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Photo Forum / Film Photography / Darkroom / April 2004Rodinal
Hi all, Rodinal is not available in Turkey. I believe it is because in part Agfa's low profile marketing strategy. Anyway, I read a lot about Rodinal and decided to try it. I bought some rodinal in the U.S and am ready to give it a shot. It is half a liter bottle of Rodinal. I was hoping that it has a long shelf life like the T-Max developer I mainly use and bought the larger bottle. T-Max developer has a shelf life of 2 years in proper conditions. As I do not develop not more than 1-2 rolls of film in a week, shelf life is important to me. In the leaflet of rodinal, it says once the original bottle has been opened, the stock will keep for 6 months. I know Rodinal is very concentrated like the T-Max and I am wondering if keeping the stock rodinal in air tight brown glass bottles (trying not to leave any air in the bottles by moving the stock in smaller bottles as it is consumed) will help extend the life of stock rodinal over 6 months. I have another question. I use 300 ml of working solution to develop 35 mm. films. the 1+50 dilution requires really little amounts of stock developer. Is there a threshold for the stock amount to be used, any minumum limits? Thank you all for helping me. Kind regards, Alparslan Rodinal is a very long lasting dev - years. In the past, when I used it (it's not available in Brazil, also - same Agfa problem as in Turkey) I used an hypodermic syringe and a thick needle through the (then, don't know nowadays) rubber cap to take 5cc out of it and solve in 250cc of water. Jorge > Hi all, > [quoted text clipped - 22 lines] > > Alparslan Jorge -- whatever happened to the CCS for the LEDs? Jack > Rodinal is a very long lasting dev - years. > [quoted text clipped - 31 lines] > > > > Alparslan John It's going, albeit slowly. I already have all the LEDs, the optical front silvered mirrors for the lightbox are cut to size, monday I will have the LEDs mounting plate ready. Then I can start the first preliminary tests (light eveness, etc) before assembling the light source in the enlarger head in place of the lamp. Jorge > Jorge -- whatever happened to the CCS for the LEDs? > > Jack > Rodinal is a very long lasting dev - years. > [quoted text clipped - 4 lines] > > Jorge Hi, then, are suggesting 10 ml. is not the minimum limit per roll of 35 mm. film no matter how much solution there is? Just trying to clarify. I am bit confused as there are different claims about the minimum amount. Meanwhile I will use 10 ml. minimum to be on the safe side. Regards. >> Rodinal is a very long lasting dev - years. >> [quoted text clipped - 10 lines] >confused as there are different claims about the minimum amount. Meanwhile I >will use 10 ml. minimum to be on the safe side. Regards. Rodinal is often used in very low concentrations. This tactic is useful in limiting highlight density and contrast in certain films, also useful in stand developing to increase edge effects for acutance. For instance at 1:200 for 120 film I would use about 2 1/4 cc to 15 oz water, agitate for 1 minute then let stand for the next hour with no agitation. Contrast is controlled by changing the concentration by careful degrees until the best results are obtained. Rodinal seems to have an unlimited capacity to develop even at very low concentration, though I'm sure there is a practical limit somewhere. > Hi, > then, are suggesting 10 ml. is not the minimum limit per roll of 35 mm. film > no matter how much solution there is? Just trying to clarify. I am bit > confused as there are different claims about the minimum amount. Meanwhile I > will use 10 ml. minimum to be on the safe side. Regards. 10ml per roll is overkill. The 10ml recommendation Agfa gives seems to be mostly based on them wanting to sell Rodinal. You can safely use 5ml. I get consistent results with 4ml Rodinal + 300ml water (1+75). Cheers, Tobias I've NEVER used the 10cc minimum! And I have a relative that was a pro photographer (nowadays he's a pro videomaker) that used only Rodinal and never said anything regarding the 10cc minimum. Agfa wants to sell more Rodinal... Jorge >> Rodinal is a very long lasting dev - years. >> [quoted text clipped - 11 lines] > amount. Meanwhile I will use 10 ml. minimum to be on the safe side. > Regards. > Hi, > then, are suggesting 10 ml. is not the minimum limit per roll of 35 > mm. film no matter how much solution there is? Just trying to clarify. > I am bit confused as there are different claims about the minimum > amount. Meanwhile I will use 10 ml. minimum to be on the safe > side. Regards. I don't care how long a 500ml bottle of Rodinal will last. If I had that much and used it that little I'd put it into 4, 125ml brown Boston Rounds equipped with Polycone or Polyseal caps. No one has mentioned the film to be processed. I've not run tests but my understanding is that high speed films require more chemistry than slow speed films. An aside: FX-1 results have been reported to be very nearly the same as Rodinal's. I think both can be considered high ph, very active, compensating developers and the more compensating the higher the dilution. I'm with you on the amount of chemistry although 10ml may be more than enough for most occasions. I'd steer clear of the give or take a .1 or .2 ml. for the purpose of contrast control. After all the amount of silver to be reduced will vary from roll to roll. Likely the best approach is to vary the dilution. Using an oversize tank has been suggested and one I've adopted when using FX-1. Dan Keep in mind that some plastics admit oxygen through the plastic (some by design, the rest by accident), and thus are not good for storing chemicals. > Keep in mind that some plastics admit oxygen through the plastic (some by > design, the rest by accident), and thus are not good for storing > chemicals. but if you put strong alkali into glass bottle, it will resolve the inner wall. So Rodinal should be kept in a plastic bottle, like it comes from Agfa. muchan And what about the brown glass bottles they used to at least the middle 70's? Jorge >> Keep in mind that some plastics admit oxygen through the plastic >> (some by design, the rest by accident), and thus are not good for [quoted text clipped - 5 lines] > > muchan >>>Keep in mind that some plastics admit oxygen through the plastic >>>(some by design, the rest by accident), and thus are not good for [quoted text clipped - 10 lines] > > Jorge I don't know.. maybe there wasn't better container than glass at that time, or maybe the glass etching effect of Rodinal doesn't affect the developement, or maybe Rodinal isn't so strong alkali as I thought. I know that Rodinal contain a lot of KOH, and it's chosen over NaOH for higher concentration, so I assumed it must be very high pH. Do you know its pH? muchan (ignoramus sum) Rodinal is an interesting dev. First, the exact formula is not known, and changes made during it's long life are not known, also. But from the public formula, the KOH (or NaOH) is partially neutralized by a lot of potasium metabissulfite so pH is not as high as it may seem. Do a search in Google GROUPS (not plain google) for "Gudzinowicz Rodinal Formula" without the quotes and you will find a very interesting article (by a PhD in chemistry...) Jorge > > And what about the brown glass bottles they used to at least the > > middle 70's? [quoted text clipped - 11 lines] > > muchan (ignoramus sum) > Rodinal is an interesting dev. > First, the exact formula is not known, and changes made during it's long > life are not known, also. "...and changes made..." I think no substantive changes have been made. Perhaps the make up has changed a little due to production improvements in the chemicals which make up the Brew. > But from the public formula,... Formulary Rodinal and Jacspks ?, both have the same formula: 50 grams p-AM, 150 grams K2S2O5, 215 grams KOH, per liter. That formula is Way Way different than Agfa's formula for Rodinal: ?? grams p-AM, ?? grams K2SO3, 30 grams KOH, per liter. BIG Difference! Has Agfa forgotten the formula for Rodinal? For film developers the two formulas are not even close. Unless that is, the public formula is seven times the strength. How about, dilute 1:700. > Do a search in Google GROUPS (not plain google) for "Gudzinowicz Rodinal > Formula" without the quotes and you will find a very interesting article > (by a PhD in chemistry...) Jorge That will take some study. Dan Thre is somewhere in R.P.D. another very intersting posting from M. Gudzinowicz in which he expain the 'why' of the K/NaOH-metabissulfite mix. Very interesting if you can locate it. Jorge >> Do a search in Google GROUPS (not plain google) for "Gudzinowicz >> Rodinal Formula" without the quotes and you will find a very >> interesting article (by a PhD in chemistry...) Jorge > > That will take some study. > Dan >Thre is somewhere in R.P.D. another very intersting posting from M. >Gudzinowicz in which he expain the 'why' of the K/NaOH-metabissulfite >mix. >Very interesting if you can locate it. > >Jorge Do you mean this post? (hope you don't mind Micheal) The following recipe was from an old text... unfortunately I lost the reference years ago, but it works. Rodinal Preparation: Boil 250 ml water and add a few crystals of potassium metabisulfite, followed by 20 g of para-aminophenol hydrochloride. After the para-aminophenol-HCl dissolves, add 60 g potassium metabisulfite, and stir until dissolved. Then add a solution of 40% (w/v) sodium hydroxide which thickens the solution as the para-aminophenol base precipitates, and then goes back into solution as the phenolate anion as more sodium hydroxide is added. Stop the addition of sodium hydroxide while there is still a small amount of precipitate left, and add water to make 400 ml. Set aside to cool, and place in a glass bottle. A small amount may come out of solution, but the addition of sodium hydroxide will dissolve it. If there is no precipitate, excess sodium hydroxide may be present, and a saturated potassium bisulfite solution may be used to neutralize it. (The amount of 40% sodium hydroxide required is approx 70 ml.) A small amount of precipitate is desired, since this occurs at the lowest pH at which the para-aminophenol is in solution. The addition of more base results in a higher pH at which the solution oxidizes more rapidly. When I purchase Agfa's Rodinal (to avoid mixing it from scratch), I titrate it with a saturated solution of sodium bisulfite until a few crystals appear, and then divide it into glass bottles for storage. I've kept some small samples around for 4-5 years, and they still had the same activity as the original solution when stored in this manner. The product sold by Agfa appears to be quite basic, which might make it easier to handle, but reduces longevity. -- Mike in RI / Internet: ab366@osfn.rhilinet.gov michael.gudzinowicz@enest.com > Do you mean this post? (hope you don't mind Micheal) > [...] [quoted text clipped - 4 lines] > Mike in RI / Internet: ab366@osfn.rhilinet.gov > michael.gudzinowicz@enest.com para-aminophenol hydrochloride. potassium metabisulfite sodium hydroxide Interesting. Interchange "sodium" with "potassium" and that would the Photographer's Formulary chemistry but with sligtly different proportions. Typo in the post? No, it's another one in which M.G. comments that the process of slowly adding alkali to the solution until paraminophenol almost solve completelly was a very clever idea of old time Agfa to adjust pH without using a pH meter or the like. Re the post you presented, see his comments that Rodinal nowadays is more alkaline than it used to be - so, that maybe one of the small changes made over its life Jorge >>Thre is somewhere in R.P.D. another very intersting posting from M. >>Gudzinowicz in which he expain the 'why' of the K/NaOH-metabissulfite [quoted text clipped - 4 lines] > > Do you mean this post? (hope you don't mind Micheal) > Thre is somewhere in R.P.D. another very intersting posting from M. > Gudzinowicz in which he expain the 'why' of the K/NaOH-metabissulfite I have a bottle of Rodinal in front of me. The bottle was purchased no more than four years ago. The contents are: potassium sulfite, hydroxide, bromide, and p-aminophenol. There is NO bisulfite or metabisulfite. Other than the p-AM all are compounds of potassium and there are NO bi or meta sulfites. Public domain "Rodinal" is NOT even close to Agfa's Rodinal. Dan > Public domain "Rodinal" is NOT even close to Agfa's Rodinal. Dan I would say that it is close but not identical. As Michael noted, the distributed version is very basic which indicates that it may have less bisulfite in it. Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email Besides, the MSDS cites pot. bromide, not in the public formula. But this could have been one of those small changes - more alkali, put some bromide to avoid fog. Jorge >> Public domain "Rodinal" is NOT even close to Agfa's Rodinal. Dan > [quoted text clipped - 6 lines] > John S. Douglas, Photographer - http://www.darkroompro.com > Please remove the "_" when replying via email > > Rodinal is an interesting dev. > > First, the exact formula is not known, and changes made during it's long [quoted text clipped - 19 lines] > > That will take some study. Dan I see one possible reason for the difference. AGFA gives the constituents that are left after all the reactions that go on when they mix the ingredients. By the time the KOH has reacted with the Potassium metabisulfite and the p-aminophenol.HCl to give potassium sulfite and p-aminophenol, all that's left of the KOH is 30 grams, I reckon. >Unless that is, the public >formula is seven times the strength. I believe the original formula was published around 1905 Water @ 125F 750ml p-Aminophenol Hydrochloride 100g Pot. metabisulfite 300g Water to make 1.0L 50% Hydroxide Solution Water @ 65F 75ml Sod. Hydroxide 50 Water to make 100ml From my site of course ;>) Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email > I believe the original formula was published around 1905 > [quoted text clipped - 9 lines] > > From my site of course ;>) Nice site but where are the galleries? One other formula of a Rodinal type has been posted this thread. Perhaps you saw it: 20gr p-AM, 60gr metabisufite, and 28gr KOH per 400ml. A complete discription of it's compounding is included. Contrast that mix with Formulary's 50gr, 150gr, and 215gr per 1000ml. On a liter basis the above posted formula has 70gr of KOH. Where does the Formulary and Jacks Pic come up with 215gr? Am I over-looking something somewhere? I've not done the arithmatic yet but would not be surprised if the 70gr gives the 3% KOH Agfa claims on their bottle. Dan > > I believe the original formula was published around 1905 > > [quoted text clipped - 21 lines] > yet but would not be surprised if the 70gr gives the 3% KOH > Agfa claims on their bottle. Dan Dan, The standard abbreviation for grams is "g". The abbreviation "gr" stands for grains. I'm sure you meant grams. Some Englishman might not be sure. I have used the Formulary kit. When you mix that, you do not necessarily use all of the KOH. You are instructed to add it little by little until only a few crystals are left. If you are dealing with USP chemicals, perhaps you can specify exact amounts of each chemical that will leave a few crystals. Photography does not, as a rule, need nor even profit from the use of USP chemicals, or scales that weigh to the milligram, either. If you can do what amounts to titration until an observable reaction happens, there are lots of uncertainties you can work around. Anything I say here is my opinion. I don't have the fear of failure that some others do, but my experience has been that as many failures happen when I follow to the letter another's instructions as when I use my teaspoons and "salt to taste". I'm preaching anyway, aren't I. >> I believe the original formula was published around 1905 >> [quoted text clipped - 11 lines] > > Nice site but where are the galleries? LOL ! It's turned out to be a rather busy year for me ! Do you have children ? Also note that I'm adding the "noframes" section which is another 1400+ pages to get working. > One other formula of a Rodinal type has been posted this thread. >Perhaps you saw it: 20gr p-AM, 60gr metabisufite, and 28gr KOH per >400ml. A complete discription of it's compounding is included. > Contrast that mix with Formulary's 50gr, 150gr, and 215gr per >1000ml. On a liter basis the above posted formula has 70gr of KOH. >Where does the Formulary and Jacks Pic come up with 215gr? The 215 gram of KOH is mixed into 500ml of water to give the 21.5% solution used to titrate the stock. The percentage doesn't matter that much though it might have been used for saftey concerns as a 50% stock soluton of KOH could be real nasty. Also note that one will usually use virtually the same amount of alkali to titrate a given quantity of acid. I say "virtually" as the strength of bisulfite seems to vary a little unless one is consistently using fresh chemicals. Regarding where the 215g figure came from, unfortunately I can't find a source. > Am I over-looking something somewhere? I've not done the arithmatic >yet but would not be surprised if the 70gr gives the 3% KOH >Agfa claims on their bottle. Dan 70gr is quite a bit of KOH. Also aren't their bottles 500 ml ? Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email > > Am I over-looking something somewhere? I've not done the arithmatic > > yet but would not be surprised if the 70gr gives the 3% KOH > > Agfa claims on their bottle. Dan > 70gr is quite a bit of KOH. Also aren't their bottles 500 ml ? I've read Dr. M. Gudzinowicz lengthy post where-in he compares one of your concoctions with Rodinal. In his conclusion he makes the observation that the new Rodinal has no "sludge". Although he is unclear I believe he is saying that the ph has been uped. I think that may account for the 3% KOH. That is only .3g/liter at 1:100 or .005 molar. He is not happy with that. How much that raises the ph I could'nt say. Metol, p-AP, and Glycin now make-up my list of developing agents which will do it all, film/print, acting individualy. My minimalist approach may be rewarding. Dan > > > Am I over-looking something somewhere? I've not done the arithmatic > > > yet but would not be surprised if the 70gr gives the 3% KOH [quoted text clipped - 12 lines] > agents which will do it all, film/print, acting individualy. > My minimalist approach may be rewarding. Dan Where is that post by M. Gudzinowicz? Did he compare one of my concoctions with Rodinal? Pat Gainer Patrick These are old posts, and AFAIR he did not do any compare of yours concoctions with Rodinal (more even so if you're thinking of PG). They have been posted in R.P.D. about 1999~2000. Jorge Patrick Gainer <pgainer@rtol.net> wrote in news:406728DB.14D0D166 @rtol.net: > Where is that post by M. Gudzinowicz? > Did he compare one of my concoctions with Rodinal? > > Pat Gainer > Where is that post by M. Gudzinowicz? From this NG search for, "my home brew" . The doctor is number one. > Did he compare one of my concoctions with Rodinal? He has positioned one of Mr. J. Douglas' formulas on the operating table and proceeds to dissect it. Dan > From this NG search for, "my home brew" . The doctor is number >one. Boy do I remember that thread ! Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email >>>> Am I over-looking something somewhere? I've not done the arithmatic >>>>yet but would not be surprised if the 70gr gives the 3% KOH [quoted text clipped - 17 lines] > > Pat Gainer Patrick, I read MG's post and it was interesting that he went into the concept of how to maximize the amount of p-aminophenol in Rodinal. I also read your article where you talk about dissolving some developing agents in hot TEA to obtain very long lived stock solutions. I wonder if p-aminophenol can be dissolved in this way and what the results would be. Perhaps the grain can be tamed this way? Just speculating, I am not a chemist. Bert > Patrick, I read MG's post and it was interesting that he went into the > concept of how to maximize the amount of p-aminophenol in Rodinal. I [quoted text clipped - 4 lines] > > Just speculating, I am not a chemist. Bert, I am not a chemist either but I have tried and used for awhile what you are talking about. Well, not exactly but close. I made a concoction of Propylene Glycol and p-Aminophenol (with the weights for p-Aminophenol.HCl as well) and Vitamin C and gave the ingredients for it in the pdf I made of Patrick's developers. I had been using the water based version for some time and enjoyed the very fine grain and sharp looking prints I got from it. However I could not get the developer to last in concentated solution reliably for more than a couple of months without some kind of loss of activity. For this reason I stopped using this developer. However sometime last year I tried concocting something with the new 'base', first with antifreeze (ethylene glycol) and then with propylene glycol. I got good results and used it for awhile (some months) to good effect. For some reason the grain seemed even finer than with the water based developer... Whether or not TEA works I dont know, worth a try however... Email me without the capital letters and I will forward the pdf onto you if you would like to try it. Regards, Nicholas >> Patrick, I read MG's post and it was interesting that he went into the >> concept of how to maximize the amount of p-aminophenol in Rodinal. I [quoted text clipped - 29 lines] > Regards, > Nicholas Nicholas, I received the pdf and found it interesting. I will add it to my list of things to do or try. Thanks a million! Bert > I believe the original formula was published around 1905 > [quoted text clipped - 7 lines] > Sod. Hydroxide 50 > Water to make 100ml That sodium 50g/40 ratio is close to the potassium 70g/56 I mentioned in my last post. The 40 and 56 are the gram formula weights. Yet the formula above has twice the p-AP and 85g more K. metabisulfite of any formula yet encountered for a Rodinal type developer. So the above formula has, by comparison , very little Na or K OH. Also the above formula does not maintain the same ratio of other Rodinal types when p-AP and metabisulfite are compared. All that acid and so little OH. I doubt the above formula will work. BTW, another p-AP product on the market is Calbe R-09. Dan > > I believe the original formula was published around 1905 > > [quoted text clipped - 15 lines] > Also the above formula does not maintain the same ratio of other Rodinal > types when p-AP and metabisulfite are compared. Correction: ...the above formula DOES maintain the same ratio... Dan > All that acid and so little OH. I doubt the above formula will work. > BTW, another p-AP product on the market is Calbe R-09. Dan [Why doesn't Rodinal etch glass?] > I don't know.. > ... the [concentration of KOH] in Rodinal. > muchan (ignoramus sum) 1) It is a 3% solution of KOH - it says so on the label. It has to be hot and concentrated to do a decent job of etching glass. Plastic is preferred for transporting nasty stuff as it won't break when the bottle (or the box the bottle is in) is dropped. And the bottle is _always_ dropped. FWIW: Pure water will etch glass - http://home.t-online.de/home/Bernhard.Hiller/fraud-01.htm  SignatureNicholas O. Lindan, Cleveland, Ohio nolindan@ix.netcom.com Consulting Engineer: Electronics; Informatics; Photonics. psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ So, can we store Rodinal in brown glass bottles? >So, can we store Rodinal in brown glass bottles? If you want to, nobodys going to come and arrest you for it. ;-) I would think the only thing missing would be the rubber stoppers it used to come with. I don't know how well the hard plastic lids will seal. The paper liners commonly found in them die quick with harsh alkalies present. The slightly soft ones on the plastic bottles seal up pretty tight. > >So, can we store Rodinal in brown glass bottles? > > If you want to, nobodys going to come and arrest you for it. ;-) > I would think the only thing missing would be the rubber stoppers [...] Stoppers, stoppers. I'll pick some up. > >So, can we store Rodinal in brown glass bottles? > [quoted text clipped - 4 lines] > alkalies present. The slightly soft ones on the plastic bottles seal > up pretty tight. Someone sugested using the medicine measuring syringes that look like a hypodermic and come with a soft plastic stopper with a hole in it. I trim one of these till only one ring protrudes from the bottle and drill a hole in the bottle's screw cap to let the nozzle come through, then screw the cap on permanently. I leave the syringe in the stopper between times as a seal. This is convenient. > Someone sugested using the medicine measuring syringes that look like a > hypodermic and come with a soft plastic stopper with a hole in it. I > trim one of these till only one ring protrudes from the bottle and drill > a hole in the bottle's screw cap to let the nozzle come through, then > screw the cap on permanently. I leave the syringe in the stopper between > times as a seal. This is convenient. Can't picture it, but there are plastic 'accordian' shapped syringes intended specifically for chemicals. They aren't stoppers. They let oxygen into the bottle. Beware if that's what you are using. > > Someone sugested using the medicine measuring syringes that look like a > > hypodermic and come with a soft plastic stopper with a hole in it. I [quoted text clipped - 6 lines] > intended specifically for chemicals. They aren't stoppers. They let oxygen > into the bottle. Beware if that's what you are using. Not to brag or anything but my developer stock solutions are not affected by oxygen. I've not seen any evidence except color change that Rodinal is either. I'm sloppy enough to have seen it, I assure you. > > > Someone sugested using the medicine measuring syringes that look like a > > > hypodermic and come with a soft plastic stopper with a hole in it. I [quoted text clipped - 10 lines] > affected by oxygen. I've not seen any evidence except color change that > Rodinal is either. I'm sloppy enough to have seen it, I assure you. I should have specified currently concocted stock solutions, the ones with no water. (jjs) wrote: > > So, can we store Rodinal in brown glass bottles? They are brown and also amber. I think more commen is, Boston Round amber glass bottles. I've a bunch from three sources, one of which is out of business. Tri Ess Sciences and eBay are the other two. My last bunch came from Tri Ess and were dark brown, sorry to say. I like to do some business with them. They've a lot of stuff for the Homebrew crowd including chemistry so will be back to them. CAPS, bottles need caps. I've posted this once this thread and other threads as well. Polycone or Polyseal caps are the only caps to have. As the name implies the caps have a conical, wedgeing insert which seals and lasts. Think of a rubber stopper and how it wedges into the neck of the bottle then add a screw cap to keep it there. Your source for caps is Tri Ess. They have a large variety of caps. Dan > I don't know how well the hard plastic lids will > seal. The paper liners commonly found in them die quick with harsh > alkalies present. The slightly soft ones on the plastic bottles seal > up pretty tight. >So, can we store Rodinal in brown glass bottles? Only if you promise not to drop them ... > So, can we store Rodinal in brown glass bottles? Only if you stop swigging from them and then postiing nasty replies to SS on rec.photoequipmentlargeformat. :-D SignatureRun down to Bob Storches they handle lights for all occasions. > [...] if you put strong alkali into glass bottle, it will resolve the inner > wall. So Rodinal should be kept in a plastic bottle, like it comes from Agfa. I'm sure others want to know: Keeping Rodinal concentrate in a glass bottle is a Bad Thing? [] true [] false > I'm sure others want to know: > Keeping Rodinal concentrate in a glass bottle is a Bad Thing? > > [] true > [] false IS TRUE Glass has been used for centuries. Be sure it is not "green glass". Hydrofluoric acid is kept in quartz bottles. That acid is used to etch glass. If and I say IF glass etches at all when used with photo chemicals, the products of the etching are extremly minute and I don't believe of any consequence and that is IF there are any to start with, which I doubt. Dan > > [] false IS TRUE > [quoted text clipped - 5 lines] > I don't believe of any consequence and that is IF there are > any to start with, which I doubt. Dan Thanks for that, and your other post, Dan. I had an awful time finding small glass bottles. Even the pharamcists quit using them. So I ordered from Boston Round and by your post it appears that I guessed well. >Thanks for that, and your other post, Dan. I had an awful time finding >small glass bottles. Even the pharamcists quit using them. So I ordered >from Boston Round and by your post it appears that I guessed well. Why not just use the 250~300 ml plastic cough syrup bottles that any pharmacy has ? I believe that most are made of PET which is an excellent storage medium. Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email On 3/25/2004 11:33 AM John spake thus: >>Thanks for that, and your other post, Dan. I had an awful time finding >>small glass bottles. Even the pharamcists quit using them. So I ordered [quoted text clipped - 3 lines] > that any pharmacy has ? I believe that most are made of PET which is > an excellent storage medium. Now's as good a time as any to bring up this sticky question: just how permeable *are* plastic bottles, anyway? I hear it said, over and over again like a mantra, that plastic bottles are no good because they let oxygen through. But is this really true? And is it true for *all* plastics? I suspect not, but can't say for sure since I'm not a plastics expert. What is the permeability of various plastics? PET? HDPE? others? Anyone know for sure? Signature... but never have I encountered a guy who could not be bothered to make his own case on his own show. - Eric Alterman on his appearance on Dennis Miller's bomb of a show on CNBC (3/17/04) Check out Ryuji's site: http://silvergrain.org/Photo-Tech/chemistry-misnomers.html He is a chemist. _________________ Ready, Fire, AIM. Bruce Brooklyn, N.Y. On 3/27/2004 12:12 PM Bruce spake thus: > Check out Ryuji's site: > > http://silvergrain.org/Photo-Tech/chemistry-misnomers.html > > He is a chemist. Thanks. From his page on plastic bottles (http://silvergrain.org/Photo-Tech/plastic.html): Why manufacturers and chemists recommend glass bottles for storing photographic chemicals has a lot to do with idiot-proof factors. With a little attention, inexpensive and convenient plastic bottles can be used for most photographic chemical storage without compromising their shelf life. Plastic materials and chemical properties material gas permeability acid resistance max usable temp --------------------------------------------------------------- PET (PETE) very good reasonable 60°C HDPE poor good 120°C PVC very good reasonable 70°C LDPE very poor good 80°C PVdc (Saran wrap) excellent reasonable 65°C PET (polyethylene terephthalate) is used as a clear (colorless or tinted) bottle material in bottled water products. It has very small permeability to oxygen and nitrogen. Use PET for developers. Use PET or HDPE for most other chemicals. If you store acetic acid stop bath in concentrated form, use HDPE. If PVC coated cap is available, use it by all means. My bottles of D-76, Microphen, and various other experimental formula are still alive and as vigorous in filled and tightly capped 500ml PET bottles after two years! So take that, ye who say that only glass can be used to store photo chemicals! Signature... but never have I encountered a guy who could not be bothered to make his own case on his own show. - Eric Alterman on his appearance on Dennis Miller's bomb of a show on CNBC (3/17/04) > Why manufacturers and chemists recommend glass bottles for storing > photographic chemicals has a lot to do with idiot-proof factors. With a [quoted text clipped - 11 lines] > LDPE very poor good 80°C > PVdc (Saran wrap) excellent reasonable 65°C Glass excellent excellent way up there > So take that, ye who say that only glass can be used to store photo > chemicals! I added a line. I hope you don't mind. What ever is used be sure the caps are of the Polycone/Polyseal type. Dan >> Why manufacturers and chemists recommend glass bottles for storing >> photographic chemicals has a lot to do with idiot-proof factors. With a [quoted text clipped - 13 lines] > > Glass excellent excellent way up there So you can use HDPE or even LDPE, just wrap it in Saran wrap? :-) > >> Why manufacturers and chemists recommend glass bottles for storing > >> photographic chemicals has a lot to do with idiot-proof factors. With a [quoted text clipped - 15 lines] > > So you can use HDPE or even LDPE, just wrap it in Saran wrap? Or a wide mouth glass jar. Jars take lids and I've not seen any Poly seal/cone lids. I know, those canning rings with seal equipped lids should work. I think they are made in gallon size. Dan it is true to any plastic. relevant values are in many reference books dealing with plastics or packaging. try uni library. >On 3/25/2004 11:33 AM John spake thus: > [quoted text clipped - 13 lines] >I suspect not, but can't say for sure since I'm not a plastics expert. What is >the permeability of various plastics? PET? HDPE? others? Anyone know for sure? On 3/24/2004 2:57 AM Dan Quinn spake thus: >> I'm sure others want to know: >> Keeping Rodinal concentrate in a glass bottle is a Bad Thing? [quoted text clipped - 4 lines] > Glass has been used for centuries. Be sure it is not "green > glass". What's wrong with green glass? contains metals? Signature... but never have I encountered a guy who could not be bothered to make his own case on his own show. - Eric Alterman on his appearance on Dennis Miller's bomb of a show on CNBC (3/17/04) > > Glass has been used for centuries. Be sure it is not "green > > glass". Dan > What's wrong with green glass? contains metals? Recycled may have been a better word. Recycled will likely contain more impurities. Iron is common. Parts per billion and even less of several metals can shorten solution life. Those "dark brown" Boston Rounds purchased from Tri Ess Sciences are actually dark amber. Not so bad after all. I may take a likeing to them. Tri Ess also carries clear glass Boston Rounds and the Polyseal caps to go with them. Dan > > What's wrong with green glass? contains metals? > > Recycled may have been a better word. Recycled will likely contain > more impurities. [...] I'll never drink Heinekin again. >> Recycled may have been a better word. Recycled will likely contain >> more impurities. [...] > >I'll never drink Heinekin again. They just add to the flavor ;>) Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email > >> Recycled may have been a better word. Recycled will likely contain > >> more impurities. [...] > > > >I'll never drink Heinekin again. > > They just add to the flavor ;>) You are the man to ask: Have you noticed that Rodinal concentrate looks just like Guinness? Did you discover it the hard way? :) >You are the man to ask: Have you noticed that Rodinal concentrate looks >just like Guinness? Did you discover it the hard way? :) Ummmm, now that we have children, I tend towards something a little more caffeinated. To all of those that warned to get some sleep, YOU WERE SO RIGHT !! And yes, Rodinal does remind me of coffee ;>) Regards, John S. Douglas, Photographer - http://www.darkroompro.com Please remove the "_" when replying via email > Hi all, > [quoted text clipped - 6 lines] > I do not develop not more than 1-2 rolls of film in a week, shelf life is > important to me. Seen this? http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=004r8U I know alot of you might have, here it is just in case it provides some use... > > Hi all, > > [quoted text clipped - 11 lines] > I know alot of you might have, here it is just in case it provides some > use... Nobody answered Dan's question about using p-aminophenol HCL with carbonate. I have seen recipes for such. You will not be able to get a concentrated stock solution, though. This one is in the War Department Technical Manual of Photography, listed as a tropical developer (1941 edition); Water 96 ounces. p-aminophenol.HCl 400 grains sodium sulfite 6 ounces, 290 grains sodium carbonate (anh) 6 ounces, 290 grains Water to 1 gallon. Use full strength 7 to 9 minutes in tray at 65 F, 3 to 4 minutes at 80 F. Tese times were, of course for 1940 films. > > > Hi all, > > > [quoted text clipped - 26 lines] > > Tese times were, of course for 1940 films. A little off topic, but did you fellows hear about the joker who almost got some city council to ban the use of paper cups containing dihydrogen monoxide? It was described as a colorless, tasteless, odorless liquid that could be fatal if inhaled. > A little off topic, but did you fellows hear about the joker who almost > got some city council to ban the use of paper cups containing dihydrogen > monoxide? It was described as a colorless, tasteless, odorless liquid > that could be fatal if inhaled. Yeah, it was a school project that was to test gullibility. :-) > Hi all, > > I do not develop not more than 1-2 rolls of film in a week, shelf life is > important to me. I don't use a lot of it, but my bottle I dated 24/12/01 on opening is still fine, although alomst empty. > I have another question. I use 300 ml of working solution to develop 35 mm. > films. the 1+50 dilution requires really little amounts of stock developer. > Is there a threshold for the stock amount to be used, any minumum limits? Numbers get bandied around, official and unoffical. I personally use Rodinal 1:100 so use 3ml in 300ml for 35mm. 5ml in 500ml for MF. I have played around with 1:400 (0.75ml in 300ml) for stand development (which worked) Cheers, Nige |
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