Adox Rodinal vrs RO-9 One Shot

Pioneer said:

Sorry I missed this. I use the formula posted by Donald Qualls. 30 Tylenol, 50 gr sodium sulfite, 20 gr sodium hydroxide. I let it stand for a couple of days and then filter it through a coffee filter to get some of the tylenol tablet filler material out of the mix. It begins to darken as it ages but that does not seem to effect how it works, bad or good. It works quite well for me and I use it at 1:25 and 1:50 at the times recommended on the Massive Development chart for Rodinal. I do make sure to shake it well before i mix it for use because there are crystals that form in the stock developer solution.

I will be picking up a bottle of Adox Rodinal but more as a backup if I have no time to mix my own batch. So far that has not been an issue. I only mix 250ml at a time so it does get used up pretty quick. I can't say if this formula has the same lasting qualities that Adox's Rodinal has. So far it hasn't gone bad on me though a batch or two have gotten pretty dark.

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the internet seems to swear by the use of LIQIOUD childrens tylenol... no solids... but can end up with other goop in it...

Pioneer said:

I only mix 250ml at a time so it does get used up pretty quick. I can't say if this formula has the same lasting qualities that Adox's Rodinal has. So far it hasn't gone bad on me though a batch or two have gotten pretty dark.

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I've kept the Parodinal concentrate as long as a year in a jelly jar with substantial airspace, and though as dark as coffee or Coca-Cola it still worked. If you mix 250 ml or even 500 ml at a time and it's your primary developer, you'll probably never find out how long it actually keeps. I wouldn't expect it to be quite as long as the old Agfa Rodinal -- or even homebrew made using the published method starting with p-aminophenol powder -- but it lasts as long as I've ever needed it to.

redbandit said:

LIQIOUD childrens tylenol

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That pretty much defeats the economy side of Parodinal -- even if you can find a generic it'll cost five times as much per gram of acetaminophen as the large bottles of 500 mg caplets.

Also worth noting that though I've never filtered my concentrate, I've never seen evidence of any problems caused by fillers or tableting agents; the sodium hyroxide breaks down waxes and starch even as it converts the acetaminophen to p-aminophenol. And filtering even as early as 2-3 days after mixing runs the risk of losing the crystals, which I understand to be mostly sodium sulfite that serves to keep the solution saturated in preservative.

Donald Qualls said:

I've kept the Parodinal concentrate as long as a year in a jelly jar with substantial airspace, and though as dark as coffee or Coca-Cola it still worked. If you mix 250 ml or even 500 ml at a time and it's your primary developer, you'll probably never find out how long it actually keeps. I wouldn't expect it to be quite as long as the old Agfa Rodinal -- or even homebrew made using the published method starting with p-aminophenol powder -- but it lasts as long as I've ever needed it to.


That pretty much defeats the economy side of Parodinal -- even if you can find a generic it'll cost five times as much per gram of acetaminophen as the large bottles of 500 mg caplets.

Also worth noting that though I've never filtered my concentrate, I've never seen evidence of any problems caused by fillers or tableting agents; the sodium hyroxide breaks down waxes and starch even as it converts the acetaminophen to p-aminophenol. And filtering even as early as 2-3 days after mixing runs the risk of losing the crystals, which I understand to be mostly sodium sulfite that serves to keep the solution saturated in preservative.

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in a bried search i only found a few people talking about NOT using the liqoud tylenol to make rodinal at home...

@Donald Qualls You can crush the pills, add acetone and filter the solution. You let it dry and you have paracetamol. This can be used to mix parodinal.

Anon Ymous said:

You can crush the pills, add acetone and filter the solution. You let it dry and you have paracetamol. This can be used to mix parodinal.

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And people worry about keeping sulfuric acid or sodium hydroxide in their darkroom! At the very least, keep the acetone in a vented flammables cabinet and do the evaporation under a fume hood; acetone vapor collects on the floor (significantly heavier than air) and can be ignited by the slightest spark once it does. Further, acetone is bad to inhale. A whiff won't hurt you, but prolonged inhalation can lead to kidney or liver damage.

While this is a chemically viable method to clean your acetaminophen/paracetamol, I'd say you're ahead to do your dissolution and filtration with water -- that is, stir/shake the solution as soon as you've mixed the crushed tablets with the water, then filter what you get and wash down the filtrate with more water (this will require starting with less than the formula's amount of water so you don't wind up diluting the solution too much). There will inevitably be some loss this way, however, and since it's difficult to measure the loss (or alternatively how much n-acetyl-p-aminophenol you actually managed to get into solution), you may find your developer weaker than expected. It ought to be possible to evaporate this solution as you'd do with a solution in acetone -- much slower, but a great deal safer -- and obtain crystalline acetaminophen you can measure by weight. Evaporating to get twelve grams of acetaminophen (which still makes only 250 ml of concentrate), however, implies a lot of solution that'll take a good while to evaporate (and I don't know if heat will alter the acetaminophen).

Even better would be to start with either technical grade paracetamol (para-hydroxyacetanilide is one name you can order -- watch out for minimum orders and "sold only to registered businesses!") or just buy p-aminophenol from DigitalTruth/Formulary or other chemical supplier. The latter will let you do the "titration" method of adding sodium hydroxide solution just until almost all the crystals dissolve and get a product that might be closer to mid-20th century commercial Rodinal, at least in terms of longevity.

@Donald Qualls Yes, evaporation of acetone should be done in a fume hood, or simply outdoors. And while sniffing acetone isn't a good idea, occasional use isn't the end of the world. I mean, ladies use it as a nail polish remover for ages and they definitely don't use special cabinets for storage either. Aqueous solutions of paracetamol could also be left to dry, but it will take too long and paracetamol will likely oxidise considerably. Starting with water at a high temperature, filtration and cooling will likely precipitate some pure paracetamol that could be used and weighed accurately. Not 100% of the dissolved quantity, likely most of it.

Anon Ymous said:

filtration and cooling

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That hadn't occurred to me; starting with 120F water (like you would to mix D-76) and then chilling with ice or even ice + salt to get the solution close to freezing should precipicate a high percentages of the chemical. Then, of course, you have to add the cost of the ice to the cost of your developer (if you have an ice maker, you're paying for the ice whether you use it or not, but those of us without even room in the freezer for an ice tray -- or water that makes cloudy/gritty ice -- buy it by the bag). I've gotten fine results by ignoring the tablet residue.

Of course, another way to deal with that is to just skim it off the finished developer. Mix as usual, starting from crushed tablets, but then let it stand for a couple hours in a beaker and you'll be able to skim off about 90% or more of the tablet residue (which floats on the solution) and remix the crystals from the bottom before decanting in to a storage bottle. You'll lose perhaps 5% of the developer, but that's nothing compared to buying/storing acetone or even paying for filter papers to filter the solution.

@Donald Qualls I wouldn't use ice, I'd just put the beaker in the fridge and freak out whoever opens it. Leave it overnight and marvel at it the next morning. Hey, that's what I do whenever I recrystallise stuff. Yes, there's a spare fridge that I can use cautiously for things like that. I also use regular coffee filters, they work fine and they're cheaper than dirt.

My fridge is usually too full to dare putting chemicals in. Coffee filters might work, they're thinner than normal chemical filter paper but we're not after filtering super-fine particulates.

If I find I have a need to remove the tablet fillers, I'll probably start by skimming and see if it's good enough.

Donald Qualls said:

or just buy p-aminophenol from DigitalTruth/Formulary or other chemical supplier.

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That does seem more direct than dissolving tablets. However, I found that p-aminophenol powder did not last well, turning very brown in a couple of years. Unlike other developing agents (glycin excepted)

john_s said:

Unlike other developing agents (glycin excepted)

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Metol will also darken over time, if exposed to air. This isn't very surprising, and likely isn't that big a deal, either, given that actual Rodinal made by the mid-20th century method will keep for literally years in a partially full bottle.

It is a good thing that photography is so forgiving.

Sounds like I have been doing all the wrong things for at least a couple of years but still getting good results. Since it all seems to work I doubt I'll change much. After pricing children's liquid tylenol I am pretty certain I won't be taking that route.

I use primarily Caffenol C, Parodinal and D-23 because they are easy to mix and I almost always have fresh developer to work with. I keep a bottle of L110 (generic HC110) around for those few times that I need it, which is not often.

Now all I need to do is start mixing up my own print developer that will work with Ilford's Multigrade fiber based paper and I'll be good to go.

Donald Qualls said:

Metol will also darken over time, if exposed to air. This isn't very surprising, and likely isn't that big a deal, either, given that actual Rodinal made by the mid-20th century method will keep for literally years in a partially full bottle.

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people have used bottles of rodinal that left the factory in the 1950s.... that stayed un opned... and had excellent and expected results with them in 2010.

Rodinal is like,,,,, the oscar mejer hotdog or twinkie of the photographic chemical world... the shit just LASTS...

John Wiegerink said:

I think you made a typo? Should be sodium sulfite and not sodium sulfate.

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True. It worked great