Sodium Thiosufate Fixer With FB Papers

Vlad Soare · Nov 3, 2010

Hello,

I have a couple of questions for those of you who use home-brewed sodium thiosulfate fixers with FB papers. How long do you fix? How do you determine the correct fixing time?
Also, how you know when a batch of fixer is exhausted from an archival point of view? The fact that it still clears a piece of film is no guarantee that it's still safe to fix FB papers to archival standards.

Thank you.

Muihlinn · Nov 3, 2010

I'd start with no less than 5 minutes and 20 prints per liter.
I'll run tests with ST-1 formula to determine if it's well fixed if I wanted to be sure.

archer · Nov 3, 2010

If using an alkaline or neutral sodium thiosulphate based fixer, the fix rate for double weight fiber base paper to archival standards is a two tray fix regimen of 5min in each of fix 1 and fix 2 for a total of 10 min. After 20 8x10 prints per liter have been fixed, fix 2 replaces fix 1 which is then discarded and a new fix 2 is mixed and the sequence is repeated. The reason I specified an alkaline or neutral fix is because complete archival washing is much more efficient with acid free fixer, given the same wash times. The capacity of the fixer given above is conservative but for absolute safety, I would not skimp on such an inexpensive and important part of the process.
Denise Libby

Gerald C Koch · Nov 3, 2010

Kodak always recommended 5 to 10 minutes for their sodium thiosulfate based fixers.

Vlad Soare · Nov 4, 2010

Thank you.
I'll go for five minutes in each bath, then.

c6h6o3 · Nov 4, 2010

50 grams/liter of sodium bisulfite in the first fix of a two solution regimen will keep it from turning yellow.

photo8x10 · Nov 4, 2010

As first fixer I usually use Kodak F-24 and my second fixer is a simple bath of sodium thiosulphate.
For both baths my time is 4 minutes.

Stefano

Vlad Soare · Nov 4, 2010

I use sodium sulfite as a preserver because I like to keep the solution basic, mostly for smell reasons. Fixer starts to stink when it gets too acidic. Besides, right now I only have a limited supply of bisulfite, which I'm saving for ABC Pyro.

sodium thiosulfate 160g anhydrous or 250g pentahydrate
sodium sulfite 30g (preserver)
sodium bicarbonate 1 tbs. (buffer, to keep the pH from getting too low because of stop bath carryover)
water to make 1l

I've been using this formula with films for some time and liked it. It's totally odorless and clears normal films in two minutes and T-Max in four. I'd like to start using it with papers, too.

Anon Ymous · Nov 4, 2010

Vlad, why not add some ammonium chloride? This will speed things up.

Vlad Soare · Nov 5, 2010

I know, but speed is not an issue for me, so I'd rather not add an extra component. I like to keep things simple. Besides, I think an ammonium compound would be a new source of smell.

Wade D · Nov 5, 2010

5 minutes will work fine. No need to over complicate it.

c6h6o3 · Nov 5, 2010

VladSoare said:
I know, but speed is not an issue for me, so I'd rather not add an extra component. I like to keep things simple. Besides, I think an ammonium compound would be a new source of smell.

It also turns the prints pink with certain paper / developer combos. (such as Azo or Lodima in amidol)

Vlad Soare · Nov 6, 2010

Indeed, I did notice that Lodima in amidol looked a bit pinkish, but I thought it was either the quality of my amidol, or something I was doing wrong.
OK then, no more rapid fixers from now on, at least not with Lodima.

FotoGys · Nov 7, 2010

c6h6o3 said:
50 grams/liter of sodium bisulfite in the first fix of a two solution regimen will keep it from turning yellow.

Keeping the fix from turning yellow or keeping the fb print from turning yellow?

Guus

c6h6o3 · Nov 7, 2010

FotoGys said:
Keeping the fix from turning yellow or keeping the fb print from turning yellow?

Guus

The fixer. With any developer except Chinese amidol. That stuff turns all other solutions a bright orange and I just one shot everything.

Gerald C Koch · Nov 11, 2010

Vlad Soare said:
I know, but speed is not an issue for me, so I'd rather not add an extra component. I like to keep things simple. Besides, I think an ammonium compound would be a new source of smell.

Ammonium chloride will not produce any smell (ammonia gas) unless the fixer becomes very alkaline.

Vlad Soare · Dec 8, 2010

Could I make the second fix in one single step? I mean, all prints at once?
I'm thinking of fixing each print for five minutes in the first bath, then letting all of them accumulate in a tray of water. At the end of the session, I'd move them all to the tray with the second fixer, and keep them there for five minutes with constant interleaving (like I do with films developed in trays - remove the bottom print and move it to the top).
I think this should work as well as if I fixed each sheet individually for five minutes. Is there any reason why it shouldn't?

archer · Dec 8, 2010

Dear Vlad;
That will work just fine. Just remember to keep the total fixing time at ten minutes.
Denise Libby

Doremus Scudder · Dec 8, 2010

Vlad,

Waiting for your second fixing bath is fine. In my workflow, I fix in bath one, wash and dry the prints. I then cull the prints that don't meet muster and tone the rest later in larger batches (soak, fix, tone, hca, wash). The second fix comes before the toning, usually several days after the first fix. Never a problem and excellent residual hypo and silver tests. I actually think that the first wash helps a lot.

If you are processing for maximum permanence, two-bath fixing is the only way to go. Read up on capacities and determine what your throughput should be. Then test for residual silver to determine if your last prints are really fixed properly. Different papers can have different capacities, so take that into account. I err on the side of caution and usually underuse my fix; it's a lot cheaper than paper.

Best,

Doremus Scudder
www.DoremusScudder.com

Sodium Thiosufate Fixer With FB Papers

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