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  1. #321

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    Quote Originally Posted by semi-ambivalent View Post
    Mark,
    As someone with an intimate knowledge of the miracle that is the drywall screw, and 400 feet of Eastman 5222 in the freezer, I intend to slavishly copy your film winder/counter in some fashion. Thanks! s-a
    I hope you find this idea useful. I guess if your bulk roll won't fit in a standard bulk-loader, then you'll need something like this. But if you do copy it, I suggest cutting out the top-middle section in a Vee-shape which I drew below:

    Click image for larger version. 

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    The purpose of this suggested cut is to prevent the wood from touching the film in the image-area, so it won't put scratches in your pictures.

    Mark Overton

  2. #322

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    D316 concentrate is behaving exceptionally well in tests. Here's how its density-curve compares with XTOL for TMY-2. D316 was 12 minutes; XTOL was 6.5 min:

    Click image for larger version. 

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    The match is outstanding, except that D316's shoulder is a hair better (i.e., higher). Here are full-resolution crops of scans:

    XTOL: Click image for larger version. 

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ID:	59933 D316: Click image for larger version. 

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    The scanner was manually focussed on the centre wedge. D316's grain is a hair finer than XTOL, which we've seen before with this type of developer, and JPEG file-size is 3% smaller, which objectively agrees that it's slightly less grainy. In loupes, grain looks the same to me. So does sharpness.

    So D316 is matching (or slightly exceeding) the image-quality of XTOL.

    I've also been making concentrates at various temperatures, and made the annoying discovery that propylene glycol evaporates as visible steam as low as 65C. When mixing, turn on the fume-hood over the stove, and don't worry about the constant steam.

    The concentrate can be mixed at 65C, but it takes over 45 minutes to dissolve everything. At 90C, you start risking crystallization after the ascorbic acid and Phenidone are added. The constant steam-loss of PG encourages us to keep hot-time to a minimum. I suggest the following procedure (multiply this 1-litre formula by at least 2):

    1. Heat 16 ml of propylene glycol to 85C.
    2. Add 2.2 g of sodium metaborate 4-mol. I saw a puff of steam.
    3. Stir until dissolved (a couple of minutes), keeping at 85C.
    4. Add 4.5 g of ascorbic acid. Temperature will drop to about 75C. Keep between 75C and 80C.
    5. When ascorbic acid is mostly dissolved, add 0.05 g of Phenidone.
    6. Still until all is dissolved (around 10 minutes at 75C-80C).

    I'm running more tests, but so far it's looking good.

    Mark Overton

  3. #323
    kb3lms's Avatar
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    Wait a minute?

    Mark,

    I lost track of this thread for a bit. You were writing about the "XTOL concentrate" before and are now testing "D316"? Are they one in the same?

    BTW, your inventions look pretty good! You can also get 35mm sprockets from disposable cameras.

    -- Jason
    All this has happened before, and all this will happen again.

  4. #324

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    Quote Originally Posted by kb3lms View Post
    Mark,
    I lost track of this thread for a bit. You were writing about the "XTOL concentrate" before and are now testing "D316"? Are they one in the same?
    BTW, your inventions look pretty good! You can also get 35mm sprockets from disposable cameras.
    -- Jason
    Jason, thanks for the note. I hadn't thought of disposable cameras. I got my sprocket from a 1950's Edixa rangefinder. Agfa Silettes and Argus C3 bricks also contain such solid-shaft sprockets. But disposable cameras are far more plentiful.
    D316 is one of the early concentrates I created back in January, and Alan Johnson mixed it and has been giving it a longevity-test. Out of all the work I've done since then, it's still the winner.

    Mark Overton

  5. #325
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    Gotcha, Mark on the D316. I have the formula for D316 now, just lost track of where the conversation had gone. Although I have all the raw materials to make up some D316, I stii haven't gotten it done and my last half-quart of XTOL still sits on the shelf slowly yellowing -it looks like you-know-what now - and I can't find the films I need to process.......

    But in the meantime you've done all this great work that we all benefit from. Your tests are very impressive. Thanks!


    P.S. and I defintiely agree with you about missing the party! I was a member here but didn't check in for a few years. IDK why, though.
    Last edited by kb3lms; 11-19-2012 at 08:21 AM. Click to view previous post history. Reason: Added info
    All this has happened before, and all this will happen again.

  6. #326

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    My tests are not as accurate as those done by Mark,but I found that APX100 gives a similar result in D316 to that obtained with Xtol.
    Whilst Ryuji cautioned that DS-10 was not satisfactory for some films including APX100,my initial test result is that D-316 is OK.
    http://web.archive.org/web/200906030...or_DS-10_users

  7. #327

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    I'm thinking of trying D316. I have two questions.

    1. If I use a bit more propylene glycol, say to make 25mL of concentrate instead of 20mL, will that make it easier to dissolve and less likely to crystallize, or will the different concentration of metaborate alter the solubility of the ascorbic acid? I would obviously use 25mL of the concentrate to make 1_L of working solution.

    2. Whichever version of sodium metaborate I have, it shouldn't make any difference, should it? In my post above where I pasted Ryuji's comments about the naming of sodium metaborate (tetrahydrate and octohydrate) although the theoretical compositions of the two compounds give very different molecular weights (one double the other) it seems to me that 2.2 grams of either is exactly the same when dissolved. I have bought chemicals from a supplier who has been generally a bit slack with noting water of crystallization, which usually makes a difference but not, I think, in this case. It's been a while since I did high school chemistry (1965).

  8. #328

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    Quote Originally Posted by john_s View Post
    I'm thinking of trying D316. I have two questions.

    1. If I use a bit more propylene glycol, say to make 25mL of concentrate instead of 20mL, will that make it easier to dissolve and less likely to crystallize, or will the different concentration of metaborate alter the solubility of the ascorbic acid? I would obviously use 25mL of the concentrate to make 1_L of working solution.
    Good to hear that!

    I think that boosting the propylene glycol (PG) will make it easier to dissolve the powders. But at the temperatures I gave, everything dissolved in a reasonable time, and comfortably below the crystallization-point. Boosting PG will have a small effect on the developer, as it reduces pH a tad. But I doubt the difference would be significant.

    Quote Originally Posted by john_s View Post
    2. Whichever version of sodium metaborate I have, it shouldn't make any difference, should it? In my post above where I pasted Ryuji's comments about the naming of sodium metaborate (tetrahydrate and octohydrate) although the theoretical compositions of the two compounds give very different molecular weights (one double the other) it seems to me that 2.2 grams of either is exactly the same when dissolved. I have bought chemicals from a supplier who has been generally a bit slack with noting water of crystallization, which usually makes a difference but not, I think, in this case. It's been a while since I did high school chemistry (1965).
    Actually, the kind of metaborate will make a substantial difference, because the number of moles of the anhydrous form (i.e., NaBO2) in 2.2 grams will differ. For 8-mol metaborate, you'll need 3.0 grams. If you have a pH meter, you can mix the ingredients directly into water (including the PG) and see if the pH is around 8.08.

    Without a pH meter, you could mix the concentrate using 2.2 grams, and see how long the ascorbic acid takes to dissolve at 75C (assuming 20 ml of PG). If it takes longer than 5 minutes to dissolve most of it, then you probably have the 8-mol s.metaborate, and will need to add another .8 grams of it. Alternatively, you could mix the concentrate using 20 ml of PG and 3.0 grams of metaborate, but at a temperature of 85C for everything. If it crystallizes (white marks on bottom of beaker and then cloudiness), then you know you should start over with 2.2 grams.

    Good luck,

    Mark Overton

  9. #329

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    Quote Originally Posted by albada View Post
    .......
    Actually, the kind of metaborate will make a substantial difference, because the number of moles of the anhydrous form (i.e., NaBO2) in 2.2 grams will differ. For 8-mol metaborate, you'll need 3.0 grams. If you have a pH meter, you can mix the ingredients directly into water (including the PG) and see if the pH is around 8.08.

    Without a pH meter, you could mix the concentrate using 2.2 grams, and see how long the ascorbic acid takes to dissolve at 75C (assuming 20 ml of PG). If it takes longer than 5 minutes to dissolve most of it, then you probably have the 8-mol s.metaborate, and will need to add another .8 grams of it. Alternatively, you could mix the concentrate using 20 ml of PG and 3.0 grams of metaborate, but at a temperature of 85C for everything. If it crystallizes (white marks on bottom of beaker and then cloudiness), then you know you should start over with 2.2 grams.

    Good luck,

    Mark Overton
    Thanks Mark. About metaborate:

    tetrahydrate NaBO2-4H2O
    octohydrate Na2B2O4-8H2O

    The octohydrate has twice the molecular weight of the tetrahydrate. So 2.2g of it would have half the number of moles. But each mole of it is equivalent to two moles of the tetrahydrate. When dissolved, wouldn't it be the same?

    (The situation seems quite different to something like, say, sodium carbonate, where the one mole of Na2CO3 can have zero, one, seven or ten molecules of water. Obviously then the water of crystallization has to be taken into account when weighing out.)

  10. #330
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    Quote Originally Posted by john_s View Post
    Thanks Mark. About metaborate:

    tetrahydrate NaBO2-4H2O
    octohydrate Na2B2O4-8H2O
    You might have misread something here. There are four compounds appearing in literature:
    1. NaBO2 * 2 H2O
    2. NaBO2 * 4 H2O
    3. Na2B2O4 * 4 H2O
    4. Na2B2O4 * 8 H2O

    Note that compounds 1 and 3 are effectively the same thing, and the same applies to compounds 2 and 4. Both compounds 2 and 3 could justifiably be called tetrahydrate but are certainly not the same, and that's where the confusion comes from. Mark has written about this and linked to relevant information. Make sure you know which compound you have and use the amount recommended by Mark for that amount. You dev is likely going to develop film even if you pick the wrong amount, but if you want to get the same good results that Mark achieved with his formula, you better get the metaborate amount right.
    Trying to be the best of whatever I am, even if what I am is no good.



 

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