Re: Obsidian Aqua, catechol staining developer
They dissolve in the distilled water at room temperature (say 20 deg. C) reasonably easily with stirring. You could speed the process by warming it up a little bit. Sodium Metabisulphite in first, dissolve all, then Catechol, dissolve all is the correct order.
RR
Re: Obsidian Aqua, catechol staining developer
Many thanks, much appreciated:)
Re: Obsidian Aqua, catechol staining developer
Hi
I wish to try Obsidian Aqua 1ml to 1 litre for Tech Pan, do I need to halve the sodium carbonate, ie 2.5 grams to 1 litre instead of the 5 grams required at 1 to 500 dilution?
Re: Obsidian Aqua, catechol staining developer
Quote:
Originally Posted by
Tony Lakin
Hi
I wish to try Obsidian Aqua 1ml to 1 litre for Tech Pan, do I need to halve the sodium carbonate, ie 2.5 grams to 1 litre instead of the 5 grams required at 1 to 500 dilution?
Yes. Put in half the amount of solution B as well. So...
Solution A 1ml into say 500ml of water then add 6.25ml of solution B then add water to make up to 1litre.
RR
Re: Obsidian Aqua, catechol staining developer
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?
Re: Obsidian Aqua, catechol staining developer
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Please read:
http://hypercatacutancedeveloper.blo...dian-aqua.html
The answers to your questions are clearly explained above. Thank-you!
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Personally, I would start by making something like a 20% Sodium Carbonate (200g/liter) Stock Solution.
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Regards,
-Tim.
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Re: Obsidian Aqua, catechol staining developer
Cheers Tim, that was the first one I stumbled across but I'm still a little confused by the second solution. Do you make up a large supply of very weak B instead of a stronger B?
Re: Obsidian Aqua, catechol staining developer
Quote:
Originally Posted by
steveo
... Do you make up a large supply of very weak B instead of a stronger B?
The Sodium Carbonate Stock (200g/liter) Solution (*That I suggest you make) ... Is your 'Stronger' B.
You of course, are 'free to make up' your Sodium Carbonate Stock Solution at a 'weaker' Dilution... But it won't keep as well.
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Cheers!
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Re: Obsidian Aqua, catechol staining developer
Right, missed that sorry.
So you have 1ml A + 100ml B + 400ml water?
Re: Obsidian Aqua, catechol staining developer
Quote:
Originally Posted by
steveo
... So you have 1ml A + 100ml B + 400ml water?
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No.
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As a 'Starting Point'... Your 'Working' Developer needs to contain approx. 5g of Sodium Carbonate per/L.
You just added 20g of Sodium Carbonate to your 500ml of Working Developer.
(*100ml/1000ml x 200g/liter) = 20g.
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Please get back with the correct amount of 'B' Stock Solution to add -- Okay?
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Thank-you!
-Tim.
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