing next to a partial whale skull. I am a small person, but that skill's tip is probably about 7 feet high (someone asked if I brought the skull down to the beach to photograph....)

 

[bluechromis]

Jay Defehr mentions a dry tab type home-brew developer:
https://www.facebook.com/groups/117148252245097/search/?q=Grametol

He also worked on a PC type dry developer called Honey Balls made in a hardened ball of honey, like sugar candy. He said the developer performed very well. But the drawback was that it took a long time to dissolve at 20 C.