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  1. #491

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    Quote Originally Posted by Alan Johnson View Post
    As well as that test for oxidation I hope to do a test to find if phenidone/dimezone-s will hydrolze by reaction with the water of crystallization in one of these developers.
    To speed up the reaction it is intended to place full sealed bottles of concentrate on top of a hot water tank ~40C.
    Hydrolysis of phenidone produces phenylhydrazinopropionic acid: C6H5.N.CH2.CH2.CO.NH +H2O -> C6H5.N(NH2).CH2.CH2.CO.OH
    Not a lot of people know that.
    I want to publicly express my appreciation to Alan for running these tests.

    BTW, in my prior posting of time-increases based on colour, I incorrectly assumed a linear drop in activity. As ascorbate is destroyed, activity drops slowly at first, and then faster. So I revised my estimates:

    clear -------------> 0%
    yellow -----------> 3%
    dark yellow -----> 8%
    orange ----------> 15%
    dark orange ----> 30%

    Alan is also concerned about water of crystallization (in the metaborate) hydrolysing the Phenidone. Coincidentally, I recently tried developer 214D modified by replacing the sodium metaborate with TEA. The interesting part was the amount of weight-loss due to evaporation during hot mixing: 214D loses about .30 g in the 1-liter formula. The TEA-version only lost .05 g, and my temperature was a little higher. That tells me that either (1) the metaborate-version loses much more water because more water is present, or (2) TEA prevents PG from evaporating.

    If anyone cares to try it, I changed 214D to use 2.8 g of TEA-99% and 11 g of PG. The resulting concentrate is at the same 18 g/litre and yields the same pH of 8.08. But it develops faster. TEA seems to cause faster development than metaborate, even at the same pH. Anyway, 214D is similar to D316, and D316 survived a severe one-year test and did well in my extensive tests, so I'll stay with that formulation. TEA must wait.

    Mark Overton

  2. #492

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    It now seems that I won't be able to run the tests mentioned as there seems to be a chemical reaction occurs within D-316 at 40C.

    In an unplanned experiment I left a bottle of D-316 on top of a hot water tank for about 2 weeks. The D-316 temperature varied between ~35~50 C, say 40C average.Upon noticing it was there I opened it,still hot, whereupon it foamed and bubbles came out of the solution.2 days after it had cooled to room temperature I noticed that it had formed tiny suspended crystals in half the bottle, see pic.
    IDK if this has something to do with borate-glycol compounds being formed.

    Other news- A good source of dimezone-S in the UK ,and maybe Europe, is www.moersch-photochemie.com
    I sent them an email asking if they knew where I could get 50 grams,received a quote, paid by paypal, and 2 days later it arrived in the UK.
    Because the shipping cost to the UK is less, it's cheaper than buying from Photoformulary or the other supplier (TechChem?) in the US.
    Attached Thumbnails Attached Thumbnails D-316 14  days 40C.jpg  

  3. #493
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    Quote Originally Posted by Alan Johnson View Post
    IDK if this has something to do with borate-glycol compounds being formed.
    How would these be gaseous ? Very odd indeed ...
    Quote Originally Posted by Alan Johnson View Post
    Other news- A good source of dimezone-S in the UK ,and maybe Europe, is www.moersch-photochemie.com
    If you click on the link "shop" on the top left, then click on "Rohchemie" on the bottom of the left bar, you land on a page which shows where Moersch gets his raw chemistry from: Fototechnik Suvatlar. Does that name sound familiar?
    Trying to be the best of whatever I am, even if what I am is no good.

  4. #494

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    Yes, thank you, they appear to wish to distribute via Moersch:

    http://www.alternativephotography.co...chnik-suvatlar

  5. #495
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    Quote Originally Posted by Alan Johnson View Post
    Yes, thank you, they appear to wish to distribute via Moersch
    I never had a problem getting stuff from Suvatlar directly. It's not like you could order raw chems from the Moersch shopping portal anyway or that Moersch would provide additional services. Note that the email address listed is for Suvatlar himself, and it's a generic mail provider, not some domain under control of Moersch.
    Trying to be the best of whatever I am, even if what I am is no good.

  6. #496

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    Quote Originally Posted by Alan Johnson View Post
    In an unplanned experiment I left a bottle of D-316 on top of a hot water tank for about 2 weeks. The D-316 temperature varied between ~35~50 C, say 40C average.Upon noticing it was there I opened it,still hot, whereupon it foamed and bubbles came out of the solution.2 days after it had cooled to room temperature I noticed that it had formed tiny suspended crystals in half the bottle, see pic.
    Your picture is identical to the crystallization that I've often seen: The solution collapses, producing a separated liquid and cream. I've known that D-316 is close to the edge of the crystallization-cliff, because I've seen white smudges of the start of crystallization on the bottom of a beaker when mixing it hot (85C). Your test evidently pushed it over the cliff. Congratulations. Actually, this is good news because it gives us a way of stressing a concentrate, and the same test can be done with the final developer. I suspect that the ratio of sodium metaborate to ascorbic acid largely determines vulnerability to crystallization, and the latest developer, 214D, has a lower ratio, so it's hopefully more robust.

    Yesterday, I shot and developed an important roll using Delta 400 and 214D. Results are beautiful. Here's an example taken in mediocre indoor lighting at box-speed:

    Click image for larger version. 

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    Mark Overton

  7. #497

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    I noticed that Internet Explorer (IE) sharpens images a little. That makes the picture in my prior posting look sharper and grainier. For this and any other scans on apug, I suggest that IE users right-click the image, save it to a file, and open the file in Windows Picture and Fax Viewer (or a photo-editor). Then you'll see what's really there.

    I use Firefox at home, so I didn't notice this sharpening until I came to work. I said to myself, "I don't remember it being that grainy"...

    Mark Overton

  8. #498
    Rafal Lukawiecki's Avatar
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    Mark, now that you have done your fairly involved development work on an XTol-like concentrate, have you any feelings as to what would be the closest-or-better, regular, non-concentrated version, ready for an immediate use, after mixing?
    Rafal Lukawiecki
    See rafal.net | Read rafal.net/articles

  9. #499

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    Quote Originally Posted by Rafal Lukawiecki View Post
    Mark, now that you have done your fairly involved development work on an XTol-like concentrate, have you any feelings as to what would be the closest-or-better, regular, non-concentrated version, ready for an immediate use, after mixing?
    Rafal, a simple method would be to mix the formula for 214D directly into water, without the propylene glycol. That would be:

    Water ........................................ 800 ml
    Sodium sulfite ........................... 45 g
    Sodium metaborate 4 mol ........ 1.8 g
    Ascorbic acid ............................ 4.2 g
    Dimezone S .............................. 0.08 g
    Water to .................................... 1 litre

    Propylene glycol changes dev-time a little, so removing it means you would need to adjust time. But the big problem with all PC formulas like this is that the Fenton reaction slowly destroys the ascorbate. That means it will last only a few weeks. Kodak solved that problem by adding DTPA to XTOL. But DTPA is difficult to find for ordinary people. Another way to fix this problem is to not put ascorbic acid in it, giving this formula:

    Water ........................................ 800 ml
    Sodium sulfite ........................... 45 g
    Sodium metaborate 4 mol ........ 1.8 g
    Dimezone S .............................. 0.08 g
    Water to .................................... 1 litre

    This solution will probably last a long time, at least 6 months. But to use this developer, you need to add ascorbic acid separately to your beaker. That's an extra step, so it's not quite "ready to use" which you asked for. If you don't want to weigh the ascorbic acid, it might be easy to measure it with a small measuring spoon.

    Back in July 2012, I found that this formula gave the same development-times and same quality as XTOL:

    Water ........................................ 800 ml
    Sodium sulfite ........................... 90 g
    Sodium metaborate 4 mol ........ 6.7 g
    Ascorbic acid ............................ 8.5 g
    Dimezone S .............................. 0.2 g
    Water to .................................... 1 litre

    This acted like a clone of XTOL. It was mixed in propylene glycol, so direct-to-water times might change. It's problem was crystallization, so it's not suitable for propylene glycol. But you can also add the ascorbic acid separately with this formula.

    Finally, ascorbic acid can be replaced with hydroquinone and sodium metabisulfite. That gives you a long-lasting PQ developer, and there are several good PQ formulas around if you want to try that method. But in those formulas, I suggest replacing Phenidone with 1.3 times as much Dimezone S.

    Good luck,

    Mark

  10. #500
    Rafal Lukawiecki's Avatar
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    Thanks, Mark. Out of interest, do you prepare Dimezone S in propylene glycol so as to make it easier to measure such a small amount, or do you just use 0.001 precision scales, which would really mean 0.0001 precision, I suppose? I can see how making the concentrate can be a better proposition, overall, for the consistency of measurement.
    Rafal Lukawiecki
    See rafal.net | Read rafal.net/articles



 

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