Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > General discussions > Photography in general

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10th September 2020, 07:50 AM
JackBlack JackBlack is offline
New User
 
Join Date: Sep 2020
Posts: 2
Default Contamination of graduates

Hello! I often read about contamination. I would like to know if it's necessary to keep separate graduates for various chemicals or whether a good soap washing will decontaminate a graduate? I think in the case of trays such cleansing cannot be assured due to the clear instructions to keep 3 different trays.
Reply With Quote
  #2  
Old 10th September 2020, 08:58 PM
Bob's Avatar
Bob Bob is offline
Administrator
 
Join Date: Aug 2008
Location: London(ish)
Posts: 2,746
Default

I do keep separate measuring vessels for each of dev, stop and fix, but as the chemicals do not spend much time in there (and especially if you use glass) I don't see that it is 100% necessary. I have accumulated an assortment over the years and I guess having separate ones means you do not have to stop and washup in the middle of preparing working solutions.

Certainly you may want to keep developer utensils separate but no reason other than the extra faff not to use a single stop and fixer graduate. Colour has more chemical stages so may have different requirements but I don't do colour so can't suggest anything...
Reply With Quote
  #3  
Old 10th September 2020, 09:52 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Contamination

Most of the normal developing chemicals can be neutralised by filling them with something like Milton at 50% solution and leaving it for around 24 hours and rinsing out.

Hard plastics like ordinary clear Paterson measuring beakers are not so prone as vessels made from polypropylene. I measure my RA4 and C41 chemicals in Paterson beakers and only need just to rinse them out afterwards and so far have had no detrimental effect.

As Bob has said glass measuring beakers and storage jars need only a rinse out with plain water.
Reply With Quote
  #4  
Old 11th September 2020, 07:00 AM
Richard Gould Richard Gould is offline
Friend
 
Join Date: Dec 2008
Location: Jersey Channel Islands
Posts: 5,433
Default

I have a couple of the Paterson cylinders, and use them for blackj and white, and just rinse them out with plain water between chemicals, seems to work fine
Richard
Reply With Quote
  #5  
Old 11th September 2020, 07:45 AM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Contamination

The main source of contamination applies when you are dealing with RA4, C41 and principally E6 colour chemicals. It is a long time since I have used E6 and in the last Tetenal E6 processing kit there was a written warning about using the same measuring beakers for the 1st developer, bleach and 2nd developer as there is a possibility of a 'carry over.'

When mixing the developer for RA4 and C41 if you rinse out the mixing beaker that has held one of the chemicals the first 3 or 4 rinses will be tinged slightly pink. This will carry over if not completely eliminated.
Reply With Quote
  #6  
Old 11th September 2020, 08:09 AM
Lostlabours Lostlabours is offline
Friend
 
Join Date: Apr 2012
Location: West Midlands/Aegean
Posts: 1,988
Default

Some do, I don't and never have as I use my measures in sequence and keep most chemicals like stop bath and fixer pre-mixed in bottles and pour straight from them into tanks or trays. Actually when I used replenished developer it was the same.

A good wash and re-use for anything. Never had an issue in 50+ years of B&W and Colour processing.

Ian
Reply With Quote
  #7  
Old 11th September 2020, 11:51 AM
Terry S Terry S is offline
Friend
 
Join Date: Dec 2011
Location: Southend on Sea, Essex, England, UK
Posts: 3,795
Default

Over all of the decades that I have done film and print developing, I have never even thought about this subject - of using a separate graduates for individual chemicals, which for me is three, as I only do b/w.

I do use the same graduate when measuring out all three chemicals and just give it a good rinse between each of them. Over all the decades that I have done this, I have never had a problem but the chemicals are not in the graduate for very long, usually minutes at most.

As for bottles for long term storage of liquids, I use a different labelled bottle for each and rinse them out well when a bottle is emptied and before refilling it again with a similar liquid.

But be careful with your labeling and don't take one off before refilling with a similar liquid and writing a new label out. I took the label off of a bottle fix quite recently (see my post 'Is my metol dead') and accidentally refilled the bottle with developer, which then died on me by the time I went to develop my second film. So be warned, mistakes can and do happen.

Terry S
Reply With Quote
  #8  
Old 11th September 2020, 06:26 PM
JOReynolds JOReynolds is offline
Friend
 
Join Date: Nov 2012
Location: St Albans UK/Agde France
Posts: 1,074
Default graduate materials

Quote:
Originally Posted by John King View Post
Hard plastics like ordinary clear Paterson measuring beakers are not so prone as vessels made from polypropylene.
I note that some scientific and medical laboratories handling chemicals still use glass graduates but in general glass is regarded as hazardous and they substitute PP (polypropylene), virtually unbreakable, POM (polyoxymethylene) and PMP (polymethylpentene), both tough and resistant to high temperature. Some photographic chemicals stain PP, POM and PMP but this takes some time. Graduates used for proportioning concentrates are unlikely to be in contact with nasties for more than a few minutes, so all are quite safe. Paterson graduates are moulded of PS (polystyrene).
Reply With Quote
  #9  
Old 11th September 2020, 09:49 PM
John King John King is offline
Friend
 
Join Date: Nov 2012
Location: County Durham
Posts: 3,318
Default Glass graduates

Quote:
Originally Posted by JOReynolds View Post
I note that some scientific and medical laboratories handling chemicals still use glass graduates but in general glass is regarded as hazardous and they substitute PP (polypropylene), virtually unbreakable, POM (polyoxymethylene) and PMP (polymethylpentene), both tough and resistant to high temperature. Some photographic chemicals stain PP, POM and PMP but this takes some time. Graduates used for proportioning concentrates are unlikely to be in contact with nasties for more than a few minutes, so all are quite safe. Paterson graduates are moulded of PS (polystyrene).
I am surprised that some people get out of bed in the morning in case they hurt themselves!

I have 2 x 100ml graduates and 2 x 50ml and to be hones they are not brittle. They are made from Pyrex glass which is TOUGH. They have tipped over on the bench and at one time I dropped one into the sink. It literally just bounced! I also have a 500ml and 1000ml, again made from Pyrex and like the 50's and 100's they are certified accurate and trying them against one of the Paterson 2lt jugs, the jug is very definitely not accurate. the 2lt measuring bar is about 50cc over the stated quantity. That is another reason why I use glass out of preference
Reply With Quote
  #10  
Old 12th September 2020, 07:47 AM
Lostlabours Lostlabours is offline
Friend
 
Join Date: Apr 2012
Location: West Midlands/Aegean
Posts: 1,988
Default

Quote:
Originally Posted by JOReynolds View Post
I note that some scientific and medical laboratories handling chemicals still use glass graduates but in general glass is regarded as hazardous and they substitute PP (polypropylene), virtually unbreakable, POM (polyoxymethylene) and PMP (polymethylpentene), both tough and resistant to high temperature. Some photographic chemicals stain PP, POM and PMP but this takes some time. Graduates used for proportioning concentrates are unlikely to be in contact with nasties for more than a few minutes, so all are quite safe. Paterson graduates are moulded of PS (polystyrene).
I ran a precious metal testing lab, I still have some glass graduates in my darkroom but they are a bit impractical and you don't need that high degree of accuracy with photo chemistry.

I use the 10/11 ml plastic graduates that came with Photocolor kits to measures my film developer or a syringe.

Ian
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 11:16 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.