Old Neofin Blue

[Alan Johnson]

I bought some phials of Neofin Blue estimated by the seller to be about 30 years old. This is not verified as I don't know when packaging was changed from phials to the present small bottles.
Agfaphoto APX 100 at EI=100 was developed for 14 min 20C (as per massive development chart) in a phial of Neofin Blue diluted to 500ml (faint straw color, pH>12).
The density of the negatives obtained (see pic) was normal, in fact it looks the same as APX 100 developed in a newer bottle of Neofin.
So these phials have a long shelf life.

Here is the msds for Neofin Blue:
http://www.freestylephoto.biz/pdf/msds/tetenal/Neofin_Blue.pdf

In my experience the phials give a long shelf life for a metol based developer in absence of air or with very little air.I have had a glass bottle of Perceptol pH~7 last 3-5 years and a bottle of some Gainer's Metolal pH~14 around 1 year.My theory is that normally metol would hydrolyse to methylamine sulfonate and hydroquinone, but when hydroquinone is present in the solution this reaction does not run.Thus HQ is a preservative vs hydrolysis. This theory would only apply if they changed the formula since Crawley's early work, he wrote, BJP Jan 6 1961 p11 "Neofyn blue ... appears to be a pyrocatechin based surface developer..."

Thanks for comment.

 

[miha]

Years ago I was able to successfully develop a roll of APX 400 in Neofin Rot/Red - a higher-speed version of the Blau/Blue - which was at least 10 years old at the time and very dark in appearance.

 

[Gerald C Koch]

The developer in sealed glass vials should have a very long life since oxygen cannot get to it. However newer packaging in plastic bottles has a limited life.

 

[miha]

Are you saying that Neofin comes in plastic bottles now? I think it comes in glass bottles with plastic screw on caps.

 

[Alan Johnson]

The developer in sealed glass vials should have a very long life since oxygen cannot get to it. However newer packaging in plastic bottles has a limited life.

I expect the material of the container is a factor, but still consider that Metol hydrolysis is a factor as well.
If metol did not hydrolyse, Beutler developer, for example could be made up as a single solution.There could be a metol based clone of Rodinal on the market, as suggested by Gainer.

 

[pentaxuser]

Thanks for comment.

The third one which I assume is HMS Belfast is a superb picture both technically and compositionally. How long ago was this taken?

Thanks

pentaxuser

 

[Alan Johnson]

Thanks Pentaxuser,
Yes it is the Belfast with Tower Bridge just visible in the background, the area near London Bridge Station is a happy hunting ground for photography.It was taken 2 days ago using a yellow filter.APX 100 works well with Neofin Blue.

 

[Gerald C Koch]

The last time I purchased many years ago Neofin was in plastic bottles with a plastic cap. Glad to see that they have switched to glass. However the plastic cap is now the weak link.

 

[chip j]

Thanks for posting pics---it brought back strong memories of when I used lots of the solid glass vials w/Panatomic X.

 

[Murray Kelly]

In my last year at Med school I had some FX-2 done up in 10ml glass vials in the Path Lab. That was 1961. I still use one when the whim takes me and it works just fine. Last was in 2007 IIRC. Each vial has enough for 250ml working solution and every time I have to look up and recalculate the pot. carbonate required!

 

[Alan Johnson]

Thanks for comments,now the conclusions are revised.
I did not make clear that my experience has been that metol based developers (without hydroquinone) apparently degrade over time in sealed glass bottles with very little air.
This applied to Perceptol (3-5yrs),Gainer's Metolal (~1yr) and Thornton's 2 bath part A (3-5yrs).
The weights of the the small amounts of oxygen left in these bottles would be very small in relation to the weights of developer ingredients so the developers would not have degraded by oxidation (unless Jerry Koch's Plastic Cap theory is true).
So the Neofin phials seemed to be a special case in lasting so long.
But now thanks to Murray reporting his results with FX-2 I think I may have been wrong that metol hydrolyses, and in fact oxidation was what occurred.
Time to take out a patent on a variation of Gainer's Metolal then.

 

[Kevin Caulfield]

As a sidelight, interestingly according to the current MSDS it appears to contain Phenidone in addition to Metol/HQ. So here it would seem we have a commercial example of this triple combination we've discussed before (which still puzzles me).

Another commercial example of this was Acutol-S, which is FX-15.