Pyrocat-HD ?precipitate

[Hedd-wyn]

I bought Pyrocat-HD in glycol, the large 500ml size to make 10 litres, in October of 2019. Upon receiving it, I immediately decanted both Part A and Part B into clean brown glass 500ml bottles and placed them in a cool dark cupboard. They remained undisturbed until today, March 18/20, after I had finally used up my remaining Xtol. Upon removing the bottles, I noticed that Part A had separated into 2 distinct layers. The upper layer, which occupied about a quarter of the bottle, was completely clear while the lower layer was completely opaque. Is this normal? Has anyone else experienced this separation? Before I shake the bottle to reconstitute the solution and try it out on some test negatives, I would like to know if this will be problematic. Thanks

[mpirie]

I've seen this separation of Part A before in a couple of kits from PF.

Although it's disturbing to see, it does not appear to have any adverse effect on the action of the developer.

In fact, my next bottle has the same separation and i've already tested it with no ill effects.

Mike

[Hedd-wyn]

Well, that's good to know. Thanks for the prompt reply. This kit was from Photographers' Formulary as well. I notice that in other threads that Part B can precipitate out because of low storage temperature. I wonder if this is a similar issue, although the opacity doesn't look like crystal precipitation. In the case of Part B it was suggested to simply heat up the solution and redissolve the crystals. I may give this a try with the Part A solution and see what transpires. With everything in lock down because of the Covid-19 virus, the darkroom seems to be the safest place to spend one's time sorting things out.

Hedd-wyn

[mpirie]

I haven't seen Part B with precipitate, but certainly Part A.

My darkroom does get very cold at this time of year and i've seen the air temp at around 4˚C so warming the bottles up before a session would do no harm at all.

Mike

[Hedd-wyn]

Problem solved. I filled up a mixing bowl with the hot water tap running into it and immersed my 500ml bottle of Part A. My hot water comes out of the tap at 128F or 53C. I left the bottle in to equalize the pyro with the waterbath for about 10 minutes, the hot water running continuously and periodically gave the bottle a very vigorous shaking. The opacity completely disappeared and left me with a very clear Part A with no evidence of precipitation. I ran 2 test negatives with the newly reconstituted Part A and the negs came out fine. I guess one has to take care and not store the solutions where they will get chilled.

Hedd-wyn

[mpirie]

That's very interesting Hedd-wyn......i must try warming my Part A up too to see if it gets rid of the precipitate.

Easier to keep the solution in the house than to keep the darkroom warm!

Mike

[Hedd-wyn]

Hi, Let me know if this works for you as well. I am going to contact PF to see if they have any insight as to what exactly is happening in the solution when it gets cold.

Hedd-wyn