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  1. #201

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    Jerry - what do you fuse the borax in? And then how do your get it out??

    I'm guessing that you'll need a ceramic crucible. And from making borax beads in Qualitative Chemistry class, then when the fused borax cools, it's going to make a rather hard block in the bottom of the crucible. And hard to get out without breaking the crucible...

    I used to analyze plant matter for fluoride (they were testing down-wind from an aluminum refining plant) by dissolving it in sodium hydroxide using zirconium crucibles. (You could not use ceramic as the glazing on the ceramic dissolved, and you could not use a platinum crucible as the platinum would dissolve - a rather expensive mistake if one tried it!!) The hydroxide would set up so hard in the crucible that you could not chip it out without it flying all over the place, causing you to ruin the sample, so I came up with the trick of swirling the hot, molten hydroxide around until it chilled and set to the sides of the crucible. Then when fully cool, I could toss them in a beaker and rinse them with dilute HCl until the hydroxide dissolved. You can't do that when you're trying to make anhydrous borax...
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  2. #202

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    Quote Originally Posted by Kirk Keyes View Post
    Great find on the pH meter! That should give much better results than your old one. Keep looking for a temp probe. It may be cheaper to get a second electrode with a built in temp sensor than buying the sensor outright.
    Yes, that thing is going to spoil me. But I figured out a trick for getting a temperature into the meter: apply a resistance to the ATC connector using a potentiometer. That way one can simply dial-in the temp seen on the thermometer. This evening, I tried various resistors and got a table of corresponding temperatures from the meter, so now I know what kind of resistor-network to solder together. That's another electronic hack until I find a temp probe (and I like your idea of an electrode with built-in temp sensor).

    I also brewed another concentrate this evening. Tests done by Alan Johnson and myself show that a concentration-ratio of 0.34 is stable. A recent concentrate at 0.46 is crystallizing a little. So I just mixed one halfway between them, at 0.40. Here's hoping...

    Mark Overton

  3. #203
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    Quote Originally Posted by Kirk Keyes View Post
    by dissolving it in sodium hydroxide using zirconium crucibles.
    [...]
    so I came up with the trick of swirling the hot, molten hydroxide around until it chilled and set to the sides of the crucible. Then when fully cool, I could toss them in a beaker and rinse them with dilute HCl until the hydroxide dissolved.
    I was not aware of the difficulties in dissolving NaOH ... or did I miss something ?
    Trying to be the best of whatever I am, even if what I am is no good.

  4. #204
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    Kork said noting about NaOH being difficult to dissolve. He was describing a lab technique that allowed one to prevent formation of big chunks of NaOH. Instead, by swirling, he formed a thin film of NaOH.

    PE

  5. #205

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    Quote Originally Posted by Kirk Keyes View Post
    Jerry - what do you fuse the borax in? And then how do your get it out??
    I would not allow the borax to cool in the crucible but rather pour it out immediately after the fusion. I would use the unglazed side of a tile. The solid will have to be ground up in a mortar. However as I said before it's easier just to buy the stuff. Years ago on a weekend when everything was closed I had to make some anhydrous sodium metaborate by fusing borax and sodium hydroxide.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

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  6. #206

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    Quote Originally Posted by albada View Post

    After more experimenting, I've come up with the formula below. Its grain is slightly better than XTOL, sharpness is the same, and dev-times are longer. The 1-litre formula for mixing directly into water:

    Sodium sulfite ................. 45 g
    Sodium metaborate ........ 2 g
    Ascorbic acid .................. 4.5 g
    Phenidone ...................... 0.05 g
    Target pH = 8.05 to 8.10.
    13:40 minutes for TMY2.

    For a concentrate, mix everything except sulfite into 16 ml of propylene glycol.

    Mark Overton
    A plastic Tablespoon was dipped into sodium sulfite,wiped off level with a card.Consecutive weights (grams) were:
    25.3,23.5,23.5,23.7,23.3,24.5,24.3,24.3,23.6,24.0; Average=24.0g
    I daresay 2 level plastic Tablespoons of sodium sulfite would be OK for this formula.
    I am in favor of spoons because I remember Crawley's FX-55 developer, great developer, nobody AFAIK uses it because it calls for ingredients to be weighed out each time to make the working solution.
    As there is no international spoon users would need to calibrate their spoon first.
    And remember to use the multiplying factor if use 8-mol sodium metaborate,the formula above is for 4-mol.

  7. #207
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    Alan;

    Back to the old argument. Well, tablespoons vary a bit in the US, and chemicals vary in crystal habit from batch to batch and even in one batch. I have found a variation of greater than 20% just due to crystal habit. This is often not accurate enough. It depends on the effect of the chemical in question.

    PE

  8. #208

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    Alan's posting made me think again about how to measure. Teaspoons and tablespoons make it easy.
    What do folks think of this idea?:

    The problem is: To make some one-shot developer, you need to measure some sulfite powder and concentrate liquid.
    My idea is to use plastic medicine cups, like these:
    http://www.amazon.com/%60Medicine-Cu...+medicine+cups
    That low price is for a package of 100, so the individual cups cost almost nothing.

    Step 0: Before measuring anything, you draw two horizontal lines at the correct fill-levels on a cup using a black felt-tip marker. You only need to do this once, and the black lines make it easy to see the fill-levels.

    Step 1: Measure the sulfite powder, tapping the side of the cup to flatten the surface of the powder (and to compact it).
    Step 2: Pour into the empty beaker.
    Step 3: Measure the concentrate liquid.
    Step 4: Place the medicine cup in the beaker (on the powder).
    Step 5: Add the correct amount of water to the beaker.
    Step 6: Stir until the powder is dissolved, and remove the cup from the beaker.

    The advantage of this approach is it can handle any quantities, such as 225 ml for 35mm SS tanks, or 550 ml for 120-film in Paterson, or anything else. But are the above steps too much of a hassle?

    Mark Overton


    Quote Originally Posted by Alan Johnson View Post
    A plastic Tablespoon was dipped into sodium sulfite,wiped off level with a card.Consecutive weights (grams) were:
    25.3,23.5,23.5,23.7,23.3,24.5,24.3,24.3,23.6,24.0; Average=24.0g
    I daresay 2 level plastic Tablespoons of sodium sulfite would be OK for this formula.
    I am in favor of spoons because I remember Crawley's FX-55 developer, great developer, nobody AFAIK uses it because it calls for ingredients to be weighed out each time to make the working solution.
    As there is no international spoon users would need to calibrate their spoon first.
    And remember to use the multiplying factor if use 8-mol sodium metaborate,the formula above is for 4-mol.

  9. #209
    Cor
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    Just today I came across above thread, I do not stop by APUG that often. Cannot pretend to have it read completely nor understand everything, but it is truly a heroic and determined effort Mark !

    I am test driving InstantMytol now for about 6 months, and have been very satisfied with it, so I wonder why you did not give that formula a try (or perhaps you did).

    Just FYI I'll post my procedure below, but really Jordan Wosnick should be credited for this developer !

    Best,

    Cor

    InstantMYTOL

    Stock solution in propylene glycol / triethanolamine:
    Start with 13.4 ml hot triethanolamine (hotplate at 100degC)
    25 ml hot propylene glycol
    11.5 g ascorbic acid
    0.15 g phenidone

    Stir until all solids have dissolved (it will take quite a while, and may require the addition of 1-2 ml of water). Dilute with hot propylene glycol to a final volume of 50 ml.

    Solution turns brown after about 6 months!

    Make 15% Sodiumsulphite (anhyd.) solution and distribute to smaller bottles with either 60 ml (35mm) or 100 ml 15% sulfite solution. Fill completely with MQ ( that is destilled water, actually Millipore filtered) to avoid oxidation.

    For 35 mm film, equal to Xtol 1:1 (end volume 300ml):

    7.5 ml InstantMytol + (15 gr sulfiet);
    Small 100 ml bottle with 60 ml 15 % sulfiet, fill with MQ.
    (to prevent oxidation to sulphate)

    For 120 film, equal to Xtol 1:1 (end volume 500ml):

    12.5 ml InstantMytol + (9 gr sulfiet);
    Small 100 ml bottle with 100 ml 15 % sulfiet, fill with MQ.

    (btw dispensing the viscuos liquid is not easy, I use a very small 10 and 20 ml graduates for that, and even than it take effort and thorough rinsing of teh graduate)

  10. #210

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    Quote Originally Posted by Cor View Post
    I am test driving InstantMytol now for about 6 months, and have been very satisfied with it, so I wonder why you did not give that formula a try (or perhaps you did).
    Welcome back, Cor!

    Yes, I tried Instant Mytol a while ago. But I noticed some problems with it:

    * Using TEA from Photographer's Formulary (85% pure), the pH was too high. In fact, I mixed Instant Mytol three times, but the high pH produced negatives that were too dense and grainy. Using a 99%-pure TEA available elsewhere might have helped. But the problem remains: TEA is different depending on where people buy it.

    * It oxidizes quickly. Here's what mine looked like after two months:
    Click image for larger version. 

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    * It uses 50 ml of concentrate per litre (1+19 dilution). I wanted higher concentration.

    * As you point out, its viscosity is high (it's thick), making it hard to pour and measure.

    While experimenting with concentrates, I made two discoveries:

    1. Sodium metaborate dissolves in propylene glycol. Normally, inorganic salts don't dissolve in organic solvents, but sodium metaborate is an exception.

    2. Ascorbic acid is easier to dissolve in propylene glycol if you have dissolved some sodium metaborate in it first. The metaborate helps the ascorbic acid to dissolve faster.

    So I've been researching concentrates that take advantage of these two discoveries. The concentrate that Alan quoted above is my best so far that uses Phenidone. It only uses propylene glycol as the solvent, so it's easy to pour and will not suffer the inconsistency of TEA. It is diluted 1+49 (use only 20 ml per litre), and my tests so far show that it matches XTOL. This type of formula looks promising, which I call SMAP -- Sulfite/Metaborate/Ascorbic/Phenidone.

    Mark Overton



 

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