Dissolving Xtol 2x

ekjt · Jul 27, 2005

Some people in other discussion forums have been writing about dissolving a 5 liter pack of Xtol in only half of the volume for convenience.
I have now twice tried in, and ended up diluting it up to full 5l to get it dissolved. I used ion-exchanged water, magnetic stirring and several hours.
I'm also worried about possible oxidation caused by strong agitation for extended periods. Anyone here who is successfully doing it? Yes I know it's against the instructions, but so is diluting it 1:3 too.

psvensson · Jul 27, 2005

I've mixed Xtol that way, and it worked fine. However, you're getting close to the limit of sulfite solubility, and it may precipitate if the solution gets cold. You probably have about 160g/l of sulfite in double-strength Xtol. I once ruined a 200g/l solution of sulfite by putting it in the fridge.

GeorgesGiralt · Jul 27, 2005

Hi !
I had some success dissolving Xtol very fast (in the specified volume) using hot water at about 50 ° C (I boil all tap water used for making stock solutions, so having hot water is easier)
Maybe this will help dissolve all the chemicals in the 2.5 L....

ekjt · Jul 27, 2005

Definitely, but according to Kodak datasheet, the water used for mixing should not be warmer that 30 C or 85 F. Maybe it doesn't really matter. Is there any sensible reason for this limitation?

Neal · Jul 27, 2005

Dear ekjt,

I store Xtol in combination of 500ml and 250ml bottles (these sizes are convenient for the tank sizes I use most often). I keep them in a box and they really take up very little room. It is very convenient to simply grab a bottle and know it has already been measured for use.

Neal Wydra

Gerald Koch · Jul 27, 2005

Historically Kodak recommended 125 deg F (50 deg C) for all their other developers. If they have specified 85 deg F for Xtol then there is a good reason for using the lower temperature.

srs5694 · Jul 27, 2005

Gerald Koch said:
Historically Kodak recommended 125 deg F (50 deg C) for all their other developers. If they have specified 85 deg F for Xtol then there is a good reason for using the lower temperature.

XTOL is chemically quite different from most other commercial developers; it's based on ascorbic acid and phenidone, vs. hydroquinone and metol for most others. (There are a few exceptions, like Rodinal, which uses p-aminophenol hydrochloride.) In any event, XTOL's composition is such that it can be mixed at room temperature. That's not to say that it must be mixed at room temperature. I suspect that Kodak recommends room-temperature mixing for XTOL simply as a marketing measure; it's a desirable feature for many photographers. I've seen some suggestions that mixing XTOL at higher temperatures can be helpful because it reduces the time required to mix it, which can decrease the amount of air you mix into the solution, thus decreasing the risk of encountering "XTOL sudden death." This is just speculative, though; as with so many things, the Internet is full of rumors and speculation about XTOL.

Tom Hoskinson · Jul 27, 2005

I have mixed phenidone, and ascorbic acid into stock solutions (some in Propylene Glycol and some in Tea - no water!). They are still going strong after a year.

The mixing temperatures with Propylene Glycol were 140 F to 150 F. The TEA (Triethanolamine) mixing temperatures were 150 F to 240 F.

I use little or no sulfite in my stock concentrates.

john_s · Jul 28, 2005

GeorgesGiralt said:
Hi !
I had some success dissolving Xtol very fast (in the specified volume) using hot water at about 50 ° C (I boil all tap water used for making stock solutions, so having hot water is easier)
Maybe this will help dissolve all the chemicals in the 2.5 L....

I have done the same to get it to dissolve in 2.5L, except that I didn't actually measure the temp, but it was definitely hotter than 85degF. The Xtol is still working after 6 months. Maybe any damage caused by the higher temp is negated by the higher concentration which should make longer term storage more successful.

Tom Hoskinson · Jul 28, 2005

john_s said:
...Maybe any damage caused by the higher temp is negated by the higher concentration which should make longer term storage more successful.

Should be no damage to the developing reagents from these mixing temperatures.

Degradation by oxidation of the phenidone (or phenidone derivatives) and the ascorbates in the aqueous solution is another matter.

msage · Jul 29, 2005

Why not get a 5L jug? I work in a lab and we get some chemicals in 5L containers. I save them, clean them out and give them to customers who ask the $64 question "Is 5L's the same as one gallon?"
Michael

Dissolving Xtol 2x

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