Herbst WD2D Excessive Stain

[Steve Hamley]

Folks,

I've been trying out WD2D as Bob Herbst lists here under "writings":

http://www.bobherbst.com/

The developer seems to work as advertised except that I'm getting excessive stain that's clearly overdone in the border areas of my negatives where there is no exposure. The borders are extremely green. I've also noticed that it leaves a pronounced "bathtub ring" around the developer tray which I assume is from developer that's more oxidized than it should be.

I developed a duplicate negative (same film stock), same subject, etc, in PMK and got a very clear negative margin with a nice stain, so I'm certain it isn't film. Also, it doesn't look like fog - just stain.

Other details, the darkroom is cool, 65-68 degrees, tray developing, 1:1:10 dilution (as specified), agitation 10 seconds every 30 seconds, and other than the excessive stain, the negatives look fine.

Cheers, and thanks,

Steve

 

[pgomena]

WD2D or WD2D+? The tech sheet for WD2D+ from Photographer's Formulary says to dilute 1:1:50 with distilled water. I've never had excessive staining from WD2D+.

Peter Gomena

 

[Steve Hamley]

Peter,

Thanks for the reply; WD2D - not WD2D+ - mixed in distilled water.

Cheers, Steve

WD2D or WD2D+? The tech sheet for WD2D+ from Photographer's Formulary says to dilute 1:1:50 with distilled water. I've never had excessive staining from WD2D+.

Peter Gomena

 

[Lee L]

Bob has an APUG account, but doesn't come around much anymore. I'm sure he'd give you a response if you email him at the contact address on his web site.

 

[bobherbst]

Herbst WD2D Excessive Stain - Wrong formula?

Hi Lee. How are you. Email me. Been gone a long time. Politics.

Steve, if your stain is green you're not using the same formula as original Wimberley, my modified Wimberley, or WD2D+. Green stain comes from use of sodium metaborate (Kodalk) as the alkalai in the developer formula. PMK and Rollo use metaborate. Wimberley, ABC, and other formulas which use sodium carbonate as the alkalai in the developer produce a stain which is yellowish-brown. If your stain is green you're not using the same formula.

Folks,

I've been trying out WD2D as Bob Herbst lists here under "writings":

http://www.bobherbst.com/

The developer seems to work as advertised except that I'm getting excessive stain that's clearly overdone in the border areas of my negatives where there is no exposure. The borders are extremely green. I've also noticed that it leaves a pronounced "bathtub ring" around the developer tray which I assume is from developer that's more oxidized than it should be.

I developed a duplicate negative (same film stock), same subject, etc, in PMK and got a very clear negative margin with a nice stain, so I'm certain it isn't film. Also, it doesn't look like fog - just stain.

Other details, the darkroom is cool, 65-68 degrees, tray developing, 1:1:10 dilution (as specified), agitation 10 seconds every 30 seconds, and other than the excessive stain, the negatives look fine.

Cheers, and thanks,

Steve

 

[Steve Hamley]

Hi Bob,

Thanks for the reply. I believe part of the problem might be the use of Arm and Hammer Super Washing Soda as the alkali, which I suspect "Super" means it has something besides sodium carbonate in it. As a test, I tried Wimberly WD2H with 0.9X photo grade potassium carbonate and I got a very clean negative with a very clear base and not even a trace of a "bathtub ring". I just did a two-neg test, so I'm going to test a bit more. The base stain was essentially the same color as PMK.

Cheers, Steve

 

[Kirk Keyes]

Arm and Hammer Super Washing Soda is pretty much just sodium carbonate:
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3005006

 

[Steve Hamley]

Thanks Kirk,

I posted mainly to see what experience others had with it, and that the photo grade potassium carbonate seemed to do better in a VERY limited one-neg test. I think the next step is to remix my washing soda solution verifying quantities (and I always mix in distilled water) and do some more testing.

I'm also curious if the stain color varies between sodium carbonate and potassium carbonate.

Cheers, Steve

 

[Photo Engineer]

You might want to record the pH of the various mixes you are making up. We do not really know the purity of the Arm and Hammer Washing Soda, nor do we know what the impurities are.

PE

 

[nworth]

You might want to record the pH of the various mixes you are making up. We do not really know the purity of the Arm and Hammer Washing Soda, nor do we know what the impurities are.

PE

Borax was sometimes used as a booster in washing soda. It doesn't take much to noticeably enhance the detergent effect. Maybe that is what is happening here. Anyone know a quick test for borate?

 

[Photo Engineer]

I believe that there is one. But, it is forgotten since analytical chemistry days.

PE

 

[jkschreiber]

I learned the hard way that there is at least one situation where a green stain can be produced with (but not by) the Wimberley formula or (I suspect) any of its variants, or ABC etc.

A few years ago I had to develop a fairly large quantity of 7x17 BPF in a borrowed darkroom, not in my hometown, and in a very limited time. I was using Bob's variation of the Wimberley WD2D formula since I too make my negs to be printed in Pt/Pd. I had also visited Bob earlier that summer and was very impressed with the results he was obtaining. I had forgotten to bring the TF-4 fixer that I usually use, so I just used what was on hand. Much to my surprise, the negs had a green stain just like you would expect from PMK, but I was using WD2D. I was later able to determine that the fixer I was using, Sprint Record Speed Fixer, contains Sodium Metaborate as a minor ingredient.

The moral of the story is that Sodium Metaborate will produce a green stain with pyro developers even if it is present not in the developer itself, but in the fixer. Fortunately, this is a rare thing, but still something to be aware of.

As it turned out, this was only a minor annoyance, since a much bigger problem was that most of the film I used on this project turned out to be from a batch that had coating flaws which rendered much of it unusable.

~ Keith

Steve, if your stain is green you're not using the same formula as original Wimberley, my modified Wimberley, or WD2D+. Green stain comes from use of sodium metaborate (Kodalk) as the alkalai in the developer formula. PMK and Rollo use metaborate. Wimberley, ABC, and other formulas which use sodium carbonate as the alkalai in the developer produce a stain which is yellowish-brown. If your stain is green you're not using the same formula.