RA-4 without Triethanolamine

Rafael Saffirio · Jun 19, 2020

Hi.
Does anyone knows if a homemade RA-4 developer without Triethanolamine could work? Or if can be replaced by something that comes in powder ?

koraks · Jun 20, 2020

I suspect it'll work if you use a different buffer and adjust pH over the working lifetime of the developer so that it remains fairly constant. The nice thing about TEA is that it's a pretty reliable buffer; I suspect that's really the only reason it's used in this application.

Rudeofus · Jun 20, 2020

TEA does several different things: it's an alkali, a buffer, and silver solvent, a sequestering agent for certain trace metals. Apart from that, I have read, that RA-4 printing paper is about the most cost optimized product in the world of photography, and that pretty bizarre tricks are pulled to minimize its required silver content. This could mean, that typical RA-4 paper simply expects TEA to be present for reasons nobody here can explain, but valid nevertheless. You can try to replace the TEA with a suitable alkali and some solvent (not sulfite! ), but it may still give you strange and inexplicable results.

Rafael Saffirio · Jun 20, 2020

Well I guess there is a reason why nobody as come up with a powder RA-4 Dev like the C-41 unicolor , I wanted to mix small quantities to make 500ml or even less and put it in zip lock bags (I do that with D76) and have then ready for when I need them.

mohmad khatab · Jul 8, 2020

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grainyvision · Jul 16, 2020

In theory you could freeze the TEA and keep the powder refrigerated to ensure the TEA remains a "powder". Not really very convenient though. Probably the easiest solution is keeping a small measured bottle of the TEA with the powder and rinsing the bottle a few times to ensure you get all of the TEA out of it

AgX · Jul 16, 2020

Rafael Saffirio said:
Well I guess there is a reason why nobody as come up with a powder RA-4 Dev.

Not powder but granules or tablets were/are on the market.

Rafael Saffirio · Jul 21, 2020

AgX said:
Not powder but granules or tablets

of Ra-4 or TEA??

AgX · Jul 22, 2020

Granules or powder of RA-4.

RA-4 without Triethanolamine

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