Cyanotype and mould

[brummelisa]

Hi,

I have just purchased my first cyanotype kit (the classic version) and I didn't knew that one has to prevent mould in sollution A.

In the instruction is says that I can use formalin. I went to my farmacist (sp) and the only thing they had was formaldehyd (I hope you understand what it is, but I think that they have mixed formalin with water or alcohol). The sollution is only 4%.

My question is will this prevent mould?

The instruction says that I should use 1ml (in a 50ml sollutin) of formalin, but I guess I have to add some more now?

I know about the newer Cyanotype, but I wonder what I can do now.

/ Marcus

 

[Jim Noel]

Formalin - formaldehyde - basically the same. Yes, either will work to prevent mold.

I must say that I have never added either to cyanotype and have kept some for 2-3 years without mold.

 

[brummelisa]

Thanks Jim,

In the instructions it said that it will create mould in a week or two and it sounded as after that I could not use it.

So before I stir it together I think that I need to know what to do.

/ Marcus

Formalin - formaldehyde - basically the same. Yes, either will work to prevent mold.

I must say that I have never added either to cyanotype and have kept some for 2-3 years without mold.

 

[Vaughn]

One can just filter out the mold (coffee filter should do the trick)...it still should be usable.

Otherwise...mix up only enough to use in a relatively short period of time. Since it is the classical formula, the part that molds is Ferric ammonium citrate -- no other chemicals (Part B is also just a single chemical, Potassium cyanide) You can then easily divide these into smaller amounts and add water to them proportionally instead of making up the whole kit.

Making sure the containers are clean before mixing might help delay mold forming. I suppose you could keep the Part A in the refridgerator, but with kids that may not be too safe.

Good luck and have fun!

Vaughn

 

[brummelisa]

I suppose you could keep the Part A in the refridgerator, but with kids that may not be too safe.

Vaughn

So you say that I will end up with two blue children now

/ Marcus

 

[Vaughn]

So you say that I will end up with two blue children now

/ Marcus

With the average temps in Sweden in the winter, that may be a given...

vaughn

 

[rwyoung]

You would be better off not having the formalin/formaldahyde around the house. It is more hazardous (when mishandled) than the cyanotype chemicals.

Get a good scale that can measure to 0.1g (more important that it be repeatable than accurate) and mix only small amounts. If the mold does show up, filter the solution through a coffee filter. It will work just fine afterward.

 

[Akki14]

I've had mould on my solution A. I just took a disposable wooden chopstick and fished it out (it kind of sticks to the wood). Strangely, it has never grown back, so I've never had a mould problem since . I've had the same solutions A & B since April this year.

 

[Photo Engineer]

Since it is the classical formula, the part that molds is Ferric ammonium citrate -- no other chemicals (Part B is also just a single chemical, Potassium cyanide)

Vaughn

Before we start a panic here, Cyanotype does NOT use Potassium Cyanide.

It uses Potassium Ferricyanide. This is an utterly different chemcial.

Neither part should mold appreciably, especially if you use boiled water or boiled distilled water.

PE

 

[Vaughn]

Thanks for catching that PE! I had the feeling something was wrong with that...but I got distracted by work.

Actually, I had "officially" finished my work day...but if students need help and I'm here, the work doesn't stop. (after all that is the fun part of my job!)

Vaughn

 

[smieglitz]

...Part B is also just a single chemical, Potassium cyanide...

Part B is Potassium FERRIcyanide, not potassium cyanide. Potassium cyanide is a deadly poison and is used in the wetplate collodion process by some. Potassium ferricyanide is much less toxic and until recently, I had always read that it was rather benign. It is the bleaching component in sepia toner.

You don't want to heat or mix acid with either compound because deadly hydrogen cyanide gas will evolve.

As far as the mold problem, I simply filter the pt. A solution to remove the mold. I've heard thymol will also help prevent it. A couple drops of Listerine antiseptic mouthwash would probably do the trick...

 

[Vaughn]

Thanks Smieglitz, PE caught that gaffe of mine a few hours ago. From what I understand it takes a pretty strong acid to break down Potassium ferricyanide -- stronger than working solutions of stop bath and fixers.

I would use Listerine before using Formalin - formaldehyde. I think PE's suggestion of boiled water is a good one -- perhaps sterilizing the container and measuring devices also.

vaughn

 

[brummelisa]

Thanks all for your input. I went to the farmacist yesterday and hoped I could buy some destilled water, but they only had sterilized water (which if I understand it is almost the same).

I will boil the glass bottles as well.

/ Marcus

 

[SpikeMacGee]

Hi all,
There seems to be some general confusion about the formulas, both the Classic and Cyanotype II can be found here:
Classic/Traditional formula:
http://www.alternativephotography.com/process_cyanotype.html
Cyanotype II process:
http://www.alternativephotography.com/process_cyanotype2.html

And i also agree, don't keep any chemicals in the fridge! Especially not if you have kids, i know what my kids are like, getting into everything!
Coffee filter or cheesecloth should do the trick of straning any mould.
ATB
Spike

 

[donbga]

I've heard thymol will also help prevent it. A couple drops of Listerine antiseptic mouthwash would probably do the trick...

Yea a few drops of 100% thymol solution in a liter of Part A works great. I've been using it for years. Thymol also works well to perserve gum acacia mixtures if you mix from powdered gum.

Unflavored Listerine could possibly work okay too.

 

[Photo Engineer]

Yea a few drops of 100% thymol solution in a liter of Part A works great. I've been using it for years. Thymol also works well to perserve gum acacia mixtures if you mix from powdered gum.

Unflavored Listerine could possibly work okay too.

Well, you can't make a 100% thymol solution, as thymol is a solid at room temperature.

I usually use 10% in alcohol, but listerine is just fine.

About 1 drop of the 10% / 100 ml of solution will be fine.

PE

 

[brummelisa]

I have to ask you with listerine do you mean like a mouth-wash?
Like this?
http://www.listerine.co.uk/

/ Marcus

 

[Photo Engineer]

I have to ask you with listerine do you mean like a mouth-wash?
Like this?
http://www.listerine.co.uk/

/ Marcus

Yes, sorry, in the US Listerine is a mouthwash that contains Thymol, Menthol and a few other ingredients that kill germs.

Thymol can be purchased from many chemical companies and druggists, and is pure enough to prevent contamination. Listerine has so many ingredients that contamination is possible.

PE

 

[donbga]

Well, you can't make a 100% thymol solution, as thymol is a solid at room temperature.

I usually use 10% in alcohol, but listerine is just fine.

About 1 drop of the 10% / 100 ml of solution will be fine.

PE

Well Ron you can make a 100% solution or close to it. 50 grams thymol dissolved in 50 ml 70% isopropyl alcohol. This solution was offered to me by Sam Wang, so if it's good enough for him it's good enough for me.

 

[Photo Engineer]

Don;

That is a 50% wt/vol solution. It is certainly ok, but very strong. It is by no means 100%.

PE

 

[donbga]

Don;

That is a 50% wt/vol solution. It is certainly ok, but very strong. It is by no means 100%.

PE

I knew you would say that, thanks for the clarification.
It is a strong sol. so a little goes a long way, but it certainly beats having mould (mold?) in Part A. Some people put Formalin in their gum mixture so I think the 50% thymol sol. is a better alternative.

 

[Photo Engineer]

I find that 10% thymol at 1 drop / 100 ml is good enough. More of it gives an odor to the materials that is strong, and also may cause tackiness.

PE