• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Pyrocat HD - Sodium carbonate instead of Potassium carbonate?

Recent Classifieds

Forum statistics

Threads
201,976
Messages
2,833,147
Members
101,041
Latest member
Geo58
Recent bookmarks
0

Baxter Bradford

Member
Allowing Ads
Joined
Nov 17, 2004
Messages
795
Location
Lymington, S
Format
4x5 Format
When ordering chemicals for my first attempt with Pyrocat, the chap from Retrophotographic didn't stock Potassium Carbonate and persuaded me that I could use Sodium Carbonate instead. Any advice on how this might affect development/film speed kindly appreciated.

I see from unblinkingeye an addendum that:
"Mr. King has modified solution B to use a 100% solution of potassium carbonate instead of a 10% solution of sodium carbonate. An earlier version of the formula published on the rec.photo newsgroup called for 2.5 grams of metol in place of the phenidone. Mr. King suggests that this formulation may be more stable than the phenidone version. The keeping time for solution A when formulated with phenidone is about 3-6 months. Ted Kaufman has recommended substituting a 10% solution of sodium hydroxide for solution B."

There is no more explanation than that, not we have become accustomed to on APUG!

I want to keep things as simple as possible, having no desire whatsoever to reinvent wheels, just to reap the rewards of others' hard work. I do now have a digital pH meter if this is any help in adjusting dilutions etc to keep things as close to the mainstream as possible.
 

John Z.

Member
Allowing Ads
Joined
Dec 5, 2004
Messages
64
Format
ULarge Format
I use the metol listed in the article instead of the phenidone--easier to work with in my opinion. I also use the sodium carbonate. When I have tried the Potassium carbonate on a few occassions the negatives seemed softer--lower contrast overall. Anyone else noticed this?
 

Donald Miller

Member
Allowing Ads
Joined
Dec 21, 2002
Messages
6,230
Format
Large Format
I use sodium carbonate as well. When using sodium carbonate, the amount of water used must be increased five fold because saturation on NaCO3 is much lower then KCO3...
 

Ole

Moderator
Subscriber
Allowing Ads
Joined
Sep 9, 2002
Messages
9,245
Location
Bergen, Norway
Format
Large Format
I get around the whole "B" sodium/potassium carbonate solubility problem by not making a "B" at all. Instead I dissolve the necessary amount of carbonate for the final soup in the water, then add "A". One less bottle to keep around.
 
OP
OP
Baxter Bradford

Baxter Bradford

Member
Allowing Ads
Joined
Nov 17, 2004
Messages
795
Location
Lymington, S
Format
4x5 Format
Thanks for the info. Am looking forward to getting going on this. Seems I was panicking too quickly.

Ole, I am intending to use your Quick Fix - OF1 so thanks for the help on this too.
 
Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links.
To read our full affiliate disclosure statement please click Here.

PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Ilford ADOX Freestyle Photographic Stearman Press Weldon Color Lab Blue Moon Camera & Machine
Top Bottom