Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,723   Posts: 1,515,021   Online: 1215
      
Page 2 of 5 FirstFirst 12345 LastLast
Results 11 to 20 of 45
  1. #11
    Alex Hawley's Avatar
    Join Date
    Jul 2003
    Location
    Kansas, USA
    Shooter
    Large Format
    Posts
    2,895
    Images
    63
    Quote Originally Posted by fingel
    This just proves my ignorance in chemistry, I was going to ask if he uses Lipton or some other brand and how many tea bags/leaves per liter do you use.
    Me too Scott. With all the exotic brews running around, I had to ask to make sure.
    Semper Fi & God Bless America
    My Photography Blog

  2. #12

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    Quote Originally Posted by fingel
    This just proves my ignorance in chemistry, I was going to ask if he uses Lipton or some other brand and how many tea bags/leaves per liter do you use.
    You really don't want to drink this "TEA."

    Triethanolamine is an organic with a pH in the 9 to 10 range. It is quite toxic when ingested. When it is used as the Pyro solvent (without water), it acts as a Pyro preservative. When water is added, it acts as an organic alkali.
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  3. #13

    Join Date
    Nov 2003
    Location
    Avesa-Verona
    Shooter
    Large Format
    Posts
    156
    Thank for the formula and comments. May be Pat Gainer the formula creator or others users of Pyro-TEA have something to add before I start my test?

  4. #14
    gainer's Avatar
    Join Date
    Sep 2002
    Posts
    3,726
    Images
    2
    Nope. Go at it and report.
    Gadget Gainer

  5. #15

    Join Date
    Nov 2003
    Location
    Avesa-Verona
    Shooter
    Large Format
    Posts
    156
    My chemical store is on holidays, no TEA until 20 August, so I have time to last questions:
    a) the TEA need a special temperature or it will work at ambient degrees (around 24/25 C degrees her in summer)?
    b) I guess that also pirocatechin will have the same caratteristics if disolves in TEA, any idea how many grams? 100 grams could be good in your opinion?
    Thanks

  6. #16

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    In the March/April 2004 edition of Photo Techniques, Pat Gainer published his
    CAT-P-TEA formulation:

    Triethanolamine------100 ml
    Phenidone------------0.2 grams
    Pyrocatechol---------10 grams

    Heat the triethanolamine to dissolve the phenidone and pyrocatechol.

    For use, dilute 1 part CAT-P-TEA with 50 parts of water
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  7. #17

    Join Date
    Mar 2004
    Location
    Southern California
    Shooter
    Multi Format
    Posts
    3,879
    Images
    11
    Quote Originally Posted by ongarine
    a) the TEA need a special temperature or it will work at ambient degrees (around 24/25 C degrees her in summer)?

    Thanks
    In my experience the TEA developers will work from 20 degrees C (and probably lower) through 25 degrees C (and probably higher).

    You can use the Ilford Microphen time/temperature charts to estimate the effects of temperature on developing time.
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  8. #18
    gainer's Avatar
    Join Date
    Sep 2002
    Posts
    3,726
    Images
    2
    I must add that this Cat-P-TEA is the essence of and inspired by Sandy King's Pyrocat HD.

    A source of pretty cheap TEA and propylene glycol is www.chemistrystore.com.
    Gadget Gainer

  9. #19

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by gainer
    I must add that this Cat-P-TEA is the essence of and inspired by Sandy King's Pyrocat HD.

    www.chemistrystore.com.
    Just curious what might result if you added a little phenidone to the Pyro-TEA formula. Pyrogallol is superadditve with metol and I would assume that it would also be superadditive with phenidone? If so the addition of phenidone should produce a big boost in developer energy.

    Sandy

  10. #20

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by jdef
    I've been meaning to try adding a little metol or phenidone to the P-TEA, but I have only gone as far as to mix it 50/50 with the PG/PQ concemtrate, which produces an entirely different developer from either of the "parent" developers. Regardibg Cat-P-TEA; could one sibstitute hydroquinone for the catechol?
    I am sure you could substitute hydroquinone for catechol because several popular developers are based on this combination. However, you can not make an equal parts substittution of hydroquinon for catechol in the case of Pyrocat-HD without dramatically changing the working qualitiy of the develper. I am saying this based on experience because I have actually tried it.

    I am going to assume that the substitution of pyrocatechin with hydroquinone in equal parts in the Cat-P-TEA formula would not work as well but I don't know that for a fact since I never actually tested it.

    Sandy
    Last edited by sanking; 08-07-2004 at 10:18 PM. Click to view previous post history.

Page 2 of 5 FirstFirst 12345 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin