Two-bath Microphen?

[varjag]

Anyone here tried to come up with two-bath variation of Microphen formula? My understanding is that it is necessary to separate alkali into the second bath; however what should I do with bohric acid?

Also, how two bath version would behave in comparision to the original? Would it still be good old Microphen or should I expect entirely different characteristics?

 

[Tom Hoskinson]

Anyone here tried to come up with two-bath variation of Microphen formula? My understanding is that it is necessary to separate alkali into the second bath; however what should I do with bohric acid?

Also, how two bath version would behave in comparision to the original? Would it still be good old Microphen or should I expect entirely different characteristics?

You might try something like this:

A Solution

Water 750 ml
Sodium Sulfite20 g
Sodium Bisulfite 5 g
Hydroquinone 5 g
Phenidone 0.13 g
Potassium Bromide 1 g
Water to make 1000 ml

B Solution

Water 750 ml
Sodium Sulfite 85 g
Borax 7 g
Boric Acid 2 g
Water to make 1000 ml

Would it still be good old Microphen? NO! (this is actually a split version of ID-68 with some buffered sulfite in the A Bath)

I would try 3 minutes in A follwed by 3 minutes in B.

Good Luck!

 

[varjag]

Thank you Tom!

What is the role of Sodium Bisulfite in this recipe? I don't have it in my formulary handy; can it be substituted by anything?

 

[Tom Hoskinson]

The sodium bisulfite buffers the sodium sulfite and thus maintains the solution pH. At least, that's the theory. You can leave the sodium bisulfite out altogether - the developer will work without it.

 

[Gerald Koch]

You can't just separate the ingredients into a Bath A and the boric acid and borax into a Bath B. Bath B has to be rather alkaline whether from borax, sodium metaborate, or even sodium carbonate.

What I would do is to use Microphen as the A bath and use a B bath made of 10 g/l of sodium carbonate. If this produces too much contrast then use a B bath consisting of 10 to 20g/l of borax. You will need to do some experimenting.

OR you could just use Diafine.

 

[Tom Hoskinson]

Not just Borax and Boric Acid in the B bath.

Sodium Sulfite 85 g
Borax 7 g
Boric Acid 2 g

That should make a sufficiently alkaline B bath. If it isn't alkaline enough, add some more Borax - or Sodium Metaborate - or Sodium Carbonate.