What is KOH?

I have an Ektaflex printer and donor and receiver paper. I don't expect it to result in something great at this point, but I would like to experiment. I thought of coating a piece of watercolor paper with cyanotype and running it as the receiver paper against the donor, and thinking I might get some cool, weird colors on the cyanotype to expose then.

I dont have any activator. I saw in another post that KOH was used as the activator. What is KOH? and does anyone else have a recipe?

Thanks

Sorry to sound so harsh, but if you have so little knowledge of chemistry to not know the chemical formula, please don't mess with the stuff. It's far from harmless.

I'm not familiar with the Ektaflex system. I do know that if you apply an alkaline solution to a cyanotype, it'll bleach. Applying even a weak solution of potassium hydroxide to a cyanotype will virtually instantly bleach it to a near-invisible state.

grain elevator said:

Sorry to sound so harsh, but if you have so little knowledge of chemistry to not know the chemical formula, please don't mess with the stuff. It's far from harmless.

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There are risks involved, yes. If @scott laursen is planning to work with potassium hydroxide, he'd have to inform himself of these risks and safe handling procedures. I don't agree he necessarily should disregard the option - we all have to start somewhere. But it's definitely not the safest material to start darkroom chemistry work with.

More importantly I doubt whether it's necessary or even the best choice to mess with KOH in this application.

grain elevator said:

Sorry to sound so harsh, but if you have so little knowledge of chemistry to not know the chemical formula, please don't mess with the stuff. It's far from harmless.

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I would give OP the benefit of doubt. Depending on the context where OP saw "KOH", it might not have been obvious that it was a chemical formula, and not, for example, an acronym for a product. I can easily imagine someone having a perfectly good and strong chemistry background, and still not make that particular connection. "KOH" *looks* like it could be a acronym.

scott laursen said:

I have an Ektaflex printer and donor and receiver paper. I don't expect it to result in something great at this point, but I would like to experiment. I thought of coating a piece of watercolor paper with cyanotype and running it as the receiver paper against the donor, and thinking I might get some cool, weird colors on the cyanotype to expose then.

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Why don't you start with plain cyanotype chemistry? You can buy an easy-to-use kit on Amazon and you "develop" cyanotype with just water. Cyanotype can be a lot of fun, and if you can make 8x10 negatives (I see that you shoot 8x10) you could get some really cool results.

dcy said:

"KOH" *looks* like it could be a acronym.

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I personally have come across the combination of "KOH" in two different meanings: as the chemical notation for potassium hydroxide, and as the first part of one of the many Thai islands (cf. Koh Samui), in which case only the K is capitalized. I don't doubt 'KOH' occurs in other meanings or contexts, but I think the ones I mentioned are the most common - and the chemical interpretation is a rather likely one in this specific context especially since it's referred to as an 'activator'.

dcy said:

Why don't you start with plain cyanotype chemistry?

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I have a feeling he already is quite familiar with making cyanotypes. The question is how he wants to combine it with this Ektaflex concept. Perhaps he should explain that a little more so we can comment more sensibly.

I wonder if perhaps @scott laursen has used the Ektaflex materials in the past, back when he still had the KOH activator at hand. https://www.photrio.com/forum/threa...-is-there-an-alternative.125172/#post-2011152

The Ektaflex "developer" (activator) is actually a solution of KOH, Potassium Hydroxide, and as I recall it was at a fairly high concentration with the usual warnings about goggles, etc. Potassium hydroxide is also knows as Caustic Potash (old nomenclature). It is every bit as caustic and corrosive as lye aka drain cleaner. Other threads on here have more info. I only used it a couple of times and was very impressed with the print quality but it was expensive to use.

dcy said:

I would give OP the benefit of doubt. Depending on the context where OP saw "KOH", it might not have been obvious that it was a chemical formula, and not, for example, an acronym for a product.

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Agree, it took me the longest time to figure out that TEA here isn't meaning Camellia sinensis.

Craig said:

Agree, it took me the longest time to figure out that TEA here isn't meaning Camellia sinensis.

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As TEA is not a chemical formula and thus a international and interdisciplinary standard nomenclature but a convenient acronym, that's more of an if you know, you know sort of deal. But yes, it can be used safely, if one knows what's they're doing, and that's not beyond what an amateur can learn. If they take it somewhat seriously.

When I first saw the KOH in the thread title, I mistook it for this ....

I thought of Jimmy Koh, the Rolleiflex guy in NY.

Ian C said:

Potassium hydroxide - Wikipedia

en.wikipedia.org

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Nailed it!