In the UK silverprint at www.silverprint.co.uk list
500g for about 7 UK pounds and they recommend 20g per
litre for use. An excellant website and catalogue
well worth a browse for home printers.
--- "Peifer, William [OCDUS]" <[EMAIL PROTECTED]>
wrote:
> Roger the former chemist wrote:
> >As a former chemist, let me offer a few suggestions
> to those
> >using glacial acetic acid:
> [Excellent rules for home use of CH3COOH
> snipped....]
>
>
> Bill the presently-employed-as-chemist humbly
> inquires:
>
> Has any home darkroom enthusiast on the list ever
> used -- or ever read about
> the use of -- citric acid rather than acetic acid as
> a stop bath? I was
> just curious about this. Citric acid is certainly a
> lot safer to store at
> home that glacial acetic acid, it's convenient in
> that it's a powder rather
> than a liquid, it doesn't smell as bad, it's already
> used in a lot of
> consumer products, and it's pretty cheap. A large
> US laboratory chemicals
> supplier lists glacial acetic acid at $130 USD for
> 12 kg (packaged in four
> 3-kg glass jugs), and citric acid monohydrate at $64
> USD for 5 kg (in a
> plastic container). It's true that on a
> per-molecule basis it's about four
> times as expensive as acetic acid, but it also has
> three times the acid
> strength (three acidic groups per molecule to acetic
> acid's one per
> molecule). That third acidic proton (the last one
> to be stripped off when
> citric acid reacts with alkaline material) provides
> good buffering up to
> about pH 7.4, which should be low enough to
> neutralize residual developer.
>
> Probably not an economical alternative for the
> commercial lab, unless you
> calculate in the cost of engineering controls,
> personal protective
> equipment, environmental compliance, etc.
>
> Just wonderin'.... Perhaps as an OT, someone on the
> list is going to have
> to address the use of a nice dry sauvignon blanc as
> a stop bath, and a
> full-bodied young cabernet as developer. Now
> there's a darkroom we can
> really enjoy! :-)
>
> Bill Peifer
> Rochester, NY
>
> -
> This message is from the Pentax-Discuss Mail List.
> To unsubscribe,
> go to http://www.pdml.net and follow the directions.
> Don't forget to
> visit the Pentax Users' Gallery at
> http://pug.komkon.org.
>
=====
Regards
Richard Saunders
__________________________________________________
Do You Yahoo!?
Yahoo! Auctions - Buy the things you want at great prices.
http://auctions.yahoo.com/
-
This message is from the Pentax-Discuss Mail List. To unsubscribe,
go to http://www.pdml.net and follow the directions. Don't forget to
visit the Pentax Users' Gallery at http://pug.komkon.org.
