Baking Soda Question

AgX

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you can easily convert your baking soda into sodium carbonate.
spread some out onto a cookie / baking sheet and put it in an oven
in low heat. you just want to purge the water out of it / dehydrate it/

2 NaHCO3
Na2CO3 + CO2 + H2O
 

Pixophrenic

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I know this comes too late, but for every gram Na2CO3 in the recipe mix 0.78 g NaHCO3 and 0.37 g NaOH (caustic soda, at Amazon). Much more reliable than using washing soda of unknown provenance. I hope this helps.
 

Fujicaman1957

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Find someplace that sells pools supplies. They sell sodium carbonate to raise PH. Look for some thing that says something like "PH Up"
 

GRHazelton

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Find someplace that sells pools supplies. They sell sodium carbonate to raise PH. Look for some thing that says something like "PH Up"
Of course the local pool supply store will want to sell you sodium carbonate by the bucket! I'd go for the baking soda and oven technique.
 

Pixophrenic

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Find someplace that sells pools supplies. They sell sodium carbonate to raise PH. Look for some thing that says something like "PH Up"

That is exactly what I started with and would now warn against. The required amount of decahydrate salt is about 2.7-fold that of anhydrous salt, and sodium carbonate in this source has a variable amount of bound water which also changes with storage, so I found a mix of baking soda and caustic soda to be more reliable.
 

removed account4

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Indeed, using decahydrate sodium carbonate in place of anhydrous is likely one of the common sources of failure with Caffenol.
i guess ... i always thought it was because people weren't able to find vit c and used "fruit fresh" or similar preserves making stuff with pectin ... or the wrong coffee.
to be honest, i have used waterlogged washing soda nearly from the beginning ( 10+ years) , but i guess i am off the hook
because i don't measure any of my ingredients. never had failure except for once, when i melted all my emulsion off
because i used 90ºF water .. ( yeah i know, not too swift ) i try to keep thngs simple and would never
use caustic soda &c to convert to wasingsoda, seems a bit over the top, but that's just me .. i use caffenol because
it is NOT over the top, its just ez pz no measuring needed and works with everything ...

OP sorry for the coffee-shop detour
 

Pixophrenic

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I think it is similar to the situation with water, depends very much on where you live. Also, with Caffenol there may have been over-enthusiastic statements, like that the cheapest coffee is the best and almost any would do. I found that at least in my location this is not exactly accurate, though I was able to find a cheap coffee that works well. In my case the soda was the biggest problem, especially that now it could also be confused with "safe bleach" (sodium percarbonate) sold in our naturopathic shops along with baking soda and washing soda.
 

removed account4

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yep sounds about right !
there is a lot of hoopla about a lot of stuff
and in the end its more like
experiment until you find which "stuff" works
where you live ... when i was in france years ago
i used a coffee named "el gringo" it was by far the cheapest
i found, and worked head over heals better than anything i had used
until i started roasting my own ...
its funny, i've recommended other developers and dilutions that i used
( pre caffneol days ) to friends, and they did what i did and contrast-scorched their film ..
so i know what works "here" might not work "there" //
have fun with your coffee !
 

Arklatexian

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I just checked Photographer's Formulary and if you buy 1/5/10 lbs of Sodium Carbonate Anhydrous, it gets progressively cheaper per pound, plus freight of course. To me, it is the Metol and Sodium Sulfite that makes things expensive. Now what does the super market have that can be substituted for Metol? Or even Sodium Sulfite?........Regards!
 

BAC1967

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I use Arm & Hammer Washing Soda but bake the water our of it for consistency. After baking it I store it in an air tight container so it doesn't absorb moisture from the air. I live in the Pacific Northwest, we have plenty of moisture in the air.
 

tezzasmall

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I'm in the UK too and I have found it easy to find Washing Soda in a few shops, including the local convenience store. It only cost a few pounds for a large bag and I have used it photographically a few times now without any drying out in the oven etc. So, much cheaper and much easier than all the carry on with Baking Soda.

Terry S
 

Pixophrenic

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To the best of my knowledge, Supermarket does not offer anything remotely useful as a developing agent. Developers made from soda and certain vitamins and supplements (quercetin, rutin) are extremely slow. A developer made of only soda and ascorbic acid is fast but too contrasty. A developer can be made from a highly alkaline solution of glucose, but it is extremely slow at useful concentrations. Caffenol and Parodinal remain the only useful options should the shops like PF and Artcraft go out of business. In the UK, I found, there are more options right now. Also some photo shops in London still sell chemicals. Sodium sulfite in a punch can be made from metabisulfite and caustic soda. The former is available in DIY brewer shops and on Amazon. My best bet is in the developers that contain little or no sulfite. Surprisingly, where film developers are concerned I have been able to find and test some solutions that produce surprisingly fine grain despite only 2 g/L sulfite or so. They, of course, cannot be stored as a single solution, but can be as two solution concentrate. I suppose the same is true for paper developers but have not actually tried.
 
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ewbank1

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I use Arm & Hammer Washing Soda but bake the water our of it for consistency. After baking it I store it in an air tight container so it doesn't absorb moisture from the air. I live in the Pacific Northwest, we have plenty of moisture in the air.
I am just starting out with Caffenol and bought Arm & Hammer Washing Soda. I am curious if anyone knows a typical moisture content of this particular brand?
 

BAC1967

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I am just starting out with Caffenol and bought Arm & Hammer Washing Soda. I am curious if anyone knows a typical moisture content of this particular brand?
I think it varies, that's why I started baking it. You can do your own test by weighing it before and after cooking it to get the moisture content. There are instructions for that in the Caffenol Cookbook: http://www.caffenol-cookbook.com/
 

Pixophrenic

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I am just starting out with Caffenol and bought Arm & Hammer Washing Soda. I am curious if anyone knows a typical moisture content of this particular brand?

Since Arm and Hammer does a pretty good job at hiding it, it is probably not regulated. What does your Caffenol recipe say? Just "washing soda" or "washing soda water-free" or something else? I'd suggest developing a short film clip with the amount of soda that is listed and another with twice as much. Depending on the result, you will know how much to use. If either of these experiments does not yield a good negative, you should change the coffee and start over.
 

darkroommike

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Re pool supplies, the are two carbonates sold to increase pH. The first is sodium carbonate, in the US it is the monohydrate. The second is usually labeled sodium hydrogen carbonate and it's the other stuff--sodium bicarbonate. Note that if you don't want to buy a big bucket, look for smaller home pool packaging of packages for hot tubs and spas rather than commercial pool quantities. Also a good source for sodium bromide, sold as a hot tub sanitizer, and a great substitute for potassium bromide.
 

Pixophrenic

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It is an interesting possibility, but you need to be more specific (cat #, brand etc). It is easy to purchase something you do not need at all in your developer. For example, LEISURE TIME Spa Disinfectant Brominating Tablets (45430A) contains several brom- and chlor-substituted hydantoins (together >60% by weight), and no sodium bromide. Perhaps PE could enlighten us, if hydantoin derivatives would be developing agents, restrainers or none of those.
 

darkroommike

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Or just read the label?
 

ewbank1

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I am just starting out with Caffenol and bought Arm & Hammer Washing Soda. I am curious if anyone knows a typical moisture content of this particular brand?
I heated 19.9 g of Arm and Hammer Super Washing Soda at 350F for 30 minutes and it lost 1.1 g of weight. With only an approximate 5% loss, the Arm and Hammer Super Washing Soda appears to be fairly pure sodium carbonate. Perhaps the small amount of moisture was picked up while packaging or sitting in the cardboard box.
 

Pixophrenic

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If one thinks, optimistically, that by baking you completely converted monohydrate into anhydrous (water-free) sodium carbonate, then all you need to do is to increase the amount of soda in your caffenol recipe by a factor of 1.05. There is no need to bake it every time you need to make a developer.
 

Pixophrenic

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Or just read the label?

The OP apparently also read the label, but the info was not there. The same may apply to more complex mixtures you get at pool supply store. There is no obligation to disclose the components, especially if they are not harmful.
 
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