Question on heating baking soda to make sodium carbonate

Discussion in 'Black and White' started by kc_dougherty, Jun 16, 2004.

  1. I want to make sodium carbonate from baking soda. In some of the
    posts here on, it says not to use an aluminum pan. In
    Patrick Gainer's article on unblinkingeye, it he doesn't say anything
    about what kind of pan to use, just be sure to use a lid on it.

    Also, how long do you heat it?

    Any tips or information would be greatly appreciated.

  2. Ok, I hate it when people don't answer the question, but I don't have a clue. I just bought a lifetime supply of carbonate for five bucks when buying stuff for the pool at our local hardware store. Ph increaser is nearly pure sodium carbonate (watch out, they sell bicarb for the same purpose- read the label) and works fine for photo use. It just isn't worth the trouble to heat bicarb and not be sure of what you've got, when the real thing is readily available for so little.
  3. That would be easier (buying the pool chemical) but making it as I need it saves me a storage problem. I may end up just buying the ready-made stuff but I wnated to try this.

  4. I'll agree with Conrad on this one, and further suggest that even in climates where few people have pools (and thus pool supply stores are few and far between) you can probably get sodium carbonate decahydrate of more than adequate purity in the grocery store. Go to the laundry aisle, look for Arm & Hammer Super Washing Soda, which is unscented and sold in a five pound box -- which is enough for about 500 single-roll batches of Caffenol, or somewhat more than 100 liters of most carbonate alkalized developers, and will cost you less than $4. While you're there, grab a box of 20 Mule Team Borax (should be right next to the washing soda), for another $2 or so, and you have all the photographic alkali you'll need for years to come unless you like Rodinal or find a formula that calls for metaborate or sodium hydroxide (which last you can find with drain cleaners for $6 a can, and react with the borax to make metaborate). If something calls for phosphate alkali, you're on your own...
  5. The washing soda would work? One of the developer formulas I use uses Borax and the 20 Mule Team works great.

    Thanks for the info...

  6. Well, you can heat baking soda if you want to. It's not a crime, or even a venial sin. I thought I said to use a stainless steel or Pyrex container. The lid should be a loose fitting one to allow gasses to get out. It's fun to watch the little volcanoes, but everything gets covered with powder if you do too much watching. The powder is a good cleaning agent for stove tops in any case.

    I used to use washing soda. It is harder to dissolve in cold water, and you must use more of it, about 2.7 times as much as anhydrous carbonate. I haven't been able to get it for years, which I think is strange because it had a lot of uses for country folk.
  7. I tried doing it last night and was able to keep a lot of the powder in the pot (cleaning up what little escaped was pretty easy). I'm not sure if the pot I was using was steel or aluminum but I mixed up a batch of your first version of the Vitamin C developer (sodium carbonate, vitamin C powder and phenidone) this morning and just "ran" a test roll of Tech Pan and the wet negs look good, so I must have done something right.

    How long did you heat the baking soda? I left it on fairly high heat for a few minutes (I'm not sure exactly how long, probably three or four)and "swirled" it from time to time. I left it in the pot overnight to give it time to cool off. I noticed condensation inside the lid of the pot after I took it off the stove.

    I've been using Chris Patton's E-76 formula because I wanted to stay away from using lye.

    In a posting a few months ago, you were talking about using glycerin for the phenidone and not alcohol. I tried it and although it was a little more difficult to dissolve the phenidone, I like it better because the developer then doesn't have the alcohol smell.

  8. When you swirl the pot, it feels like it has liquid in it untill the gasses are gone. A sure way to tell is to weight the baking soda before and after. For every 168 grams of baking soda you will get 106 grams of anhydrous sodium carbonate. That's about 10 oz per pound.
  9. Thank you.


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