Obsidian Aqua, catechol staining developer

[steveo]

Okay I think I've got my head round it.

Working should be 5g/l, (this) stock is 200 g/l, so 1l would have 25ml of the working solution; 500ml would need 12.5ml

[Taija71A]

Okay I think I've got my head round it.

Working should be 5g/l, (this) stock is 200 g/l, so 1l would have 25ml of the working solution; 500ml would need 12.5ml

__

Excellent!

12.5ml is... The 'Correct' answer.
(*I of course could of told you the answer...
But you now have the 'Satisfaction' of being able to figure it out -- Yourself!).
--
Best regards,

-Tim.
_________

[steveo]

And of course if I mess with the B stock solution I can work out my own variables.

[Taija71A]

And of course if I mess with the B stock solution I can work out my own variables.

Exactly!

[steveo]

Is there a practical limit to how much Sodium Carbonate can be dissolved in water?

[Taija71A]

Is there a practical limit to how much Sodium Carbonate can be dissolved in water?

__

Yes... Approx. 200g/L.
_______

[steveo]

__

Yes... Approx. 200g/L.
_______

Fair enough

[Regular Rod]

Can I ask a newbie question. If I bought a 2kg bag of Anhydrous Sodium Carbonate how much solution B would this make and how much of it would I add to the working solution? Also the working solution looks something like 1ml of A to ??ml of b topped off with water to make 500ml?

Edit: Found an earlier post by Regular Rod which suggests 1kg of the Carbonate to make 5l then using it 1:12.5 topped up to 500ml have I read this correctly?

Yes.

RR

[steveo]

Got all my chemicals mixed the other day and done a test roll of GP3 at the weekend and it worked! Thanks for the help guys.

Need to get an inversion lid for my Jobo before I can start doing 54 with this stuff.

[Jon Wilson]

Resurrecting this thread and hope to bring it new life.
Does anyone have any additional developing suggestions for various films in a jobo? I just mixed up a liter of AO today and want to see what I can do.
Thanks. JW