[alt-photo] Re: On working with hydrochloric acid

[francis schanberger]

The dim room is just my work area with a darkroom sink in the basement of
my house.

I should just call it my "poorly lit room".

I do I five minute soak in each of two vinegar baths followed by a thorough
rinse in tap water. The first vinegar bath gets discarded after eight
sheets of 22" x 30" FAEW have gone through.

That's where I think the pH test strips would be useful (testing the first
vinegar bath).

The paper is hung on a clothes line until dry (usually overnight).

-Francis


On Sunday, February 17, 2013, etienne garbaux wrote:

> Francis wrote:
>
>  I've been re-acidifying FAEW hot press with distilled white vinegar.
>> I  haven't used (but am considering using) pH paper strips to
>> monitor the acidity since its hard to see any bubbles in solution
>> in my dim room.
>>
>
> Or, you could do it real old-school style -- dip your finger into the bath
> and touch it to your tongue.  Of course, DO NOT do this if you have reason
> to believe anything toxic may have been solubilized, for example, if the
> bath is a clearing bath after any dichromated or heavy metal process, or
> you have reason to believe the paper has anything significantly toxic in it.
>
> Since the paper needs to be at least washed, and probably substantially if
> not fully dried (or do you coat right out of the rinse with the paper fully
> wet, just squeegeed?), why do it in a dim room to begin with?  Please note
> that I'm not disparaging the use of real measurement tools -- I myself use
> a cheap portable pH meter for such things -- just asking.  And vinegar is
> weak enough that it doesn't effervesce very dramatically, anyway,
> particularly as the reaction nears completion, so you need to leave the
> paper in active vinegar for at least 2 or 3 if not 5 or 10 times as long as
> you see bubbles in any event.  (This is true even for more active acids at
> the relatively low concentrations we use in alt processing.)
>
> Best regards,
>
> etienne
>
>
>
>
>
>
>
>
> ______________________________**_________________
> Alt-photo-process-list | http://altphotolist.org/**listinfo<http://altphotolist.org/listinfo>
>


-- 
francis schanberger

www.francisschanberger.com