Cyanotype mixing question

[kevin klein]

Is there a change in chemestry when adding the two chemicals to the same water rather than making two seperate solutions? When making small batches I just use one little papercup with 2.5 ml of water and add the two chems.

 

[pdeeh]

what do you mean "a change in chemistry"?

 

[kevin klein]

Does it change or affect how it works adding the citrate and fericyanide together in the same solution as opposed to combining two seperate solutions?

 

[ced]

Try it and see if it is problematic...
2 Authorities on the subject as it were, Read all about Cyano here:
http://www.christopherjames-studio....cesses/SAMPLE CHAPTERS/CyanotypeProcessSm.pdf

http://www.mikeware.co.uk/mikeware/New_Cyanotype_Process.html

 

[removed account4]

hi kevin
i'm no expert, and admittedly am utterly clueless compared to a lot of people
who use cyanotypes. that said, the fellow who has the video on making glass cyanotypes mixes everyting in the same pot
you are making small batches, i think it only poses a problem if you are storing it for
extended time periods pre-mixed. i know i have cyanotype paper i coated months ago, and
even though it was / is all in a light safe in a dark coldish room, it isn't the same as freshly coated paper.

 

[BrianShaw]

That's my thoughts too, with traditional cyanotype chemistry. I still haven't explored Muke Wares formulation.

 

[pdeeh]

Just something to hold in mind when thinking about solutions: concentrations and dilution ratios.

So ... I use a very traditional cyanotype recipe which calls for:

8% Potassium ferricyanide (i.e. 8g in 100ml water or proportionately for different volumes)
20% Ferric Ammonium citrate (i.e. 20g in 100ml water or proportionately for different volumes)

I take equal volumes of each solution, mix them and use them to coat the paper.

(different people recommend different stock mixtures and different mixing rations of course)

If I made 20ml of sensitiser I would take 10ml of each solution and mix them together.

This means that the concentration of each chemical in the final volume is halved (the dilution is doubled): it consists of 4% ferricyanide and 10% of citrate
(*remember that that each stock solution is being diluted by the other stock solution when you mix them)

Therefore, mixing 20ml of sensitiser by adding dry chemicals directly to 20ml of water requires one to use 0.8g of ferricyanide and 2g of citrate.

By the way, I've got quite decent electronic scales, but mixing 2.5ml shots of sensitiser by mixing in dry chemicals strikes me as incredibly fiddly and I'm not all all sure why anyone would want to do so - the weights required will be really tiny.

Stock solutions of ferricyanide and citrate keep more or less forever, though the latter needs something to stop it growing mould ("Original" Listerine is often suggested, and I use a drop or two of 10% thymol in isopropyl alcohol)

[I am now going to sit back and wait for someone who really understands chemistry, dilutions and whatnot to point out that I have completely misunderstood everything and explain why, and I'll feel an utter buffoon]

 

[JPJackson]

The "Ware" cyanotype sensitizer is only one solution.

 

[pdeeh]

the op referred to mixing two chemicals. I'm not sure what Mike ware's process has to do with it except that ced.'s post linked to ware's site

 

[kevin klein]

Pdeeh, I was wondering of thymol would an option for stopping mould groth, I have plenty thymol and will add it to the FAC solution. Thanks. That will save time from mixing a new solution all the time.

 

[pdeeh]

I have plenty thymol

unusual.
I might surmise that you keep bees.
but I could be wildly off base.

 

[kevin klein]

Nope, no bees. I use it in the gelatin emulsions. How is it used in bee keeping?

 

[pdeeh]

it's used to control disease in hives.