Home made D76 too much film base fog

[rui_alves_da_silva]

Hello Photo.net forum,

 

I recently have made a liter of D76 with 750ml of water @ 52C? 2gr

of metol, 100 gr of sodium sulfite, 5gr of hidroquinone and 2gr of

borax. And I get too much film base fog, like 0.44. Any gracious

hand to help me?

Regards,

Rui Alves da Silva

[rui_alves_da_silva]

Sorry, forget to say what film used.

Tri-x EI 200 for 8 minutes @ 19C? souped in this sh****** that I had made at home

[john_shriver]

Was your last step adding water to make one liter?

 

Was your sodium sulphite dessicated (anhydrous)?

 

You certainly have all the weights and volumes right.

 

Perhaps you mixed it so vigorously that you got a lot of oxygen into it. D-76 is prone to getting over active.

[lowell_huff1]

No restrainers in that formula. Little wonder "high base fog."

Use some Potassium Bromide. It controls "toe" fog.

[skygzr]

I've never needed a restainer with D76.....is it possible that your film is old?

[rowland_mowrey]

The D76 formula, as published, does not contain any restrainer.

 

The only error I see in that formula is not diluting to 1 liter, thereby making the soluton 25% more concentrated than required. Did you dilute the final mix to 1 liter? If not, that may be the problem.

 

You also must specify whether you used anhydrous (dessicated) or hydrated sodium sulfite.

 

Ron Mowrey

[stefan_kahlert2]

The formula is well known but your fog level sounds like the resulting pH is too high. Are you sure you got everything right? It's easy to make mistakes when mixing a formula for the first time. I'd think over everything I did and compare it to the corresponding instructions step by step and compound to compound. Then I'd check my raw chemicals (as far as possible) and carefully try it again.

 

Best

 

Stefan

[rui_alves_da_silva]

Hello again,

 

The sodium sulfite is anhydrous. The problem migth be from borax, I just bought another type of borax, previously I used in dust form, Today I bought one that is in granulous state. It can be the problem?

Otherwise, everything is done correctly. Very carefuly weight

[stefan_kahlert2]

The formula quoted looks right but your fog level sounds like the resulting pH is too high. Are you sure you got everything right? It's easy to make mistakes when mixing a formula for the first time. Think over everything you did and compare it to the corresponding instructions step by step and compound to compound. Then check the raw chemicals by eye and label and carefully try it again.

 

Best

 

Stefan

[rui_alves_da_silva]

Just prepared another liter. Carefuly prepared. Another curiosity is that the all film is very underdeveloped (time used is normal time for kodak d76), however I measured again film base, and hard to believe, 0.44 ...

 

Thanks for everyone, tomorow i'll have some news.

Rui

[rui_alves_da_silva]

Hello,

Tested with new liter and work perfectly. What I have done diferently? Just changed borax to a granulous version, previously used a powder version. And mixed slowly that first attempt when i have mixed vigorously.

Film base is between 0.29 and 0.33

 

If anyone want to use this soup, tri-x EI 200 35mm in d76 1:1 for 8 min for a fine grain and sharp images with full gradation. This time is like more a zone N-1 than N but I use split print and control contrast also with paper developer and toning.

 

Regards, Rui

[rui_alves_da_silva]

All at 19 degree celsius

[rui_alves_da_silva]

0.29 and 0.30 not 0.33

[patrick_gainer]

Let your mixture sit a while. Unbuffered D-76 tends to be more active when fresh. E.I. 200 is slow for Tri-X in D-76 by my experience. That would not account for high edge fog.

 

A later formula uses a combination of borax and boric acid to stabilize the pH. Don't remember the numbers, but you can find it in a book somewhere. The Darkroom Cookbook has it, I think.

[keith_tapscott]

Diluting the developer 1:1 helps. Alternatively, try the Adox MQ developer instead.

[hjoseph7]

"Hello, Tested with new liter and work perfectly. What I have done diferently? Just changed borax to a granulous version, previously used a powder version. And mixed slowly that first attempt when i have mixed vigorously. Film base is between 0.29 and 0.33"

 

 

Thanks Rui you just made my day. I recently purchased a X-Rite 810 densitometer and I kept getting consitent readings for Base+fog of 0.29-0.30. The 0.30 was due to not enough washing time for the film or not using hypo clearing agent. I thought I might be doing something wrong or that the Densitometer had to be recalibrated because allot of materials I have been reading so far indicated that base+Fog should be in the 0.10 - 0.15 range. Thanks allot !