85% TEA - Do I have to adjust quantities?

[fdonadio]

Hello, guys and gals!


I've searched the forums before posting, but it isn't exactly clear for me yet.

I have access to 85% TEA (Triethanolamine) in my area. It's mostly TEA with 15% DEA (Diethanolamine). The "pure" stuff (99%?) is nowhere to be seen.

@Photo Engineer says he uses Photographers Formulary TEA and that it is 85% — just like the one I have access to — and, most importantly, that it works. He advises, though, that the DEA will result in higher pH and, therefore, higher developer activity.

Now the question is: I have seen many formulas here — for both B&W and color film and paper — that use TEA, but they don't specify the concentration. I assume they call for pure TEA. If I'm using 85% TEA, should I adjust the quantity?

I understand that, if the formula specifies the pH of the final product, I can use a diluted acid to bring the pH down to it and that this is pretty much standard practice.


Cheers,
Flavio

 

[Gerald C Koch]

Tough question. Some formulas assume pure TEA while others expect the mixed TEA+DEA. The obvious answer is to use the same kind as the formula calls for. If you have an MSDS then it should start the exact composition. If one is not specified then one has to guess. While the mixed TEA+DEA does have a higher pH I would just use a one for one substitution. I use pure TEA from the chemistrystore.com which comes with an MSDS stating that it is 99+% TEA..

To make things even more complicated each of the two mentioned forms is also available with 15% water added. Only in these last two cases would one have to make an adjustment in the quantity used.

 

[fdonadio]

While the mixed TEA+DEA does have a higher pH I would just use a one for one substitution.

That's what I wanted to know. I guess the difference is minimal...

Thanks, Gerald!

 

[Photo Engineer]

I agree!

PE

 

[Alan Johnson]

Sandy King measured the pH of PC-TEA in this thread if that is what you are mixing:
https://www.photo.net/discuss/threads/greater-dilutions-of-pc-tea-any-thoughts.125765/

 

[sfaber17]

I never got anything to work with that 85% stuff.

 

[fdonadio]

Sandy King measured the pH of PC-TEA in this thread if that is what you are mixing:
https://www.photo.net/discuss/threads/greater-dilutions-of-pc-tea-any-thoughts.125765/

In fact, I considered mixing PC-TEA, but I am more interested in trying PE's RA4 formulas.

Thanks for the heads up!

 

[Photo Engineer]

I think that the RA4 formulas are from a patent, they are not "mine", just a reference. Best of luck with them and let us know what you think.

PE

 

[fdonadio]

I think that the RA4 formulas are from a patent, they are not "mine", just a reference. Best of luck with them and let us know what you think.

I wasn't exactly clear. I meant "your formula" as "the formula you posted".

Blankophor REU is now the last remaining hard to find component.

 

[Photo Engineer]

Leave it out..

It is just an optical brightener.

PE

 

[fdonadio]

All right... I am gonna try it without the brightener, then.

Thanks, Ron!