washing soda

[seanE]

I'm going to make some caffinol-C, Now where do I get sodium carbonate, I have ''soda crystals'' Which underneath says in small weighting ''aka washing soda'' Then on the bottom it say contains sodium carbonate dehydrate, ''greater than 30percent''
If any one knows how to translate this wooly fluffy language id much appreciate it.
I would assume all that means it would not be suitable for chaffinol, However iv checked a lot of packets in my local stores and non of them mention close to 100percent,
I'm going completely :crazy:

 

[pdeeh]

It probably says decahydrate (which very precisely defines the composition and isn't at all woolly )

In which case, if you are following Reinhold's recipes or those in the caffenol cookbook, you will need 2.7x the amount specified in the formula of your decahydrate

 

[BAC1967]

I'm not sure where you are but in the U.S. I use Arm and Hammer Washing Soda. It's sold at most grocery stores with the laundry detergents. You can also convert Baking Soda (sodium Bicarbonate) to Washing Soda (Sodium Carbonate) by baking it in the oven at 250 degrees F for about an hour. Spread it out thin on a piece of aluminum foil to bake. There is a good write up in the Caffenol Cookbook about the needed ingredients.

http://www.caffenol-cookbook.com/

 

[Wayne]

Yup I user A&H Washing Soda too. It's monohydrate.

 

[Alan Johnson]

In the UK washing soda is the decahydrate and used to be so labelled.Thanks I believe to some inane EU regulation it is now labelled as greater than 30 %.

 

[pdeeh]

In the UK washing soda is the decahydrate and used to be so labelled.Thanks I believe to some inane EU regulation it is now labelled as greater than 30 %.

It is still labelled as decahydrate

 

[Alan Johnson]

It is still labelled as decahydrate

From some discount stores it is labelled >30%.I telephoned the manufacturer and was assured it is still the decahydrate.

 

[pdeeh]

In which case it is more accurate to say that some is labelled in the way you describe.

The most commonly found is the DriPak brand (in almost every supermarket) and it is clearly marked as decahydrate.

 

[Gerald C Koch]

Sodium carbonate monohydrate is the stable form at room temperature and is what is sold in the US. The decahydrate effloresces losing water to the air. Therefore the water content changes over time. You are also paying more to ship water.

When converting sodium bicarbonate to sodium carbonate you need to use a glass, stainless steel or agate pan. The process will attack any aluminum container and will also contaminate the finale product.

 

[seanE]

I made a two prints yesterday using a caffenol-C recipe using sodium carbonate
made by the bicarbonate of soda, To soda ash conversion method Gerald C mentioned above.
''it worked'' unbelievable,

The first print was washed out, I gave it 6 seconds of f4.5 on my enlarger'' The second I gave 3 and it turned out great. I thought it would give the print a sepia tone but it came out fairly B/W.