Metol in glycol now horrible brown

Discussion in 'B&W: Film, Paper, Chemistry' started by Murray Kelly, Jun 23, 2009.

  1. Murray Kelly

    Murray Kelly Member

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    I thought to make up a concentrate of metol in ethylene glycol (propylene not available here, Australia) so followed the instructions from another thread with a slurry of glycol and metol with the TEA and small amt. of water all stirred together, with some small heat applied. Finally made up to volume with more e-glycol.
    Looked good for a week (pretty green - antifreeze) but gradually it's gone to coffee color over the month since I brewed it. I'd say it was dead.
    Anyone else had such an experience?
    I want to try various metol developers without going down the path of making larger quantities that will probably be never used again - a concentrate offers the freedom to try this and that without that drawback.
    Is ethylene (v. propylene) glycol unsuitable for a metol concentrate?
    Murray
     
  2. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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    What turns the metol brown is oxygen - assuming all the ingredients were good, then putting the glycol and TEA in a 300F oven for an hour and boiling the water for 10 minutes should drive off any dissolved gasses. Mix the metol into the cooled degassed liquid. You still need to keep the stuff in an air-tight/air-free container and away from bright light. Adding some sulfite after the metol has dissolved will help to preserve the metol. As metol is never used without sulfite (TTBOMK) the sulfite addition will not limit your use of the metol.

    I am not sure of the reason for doing this, metol keeps very well as a powder. If you want a liquid form you might just want to make up D-23 developer as a 'soup base', as it were: Add more sulfite, HQ & borax/boric acid to make D-76; add carbonate, HQ and bromide to make D-76; add pickling salt to make Microdol-X ... D-23 keeps for several years in well stoppered bottles if made with degassed distilled water.
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    Murray;

    The extra components of EG in antifreeze can be the cause of part of the problem, as can be the addition of the water. The idea of many of these concentrates is to totally eliminate water. If water is present, you need some sulfite.

    PG is safer. EG is quite toxic. PG is widely used in the dairy industry and food industry.

    PE
     
  4. Murray Kelly

    Murray Kelly Member

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    I know that oxygen is the culprit.
    I was lead to believe that the concentrate was immune from this problem if prepared this way. The amount of water is minimal. Seems it is still too much.
    I'm not sure, but there is IIRC benzoate in there, too. As a denaturant? Will have to check the label again, tomorrow. Now 1am.
    I am aware of the oral toxicity of e-glycol. I promise not to drink it.
    The container is glass with a metal lid and a rubber sealing ring. Kept in the dark and cold.
    Wasn't thinking D-23, more your pyrocat etc or the Pyrocat-MC. No Sulfite.
    Didn't think of boiling the water. If there's no water, theoretically it shouldn't go 'off', but how to dissolve the metol without it?.
    Thanks. Off to bed.
    Murray
     
  5. Alan Johnson

    Alan Johnson Subscriber

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    Well, Mr Gainer is the expert on this but my guess is that only enough water is needed to remove the sulfate from the metol:
    (C7H10NO)2.S04 +H2O -> H2SO4 + etc.
    For 344.38g metol 18g water would react thus.
    Don't take this as reliable, I never saw an expert give details of the reaction.
     
  6. Photo Engineer

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    TEA will react with the sulfuric acid and TEA.Sulfate should dissolve in the EG. The Metol free base should then dissolve, but IDK. Not sure about the formula.

    PE
     
  7. srs5694

    srs5694 Member

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    The usual reason for doing this with phenidone is to simplify measuring relatively small quantities of phenidone for developing just one or two rolls of film. A typical metol formula uses about ten times as much metol as a phenidone formula does of phenidone, so there's very little benefit to mixing up a solution of metol in glycol. For instance, a liter of full-strength D-76 uses 2.0g of metol, vs. 0.2g of phenidone in a liter of full-strength E-76. If you've got a scale that can measure with a precision of 0.1g, you'll get reasonably good consistency in your measurements of 2g of metol. Scales with a precision of 0.01g are fairly inexpensive (although the cheapest of these may not be very durable), so even if you wanted to mix up 250ml of 1/2-strength D-76, thus requiring 0.25g of metol, you could do it with pretty good repeatability of your metol measurement. This is the way I'd go, rather than mix metol in a glycol -- and particularly in automotive anti-freeze, which as PE says, contains other ingredients that might be detrimental to the keeping properties or to developers generally.
     
  8. gainer

    gainer Subscriber

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    I don't remember why I proposed this, but it is used in the preparation of Pyrocat MC. I have several bottles of that dark brown sludge. Just for fun, try making a dose of D-23 to see if it really is dead. Many chemicals of its ilk are, IIRC, pretty strong dyes. I'll do the same here. You could also try Metol and ascorbic acid in 800 ml saturated borax solution brought up to 1 liter with plain water.
     
  9. gainer

    gainer Subscriber

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    My little brown bottle did nothing but be brown. How enough oxygen could be trapped in that bottle to kill several grams of metol base, I do not know. Perhaps there is some other mechanism for self destruction. According to Sandy King, the Pyrocat MC has a good lifetime. It does have the ascorbic acid for preservative.
     
  10. Murray Kelly

    Murray Kelly Member

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    My thanks to all. Back to the drawing board?
    The reason I want to experiment with small quantities BTW is that I only need 100ml of developer to do a strip of 16mm microfilm from the Minoltas.
    I am looking for pictorial and phenidone has 'problems' such as uneven tonal gradation in seemingly even gray areas. It has to be dilute (not Beutler) and low pH.
    Murray
     
  11. john_s

    john_s Subscriber

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    Murray, you can get propylene glycol at Actrol (11 branches in Queensland). It's used in refrigeration equipment.
     
  12. Murray Kelly

    Murray Kelly Member

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    Back from the once a month 'lunch' - Clare Valley offerings :smile:
    John - so far my best and most polite response has been 'bugger off, mate'. Maybe Queenslanders aren't so polished as Victorians? No!!!. yes. :sad:
    I will ponder the problem. I did read on Wiki about dehydrating solutions with anhydrous CuSO4, easily made from bluestone (or MgSO4 (sec) - slower but perhaps better). Therefore, after the conversion from the salt, remove all water. The oxygen only works on the metol in an aqueous environment.

    Murray
     
  13. eclarke

    eclarke Member

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    My MC is two years old, stored in little brown bottles, is dark brown and works just fine...Evan Clarke
     
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  15. john_s

    john_s Subscriber

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    That's weird. At my local one, they had 4 or 5 Litre cans on the shelf for retail sale. I will phone them and see if they still sell it in such quantities.
     
  16. Photo Engineer

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    Murray;

    I would not use the Copper salt, and the Mg salt may be a bad idea too.

    PE
     
  17. gainer

    gainer Subscriber

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    You could try the PFS-3 that I posted elsewhere: 800 ml saturated borax solution, 6 grams ascorbic acid, 15 ml 1% phenidone in glycol, water to 1 liter. It will be self-replenishing for up to 10 rolls, so use it like D-76 and pour it back in the bottle. To make the borax solution, put a pound or more of borax in a 2 liter soft drink bottle, fill it with water at your normal developing temperature, stir it well and decant the amount of clear solution you need. Add water to the borax solution as you use the clear liquid. A pound should make almost 10 liters of saturated solution before it is all dissolved. More than 10 if it happens to be partly pentahydrated borax.
     
  18. Photo Engineer

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    I ask this question politely again:

    Is there any proof of the image structure yielded by this developer formulation? Any sharpness, grain or speed comparisons? If not, then it is just a developer, and may be no better than using Dektol for your film.

    Sorry Patrick, but the question must be asked and asked politely and with respect. But to date, I have seen no proof that this and your other developers are anything but developers, some with long shelf lives.

    PE
     
  19. Kirk Keyes

    Kirk Keyes Member

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    Also keep in mind that the amount of borax in your saturated solution changes greatly with temperature. A saturated solution at 50F will have about 33% less borax in it than one at 68F, and one at 86F will have about 53% more borax in it. You may get 13 liters in the winter, but only 6 in the summer...

    If you can control the temp of your solutions so the you don't have to worry about it, then that's great. My darkroom changes nearly throughout the entire range I mentioned above (55F in the winter to about the low 80s in the hottest part of the summer), so I find it's just so much simpler and much more accurate to measure my borax out on my scale.
     
  20. Kirk Keyes

    Kirk Keyes Member

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    A long time ago, back when I was a teenager in Oregon and before I became a scientist, I used Dektol to develop my film. I used a Kodak Tri-Chem Pack. Dektol for the film developer, and Dektol for the paper developer. It worked! Sure, it was a bit grainy, put it worked!
     
  21. Murray Kelly

    Murray Kelly Member

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    PE, to answer your question only in part, the Phenidone-C-Borax Does work nicely with microfilm but I want to try it with metol in the hope of getting even better gradation of grays. However, that film has no discernible grain so I can't help there but it can always use any help with sharpness. I suspect metol would be an improvement, but at an even lower pH. I have tried Technidol and it goes brown, not pink (?metol?) and has a pH about 8.8 a bit lower than borax. I thought the P-C-Borax looked better. To my eye anyway.
    So far it's all just suspicion. I would like to try some variation on Pat's brew and it will need experimentation, hence my 'need' for the stock metol.
    The P-C-Borax was most encouraging with Copex Rapid but had the disadvantage mentioned above with areas of constant gray - there is a problem with bands forming in places there should be none.
    So, yes, for me it's a way to experiment. I just differ from Patrick by using it stand or semi-stand. That's something I could try with Technidol and diverge hugely from the Kodak engineers' recommendations.

    John-S - I think you are right and I will chase it up - it costs almost $100/4 L. Someone else has 25L for $200 but even if I live to be as old as my father I couldn't justify it for the next 20 years! Maybe some Oz folk might like to help part it out?

    Anyway - my question is mostly answered. It does go 'off' and I will look to another solvent. I am studying MSDS and find there's all kinds of additives in antifreeze if one isn't careful. Some have almost none and others have stuff like disodium phosphate which can't help, and one has borax. I will trawl the auto suppliers and garages and take notes.
    Good night all. 3am.
    Murray
     
  22. gainer

    gainer Subscriber

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    Don't be sorry. My only demonstration so far was in the Borax article. It is very difficult to show sharpness and grain by digital transmissions, especially when there are limitations on the size packet one can send. I can, and have on occasion, digitized a small part of a darkroom print. Anyway, there is no financial motive for me to "sell" any formula I propose. I only propose one to demonstrate some experiment or to help someone I think may be helped by it.

    If I were trying to sell a bill of goods, the buyer would certainly be entitled to a valid demonstration of its value. If you want only to show that Gadget Gainer is just a nut with nothing to give, then mix up a batch and test it. It's cheap and easilly made. I did not claim it to be good for stand development, so if it fails there, don't hold it against me. I have not tried it as a stand developer myself, and do not plan to.

    So, don't be sorry, but do test it for yourself as you would any commercial developer before telling others it cannot be any good.

    I will say that the grain from Arista 400 Supreme in a super B digital print made from a scan of a darkroom 8x10 print is not visible at 12" viewing distance. Resolution is as good as the 50 mm Canon 1.8 lens provides. I used 0.5 f-stop exposure bracketting with my test rolls and could see very little difference in exposure scale from one shot to the next when each frame was of normal contrast.

    I'm going to try to illustrate some of this by a photograph in my next post.
     
  23. gainer

    gainer Subscriber

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    Sharpness, grain, gradation of SPF-3 PCB

    These have had no digital modification except cropping.
     

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  24. john_s

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    Actrol in Moorabbin (Vic) today quoted $52 for a 5Litre tin. Three in stock. Actrol in Queensland should be able to do the same, one would think!

    25L would take a while to use, like my 25kg of potassium carbonate!
     
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  25. Murray Kelly

    Murray Kelly Member

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    That sounds better. Do you supply your own container? I haven't rung up yet - tomorrow is Friday so will probably give them a go then.
    Don't want to part out a kilo of K2CO3? :smile:

    Patrick, that looks pretty good to my eye for a 400 ISO film. What's with the SPF-3 PCB label?:confused: Let me guess - it's the 3rd iteration? Or, the SPF-3 is the solvent?
    Looking at the MSDS of brake fluid leads me to think it might be a better substitute than anti-freeze because there is less by way of additives that will clash with our chemistry. I have some phenidone in BF and it's keeping fine.

    Oh Ron - thanks for the HU on the CuSO4/MgSO4 dehydration - it was just something that came up in Wiki with pictures to help, even, on dehydrating organics and I could see that there was some merit in the idea. Seems to me any water is ultimately going to give a headache with the metol. Pat's AA might protect it.
    I 'resurected' some quite brown metol with a hefty dose of ascorbic acid - returning it to a clear solution. Unscientific? Yes. Interesting, tho.

    Murray
     
  26. eclarke

    eclarke Member

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    "I 'resurected' some quite brown metol with a hefty dose of ascorbic acid - returning it to a clear solution. Unscientific? Yes. Interesting, tho."
    Yes, interesting..how much in how much in what exact solution?..Evan Clarke