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Keeping qualities of low-sulfite, metol-based film developers



 
 
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  #1  
Old April 20th 06, 04:05 AM posted to rec.photo.darkroom
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Default Keeping qualities of low-sulfite, metol-based film developers

Is a certain concentration of sodium sulfite critical to the keeping
qualities of developers that use metol as the only reducing agent? To
put the question in context, consider a hydroquinone-free variation on
DK-50:

metol 6g
sodium sulfite 30g
sodium metaborate 10g
postassium bromide 0.5g
water to make 1 liter

With the relatively low sulfite level of 3%, would such a developer be
less stable in storage (in full glass or nalgene bottles) than D76H or
D23, which call for 10% sodium sulfite? If so, what is the minimum
level of sulfite required for good keeping qualities?

  #2  
Old April 21st 06, 12:16 AM posted to rec.photo.darkroom
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Default Keeping qualities of low-sulfite, metol-based film developers

Brad Dow wrote:

Is a certain concentration of sodium sulfite critical to the keeping
qualities of developers that use metol as the only reducing agent? To
put the question in context, consider a hydroquinone-free variation on
DK-50:

metol 6g
sodium sulfite 30g
sodium metaborate 10g
postassium bromide 0.5g
water to make 1 liter

With the relatively low sulfite level of 3%, would such a developer be
less stable in storage (in full glass or nalgene bottles) than D76H or
D23, which call for 10% sodium sulfite? If so, what is the minimum
level of sulfite required for good keeping qualities?


I work with sulfited metol developers with and without
carbonate. In fact a few days ago I finished testing several
small bottles of year ago carbonated mixes. Nearly all
were at or near full strength.
I'd suggest you brew up that or a portion of the above
formula. Give it a few days in the bottles then test using
a one quarter portion of that used on a roll of film; perhaps
125ml at film strength. Test with a sheet of 5 x 7 paper.
Note the induction time. That is the time for first
appearance of an image. It is a measure of the developer's
activity. Test again at some latter times.
You may find it a good although slow print developer.
Add carbonate to speed it up. Results will be similar to
Ansco 120 even without the carbonate. Dan

  #3  
Old April 21st 06, 06:44 AM posted to rec.photo.darkroom
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Default Keeping qualities of low-sulfite, metol-based film developers

In article om,
"Brad Dow" writes:

Is a certain concentration of sodium sulfite critical to the keeping
qualities of developers that use metol as the only reducing agent? To
put the question in context, consider a hydroquinone-free variation on
DK-50:

metol 6g
sodium sulfite 30g
sodium metaborate 10g
postassium bromide 0.5g
water to make 1 liter

With the relatively low sulfite level of 3%, would such a developer be
less stable in storage (in full glass or nalgene bottles) than D76H or
D23, which call for 10% sodium sulfite? If so, what is the minimum
level of sulfite required for good keeping qualities?


I can't answer your question with respect to the developer you mention,
but Patrick Gainer has created some interesting NO-sulfite developers with
excellent keeping qualities. Most of Gainer's developers are
phenidone/ascorbic acid (PC) developers, though. Specifically, PC-Glycol
is made from phenidone and ascorbic acid in glycol with a separate
solution of carbonate. (The two are mixed together at time of use.) PC-TEA
consists of phenidone and ascorbic acid in triethanolamine (TEA), which
acts as both a solvent and an activator. Check
http://www.apug.org/forums/showthread.php?p=255352 for details.

IIRC, metol is soluble in propylene glycol but not in TEA. Thus, you might
be able to cross your DK-50 variant with PC-Glycol to get something
similar to DK-50 with excellent keeping qualities. I made my first batch
of PC-Glycol about a year ago and it's still going strong.

--
Rod Smith,
http://www.rodsbooks.com
Author of books on Linux, FreeBSD, and networking
  #4  
Old May 2nd 06, 06:13 AM posted to rec.photo.darkroom
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Default Keeping qualities of low-sulfite, metol-based film developers

Rod Smith wrote:

In article om,
"Brad Dow" writes:


Is a certain concentration of sodium sulfite critical to the keeping
qualities of developers that use metol as the only reducing agent? To
put the question in context, consider a hydroquinone-free variation on
DK-50:

metol 6g
sodium sulfite 30g
sodium metaborate 10g
postassium bromide 0.5g
water to make 1 liter

With the relatively low sulfite level of 3%, would such a developer be
less stable in storage (in full glass or nalgene bottles) than D76H or
D23, which call for 10% sodium sulfite? If so, what is the minimum
level of sulfite required for good keeping qualities?



I can't answer your question with respect to the developer you mention,
but Patrick Gainer has created some interesting NO-sulfite developers with
excellent keeping qualities. Most of Gainer's developers are
phenidone/ascorbic acid (PC) developers, though. Specifically, PC-Glycol
is made from phenidone and ascorbic acid in glycol with a separate
solution of carbonate. (The two are mixed together at time of use.) PC-TEA
consists of phenidone and ascorbic acid in triethanolamine (TEA), which
acts as both a solvent and an activator. Check
http://www.apug.org/forums/showthread.php?p=255352 for details.

IIRC, metol is soluble in propylene glycol but not in TEA. Thus, you might
be able to cross your DK-50 variant with PC-Glycol to get something
similar to DK-50 with excellent keeping qualities. I made my first batch
of PC-Glycol about a year ago and it's still going strong.



Metol is the hydrosulfate of 4(methyl-aminophenol) or some such thing.
The hydrosulfate is what makes it soluble in water. It is possible to
remove the hydrosulfate, which is sulfuric acid, and dissolve the Metol
base in TEA or glycol. This can lead to some interesting developers,
including a metol-ascorbic acid stock solution in either TEA or glycol.
It has more tanning ability than the phenidone version, which is
supposed to give it more sharpness due to the refraction of the gelatin
relief image. I'll dig up my notes and come back later with a recipe. It
doesn't require much heating: just enough to reduce the viscosity for
quicker mixing. Basically, the idea is to make a slurry with TEA, metol
and ascorbic acid, then add just enough water to make the TEA basic.
There may be a little precipitate of the sulfate, but it is possible to
make quite a concentrated stock in this manner.

  #5  
Old May 2nd 06, 05:44 PM posted to rec.photo.darkroom
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Default Keeping qualities of low-sulfite, metol-based film developers

PATRICK GAINER wrote:

Rod Smith wrote:

In article om,
"Brad Dow" writes:


Is a certain concentration of sodium sulfite critical to the keeping
qualities of developers that use metol as the only reducing agent? To
put the question in context, consider a hydroquinone-free variation on
DK-50:

metol 6g
sodium sulfite 30g
sodium metaborate 10g
postassium bromide 0.5g
water to make 1 liter

With the relatively low sulfite level of 3%, would such a developer be
less stable in storage (in full glass or nalgene bottles) than D76H or
D23, which call for 10% sodium sulfite? If so, what is the minimum
level of sulfite required for good keeping qualities?



I can't answer your question with respect to the developer you mention,
but Patrick Gainer has created some interesting NO-sulfite developers with
excellent keeping qualities. Most of Gainer's developers are
phenidone/ascorbic acid (PC) developers, though. Specifically, PC-Glycol
is made from phenidone and ascorbic acid in glycol with a separate
solution of carbonate. (The two are mixed together at time of use.) PC-TEA
consists of phenidone and ascorbic acid in triethanolamine (TEA), which
acts as both a solvent and an activator. Check
http://www.apug.org/forums/showthread.php?p=255352 for details.

IIRC, metol is soluble in propylene glycol but not in TEA. Thus, you might
be able to cross your DK-50 variant with PC-Glycol to get something
similar to DK-50 with excellent keeping qualities. I made my first batch
of PC-Glycol about a year ago and it's still going strong.



Metol is the hydrosulfate of 4(methyl-aminophenol) or some such thing.
The hydrosulfate is what makes it soluble in water. It is possible to
remove the hydrosulfate, which is sulfuric acid, and dissolve the
Metol base in TEA or glycol. This can lead to some interesting
developers, including a metol-ascorbic acid stock solution in either
TEA or glycol. It has more tanning ability than the phenidone version,
which is supposed to give it more sharpness due to the refraction of
the gelatin relief image. I'll dig up my notes and come back later
with a recipe. It doesn't require much heating: just enough to reduce
the viscosity for quicker mixing. Basically, the idea is to make a
slurry with TEA, metol and ascorbic acid, then add just enough water
to make the TEA basic. There may be a little precipitate of the
sulfate, but it is possible to make quite a concentrated stock in this
manner.


I'm back.

A solution of the metol base in glycol may be prepared as follows:

Take 10 grams of metol and 9 grams of TEA (about 8 ml at room temp.) and
make a paste. Add a teaspoon of hot water and
keep on stirring. At this point, decide whether you want to use
propylene glycol or TEA as the main solvent. I would suggest
glycol as being the more flexible. Add enough to bring the volume to 100
ml. You may treat this solution as if it were 10% metol.
You could use it to play with D-23 clones or whatever strikes your fancy.

To make 500 ml of a stock of MC-Glycol:

Take 5 grams of metol, 50 grams of ascorbic or erythorbic acid, and 85
ml of TEA and make a paste or slurry. Add 50 ml hot
water and stir. Add glycol to make 500 ml and stir. It will help to heat
while stirring, but temperature need not be any higher than
you can get with a water bath or double boiler. You must have another
stock of an alkali, or add some solid alkali to the
working solution. I have used the metaborate B solution of PMK. Look up
what others have been doing with PC-Glycol and try
the same.

 




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