Mixing XTOL stock

[peter_trenchard]

<p>I have recently started to use Xtol again after a lapse of 10 years. While mixing the 5 litre stock it appeared that there was a large quantity of insoluble particles. I filtered the mix and stored it in clear glass winchester bottles but within 24 hours the particles reappeared as a precipitate. These were denser that the developer and settled like tiny snowflakes onto the bottom of the bottle. Before use I filtered it again and the developed neg was OK. The mix was done as per instructions and the water was ordinary tap water which is quite soft, no carbonates.<br>

Has anyone else had this happen? I have been mixing powder film and paper developers, mainly Ilford, Agfa and Kodak, for more than 35 years and have never seen anything like this.</p>

[jim_norman4]

<p>XTOL has a problem with cold temperatures (mixing or storage) or water in the mix with certain minerals. To isolate the problem, mix up your next batch with distilled water.</p>

[bob_sunley]

<p>Kodak publish specs for mineral content in water for mixing chemicals. You should be able to get information from your water utility on the tap water contents, and then compare the two.</p>

<p> </p>

[thirteenthumbs]

<p>I use a 1/4 inch diameter acrylic rod to stir the powders in, in order. At the end of part A there is always some clumps that did not dissolve and I crush them against the bottom of the mixing container until all the powder and clumps are fully dissolved then I add part B and do the same.</p>

<p>After part A appears to be dissolved let the solution stand without further stirring for 2 to 3 minutes, crush the clumps, stir, let stand, repeat. Once part A is dissolved do the same with part B. The total mix time will be in the 10 to 15 minute range.</p>

[Didier Lamy]

Use a magnetic stirrer, expensive but makes the dissolution much faster, and you are not stuck in front of your vial. Demineralized water helps too, and the car battery grade is cheap (2-3 euros/5 liters)<div></div>

[peter_trenchard]

<p>Thanks for your comments. The problem is not in the mixing as my normal method has worked OK for the last 35 years with many different powder developers. The precipitate only occurs with Xtol so I am assuming from what you have said the formulation of Xtol being ascorbic acid based is much fussier about the quality of the water than other developers. For my next mix of Xtol I will used as suggested by Didier deionised water which is de-mineralised and much cheaper than distilled water, about £4 for 5 litres from our local motor accessory shop.<br>

Thanks again,<br>

Peter </p>

[hernan_zenteno]

<p>I saw some particles in my Xtol developer but I used it without problem. Did you see any problem in film developed in it?</p>

[pc_b]

<p>I used to mix Xtol in cold tap water (over the season varying from quite soft to medium hard) and later in cold battery grade water. My experience/observation was: it took up 10 minutes to dissolve part A (almost constantly stirring and crushing flakes), then about 5 min until part B had dissolved, too. Nerve-wracking.</p>

<p>Then I started using water at about 30°C (battery water container in warm water bath) and both parts dissolved in less than two minutes each! Almost no flakes.<br>

I never filtered Xtol before use. Fear of getting the ratios out of ballance.<br>

Guess how I mix up Xtol now...</p>

<p>I am used to observing cloudy 'stuff' in week/month-old Xtol bottles (glass, full to the brim) which always dissolves instantly as soon as I go 1+1 or more. Even 12+ month old bottles worked as if recently mixed. (But I always do a test strip to keep my blood pressure down in the healthy range.)</p>

<p>And no: every powder chemical (mix!) is different from all others. There is no 'should be like all other...'.</p>

[Didier Lamy]

I have occasionnally noticed insoluble crumbs in the final mix, even with demineralized water. I filtered them out with coffee filters (quite messy with 5 liters), no subsequent problem with films processing, I am not sure that it did something useful, but I felt reassured. I suspect that there is some diversity in Xtol batches .