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Photo Forum / Film Photography / Darkroom / November 2005Ingredients are hard to dissolved when making D76-D
i began from 52C distilled water and put in every ingredient exactlly in the order as instructed. but every ingredients seemed hard to be fully resolved before adding another one. i could not image how many time i should wait and the water temperature was going down. so i did not wait and put the completed solution on the fire and heat it to about 80C. now it seems okay. but i dont know whether i've did any harm to the solution and whether it is still usable. another question is, my Borax is decahydrate (Disodium Tetraborate, decahydrate), is it right?  Signaturesteven woody (id: narke) John McFarland: Hey, what are you guys doing? Alex: Get the f.ck out and don't come back! Some heavy sh.t's going down! - Elephant (2003) > i began from 52C distilled water and put in every ingredient exactlly in the > order as instructed. but every ingredients seemed hard to be fully resolved > before adding another one. i could not image how many time i should wait and > the water temperature was going down. It has been my experience that anything containing Metol is hard to dissolve unless the water is at least 100F. A suggestion I got from the Film Developing Cookbook was to dissolve a little bit of the sulfite in the plain water before trying to dissolve the Metol. I do that and it seems to help. I teach in a school darkroom and mix my Dektol in 5 gallon batches (packaged) and throw in about a tablespoon of sulfite in the water before starting adding the mixed powder. It does help the Metol in the Dektol dissolve. A tablespoon of sulfite in 5 gallons doesn't seem to make much different with the end results. I a school darkroom, there are so many other things which can affect the final results than a wee bit more sulfite. > so i did not wait and put the completed solution on the fire and heat it to > about 80C. now it seems okay. but i dont know whether i've did any harm to the > solution and whether it is still usable. > > another question is, my Borax is decahydrate (Disodium Tetraborate, > decahydrate), is it right? > > i began from 52C distilled water and put in every ingredient exactlly in the > > order as instructed. but every ingredients seemed hard to be fully resolved [quoted text clipped - 21 lines] > > another question is, my Borax is decahydrate (Disodium Tetraborate, > > decahydrate), is it right? thanks for your infor. i am thinking if post-heating is not harmful, why not people use this simple method ? I thought the sulfite was to prevent the metol from combining with the oxygen in the water which produces a permanent bond that is useless as a developer. That's why the sulfite is called a preservative. I didn't know that it had any effect on solubility. -Lew > I thought the sulfite was to prevent the metol from combining with the > oxygen in the water which produces a permanent bond that is useless as a > developer. That's why the sulfite is called a preservative. I didn't know > that it had any effect on solubility. I admit I'm not a chemist. I don't even play one on TV. Perhaps one more scientifically inclined could explain why sulfite help metopl to dissolve. I just know tht it works. > -Lew could you experts tell me whether my solution keep still usable after did the post-heating things as i described. thanks! > > I thought the sulfite was to prevent the metol from combining with the > > oxygen in the water which produces a permanent bond that is useless as a [quoted text clipped - 5 lines] > dissolve. I just know tht it works. > > -Lew >I thought the sulfite was to prevent the metol from >combining with the oxygen in the water which produces a >permanent bond that is useless as a developer. That's why >the sulfite is called a preservative. I didn't know that it >had any effect on solubility. > -Lew It doesn't. Metol is very hard to dissolve in concentrated solutons of Sulfite which is why it is always the first ingredient in formulas containing it. The old advice about adding about 15 grams per liter of sulfite is to scavenge the oxygen out of the water. In fact its probably not necessary because there is usually an excess of Metol in formulas containing it. One way to minimize oxidation is to boil the water you are going to use. Bring to a heavy boil for about 5 minutes and allow to cool while standing. This will drive off dissolved gasses, remove some mineral matter (which gets deposited on the vessel), and cook any organic matter in the water so it pecipitates while cooling. When cool decant the clear water (or use a syphon) in a way that will not beat air back into it. Its sometimes helpful to make up developers in separate solutions. For D-76, for instance, make up the Metol in a portion of the water and then add it to the sulfite solution. This method was recommended in a very early edition of a photographic chemistry book published by Kodak (late 1920's), it does not appear in later editions. Kodak recommends a temperature of 125F (52C) in the formula for D-76. Higher temperatures can decompose the sulfite and should not be necessary. It does no harm to keep the solution temperature up while its dissolving. Current packaged D-76 recommends a lower temperature but probably has something in it to help things go into solution. I also don't know what Kodak does to allow dissolving the ingredients of Metol containing developers like D-76 and Dektol from a single powder. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com > >I thought the sulfite was to prevent the metol from > >combining with the oxygen in the water which produces a [quoted text clipped - 27 lines] > sulfite and should not be necessary. It does no harm to keep > the solution temperature up while its dissolving. Richard, what are the effects of higher temperature? you said that will not be necessary. but any harm does it do? becase the ingredients are not fully dissolved, i was keep heating the completed solution on a fire until it was fully dissovled. is there any harm of my procedure? i am highly interested if i need to re-make another solution. thanks. > Current packaged D-76 recommends a lower temperature but > probably has something in it to help things go into [quoted text clipped - 7 lines] > Los Angeles, CA, USA > dickburk@ix.netcom.com > becase the ingredients are not fully dissolved, i was keep heating the > completed solution on a fire until it was fully dissovled. is there > any harm of my procedure? i am highly interested if i need to re-make > another solution. It is interesting that you need a rather high temperature to dissolve D-76. I usually take about 250ml demineralized water, put it into the microwave until it boils and add this to 700ml cold demin. water. This gives about 40 deg. C, and I just throw the whole D-76 ingredients into the water and stir it for about 10min on a magnetic stirrer. I use D76H and just put all three parts (2.5g Metol, 2g Borax and 100g Sodiumsulfite) in a airtight jar when weighting new developer. I never had any problems to dissolve any part, and I found that Metol dissolves in a 10% solution of Sodiumsulfite without any problems. It probably helps that I use a magnetic stirrer and let it run for about 10min (without heating) before using it. With this method, I have no undissolved crystals in the solution. Martin > > becase the ingredients are not fully dissolved, i was keep heating the > > completed solution on a fire until it was fully dissovled. is there [quoted text clipped - 16 lines] > > Martin thanks. but God! why nobody likes to answer my most important question? can i use the post-heated solution! i sit here waiting for an answer, then i have to decide if or not throw it . please, please help me .... actually, if my method is okay, i won't going to bother why ingredients can not dissolve easily. i just need to put all ingredients and put the solution on a fire untill every crystal disapear. if you guy think my method is invalid, and i've make a unusable solution. so i won't use it to develop my films and going to study how to dissolve ingredients in a proper mannar. - narke > thanks. but God! why nobody likes to answer my most important > question? can i use the post-heated solution! i sit here waiting for > an answer, then i have to decide if or not throw it . please, please > help me .... I dont know but you can always do a quick test ? Koen > thanks. but God! why nobody likes to answer my most important > question? can i use the post-heated solution! i sit here waiting for > an answer, then i have to decide if or not throw it . please, please > help me .... > actually, if my method is okay, i won't going to bother why ingredients > can not dissolve easily. i just need to put all ingredients and put > the solution on a fire untill every crystal disapear. Well, I read several times that you shouldn't heat D76 and similar developers to more than about 50 deg. C. I'm not sure which part of the solution isn't stable at higher temperatures (probably the Metol), and maybe this is one of the famous UL that get repeated from generation to generation. Anyway, I would develop a test strip and than I'd know ;-) Martin Quit whining, sorry it's just bad form to "DEMAND AN ANSWER RIGHT NOW, DANG IT" on newsgroups. Sometimes the answer is "I don't know (because I've never tried it)." Usually though rather than display "our" ignorance NO ANSWER = I DON'T KNOW, keep in mind, everyone here has a real job and works at other things, very few of us are professional newsgroup gurus (great job, lousy pay and benefits) so we don't have time to try every little thing under the sun and will not always have an immediate answer for something that went wrong (or horribly wrong). I did have a similar problem with some store bought Dektol a while back, crud (technical term for insolubles) in the bottom of the mixing graduate after stirring forever on my stirplate (would have given up MUCH sooner if I had had to stir the mix by hand!) then called Kodak and they replaced it. Filtered, the original solution worked just fine, but you get unlimited "do-overs" with print developer. For film, I'd filter out the crud, (coffee filter in a funnel will get the job done) and test on some non-critical film. Used to be D-76 recommended 125 F. that's Signaturedarkroommike ---------- <snip> > > thanks. but God! why nobody likes to answer my most important [quoted text clipped - 12 lines] > - > narke Sorry didn't finish the last line (windows 98 locked up) 125 F is 51.666666666666 Celsius (pretty close to 52). The 100 F. may be a more recent recommendation. Signaturedarkroommike ---------- > Quit whining, sorry it's just bad form to "DEMAND AN ANSWER RIGHT NOW, DANG > IT" on newsgroups. [quoted text clipped - 31 lines] > > - > > narke > Sorry didn't finish the last line (windows 98 locked up) Don't have a copy of NT around anywhere ? I'm back to Windows 2000 Pro after installing a ATI video driver. I should have known better. There are a few good reasons Nvidia is #1 and ATI's drivers are at the top of the list. SignatureRegards, John S. Douglas, Photographer & Webmaster http://www.puresilver.org - http://www.legacy-photo.com > Quit whining, sorry it's just bad form to "DEMAND AN ANSWER RIGHT NOW, > DANG IT" on newsgroups. Yeah but instant gratification and the internet have a lot in common. The average person. SignatureRegards, John S. Douglas, Photographer & Webmaster http://www.puresilver.org - http://www.legacy-photo.com > Quit whining, sorry it's just bad form to "DEMAND AN ANSWER RIGHT NOW, DANG > IT" on newsgroups. [quoted text clipped - 13 lines] > crud, (coffee filter in a funnel will get the job done) and test on some > non-critical film. i was just too impatient, i am sorry for that :( > Used to be D-76 recommended 125 F. that's No problemo, we all have questions like that from time to time, BTW how is your situation working out, did you remix or try is anyway? Signaturedarkroommike ---------- > > > Quit whining, sorry it's just bad form to "DEMAND AN ANSWER RIGHT NOW, DANG [quoted text clipped - 18 lines] > > > Used to be D-76 recommended 125 F. that's You may have some bad powders. I once had the same problem, and it turned out my hydroquinone was too old and had deteriorated. > > > becase the ingredients are not fully dissolved, i was keep heating the > > > completed solution on a fire until it was fully dissovled. is there [quoted text clipped - 32 lines] > - > narke No need for the borax in that low metol D23 some call D76H. That 2 grams of borax came with the origanal D76 and it's hydroquinone for buffering purposes. Dan Specifically, I don't think you damaged your developer. The only hazard is decomposing the sulfite if the temperature is too high. It has to be very hot to do that. Plus you would smell it (sulfur odor). The developer should be clear. When aged D-76 can be a very slight straw color but when fresh should be clear and not yellow or brown. Of course, the real test is to try developing with it. Use the same sort of clip test you would if testing film. Even just a clip of fogged film will do. Develop it for a normal time and fix it. Check the density. It should be very dense. If its light gray or it did not develop dump the developer. My bet is that its just fine. Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com |
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