Using a Jobo forced film washer

Discussion in 'Darkroom Equipment' started by adelorenzo, Dec 1, 2013.

  1. adelorenzo

    adelorenzo Subscriber

    Messages:
    791
    Joined:
    Mar 10, 2012
    Location:
    Whitehorse, Yukon
    Shooter:
    4x5 Format
    I just picked up one of these. Seems like a simple device but I can't find any instructions online.

    If I had to guess I would say that you pop the lid of the tank but leave it on loosely, then insert the washer. So the water flows down the column and then back up and out the sides of the tank.

    Can anyone confirm or correct?
     
  2. miha

    miha Member

    Messages:
    1,217
    Joined:
    Feb 15, 2007
    Location:
    Slovenia
    Shooter:
    Multi Format
    Push it firmly into the centre opening of the tunel, open the water tap carefully, water flows out trough the openings in the tank lid. Now close the little hole on the transparent tube with your finger, this will close the air intake, the water will rise in the tube. Adjust the water flow with the tap so that the water level is steady between the two red lines on the tube, then unblock the air intake again.
     
  3. adelorenzo

    adelorenzo Subscriber

    Messages:
    791
    Joined:
    Mar 10, 2012
    Location:
    Whitehorse, Yukon
    Shooter:
    4x5 Format
    Thanks! It was a little more complicated that I thought, that is very helpful.
     
  4. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,772
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    OTOH, you can just let fly with the water pressure and ignore the lines. After you finally grab the hose and nozzle whipping madly around the room and clean up the mess you can follow the instructions in #2.

    :D

    PE
     
  5. MattKing

    MattKing Subscriber

    Messages:
    16,803
    Joined:
    Apr 24, 2005
    Location:
    Delta, BC, Canada
    Shooter:
    Multi Format
    As is often the case with PE ...

    Clearly the voice of experience.
     
  6. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    Last edited by a moderator: Dec 1, 2013
  7. mohmadkhatab

    mohmadkhatab Member

    Messages:
    1
    Joined:
    Nov 30, 2013
    Location:
    cairo
    Shooter:
    Multi Format
    My dear brother, how did you get those great machine,,, I'm thinking of buying one, I'm trying to gather information about the cost.

    Could you help me in this matter?
    Does that machine to show the potential and the development of the "positive film."
     
  8. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
  9. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,772
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    Jobo washer from a Jobo manual

    Here is their own photo of the washer. They do call it a "cascade", but I just don't associate that name with this device.

    And my only wall decorating was done with a Kodak style emulsion mixer made for me by a friend. When we first tried it, lets just say it "overperformed" a tiny tad!

    PE
     

    Attached Files:

  10. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    That water running over the tank over a staggered relief makes the term cascade quite appropriate.
     
  11. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,772
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    Well, I can get about the same effect with a piece of tubing and a cork. However, cascade it is called so cascade it is.

    PE
     
  12. adelorenzo

    adelorenzo Subscriber

    Messages:
    791
    Joined:
    Mar 10, 2012
    Location:
    Whitehorse, Yukon
    Shooter:
    4x5 Format
    Nonetheless it seems like a pretty handy thing. Thanks for the info everyone, better try a test run before I use it with film!

    I still have to figure out some way to make it fit my water source as well.
     
  13. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    As that sketch #1 in the manual shows,a 1/2" nipple with flange should fit. From there you should be able to go anywhere.
    Alternative try to fit a shower hose, or go via step-up nipples and tubing.


    EDIT:
    With that shower hose I refered to adapting a Cascade to a bathroom installation, not just putting the shower house directly onto the tank.
     
    Last edited by a moderator: Dec 2, 2013
  14. Sponsored Ad
  15. Seele

    Seele Member

    Messages:
    194
    Joined:
    Feb 2, 2004
    Location:
    Sydney Austr
    The Cascade is different because it uses air bubbles to do most of the washing, not just water alone. Sure you can just shove a hose down the centre column of a tank but there is a possibility for some stale spots inside the tank where little fluid is replenished, so the Cascade was designed to force a lot of air bubbles into the tank where the inside is vigorously agitated.

    While it washes the negatives very well along with low water consumption, I only use it when I fix my films with hardening fixer. Otherwise, I use the Ilford 5-10-20 method; after all as an Australian I tend to be quite frugal with water.
     
  16. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    Yes you are right. A laminary flow might produce spots/areas of lesser washing (similar to some artefacts seen in rotational tank development).

    The ventury principle implemented in the transparent part of the Cascade adds air bubbles to the water streaming through the reel.
    On the other hand are we just afraid of air bubbles in the reels during rotational processing. So it depends what works out best to deliver best diffusiion in each application.
     
    Last edited by a moderator: Dec 2, 2013
  17. RalphLambrecht

    RalphLambrecht Subscriber

    Messages:
    8,211
    Joined:
    Sep 19, 2003
    Location:
    Florida
    Shooter:
    Multi Format
    please keep in mind, there is nothing simpler than film washing,after 2min in washing aid, just insert the hose into the developing tank and slowly let fresh water enter the tank for 10 min; wipe off ecess water between two fingers and hang to dryin a dust-free warm place;done. forcefull washing is not required. even if you was the film in Niagra falls, if would not wash any quicker. a slow constant supply of fresh water is all it takes.
     
  18. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,772
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    If you use a plain hose, it will wash well, but air bubbles will form and block proper washing. So, with a simple hose, one must tap the reel about once per minute to break up the bubbles and promote good surface water flow over the film.

    PE
     
  19. RalphLambrecht

    RalphLambrecht Subscriber

    Messages:
    8,211
    Joined:
    Sep 19, 2003
    Location:
    Florida
    Shooter:
    Multi Format
    so what keeps these bubbles from forming in film washers?:bli:confused:
     
  20. Photo Engineer

    Photo Engineer Subscriber

    Messages:
    25,772
    Joined:
    Apr 19, 2005
    Location:
    Rochester, NY
    Shooter:
    Multi Format
    The hole in the Jobo cascade washer is a "breaker" or some such name. It makes the small bubbles form larger ones and the large bubbles do not stick to the film (or paper). They tend to float off. However, I find it a good idea to check the film for tiny bubbles even with the Jobo washer.

    Oh, and the Nitrogen burst agitation introduced by EK for color processing served a similar purpose along with agitation.

    PE
     
  21. AgX

    AgX Member

    Messages:
    11,904
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    That hole is necessary to yield that venturi-effect.
    (That effect is only to be obtained with a tank connected to it. The flow-rate with the water level adjusted between those marks is about 3L/min)

    Whether those added bubbles interfer with possibly all existing bubbles is still the question. As this apparatus is employed in the last bath consistant bubble-forming on the film will not be visible in its outcome. As will the effect of bubbles (at high flow-rate) or the lack of them (at low flow-rate or even better with closed hole) not be visible.
    Without further tests on the emulsion layer we just have to thrust Jobo that those added bubbles are beneficial.


    (Terminology: I have it about a venturi-effect or even venturi-apparatus. Actually the thing is not designed that way, to produce large suction force. Rather to make bubbles. And this it does by injecting its water stream at high velocity into the dammed-up water from the tank, and taking with it air out of that transparent casing. Thus it is better called an injector-system. That hole is the way for that air to get in.)
     
    Last edited by a moderator: Dec 4, 2013
  22. gliderbee

    gliderbee Member

    Messages:
    117
    Joined:
    Jan 18, 2008
    Shooter:
    Med. Format RF
    So is it correct that the tank lid does NOT have to be loosened for using the cascade?

    regards,
    Stefan

    Verstuurd van mijn GT-P7510 met Tapatalk
     
  23. miha

    miha Member

    Messages:
    1,217
    Joined:
    Feb 15, 2007
    Location:
    Slovenia
    Shooter:
    Multi Format
    Correct, the lid stays closed.
     
  24. gliderbee

    gliderbee Member

    Messages:
    117
    Joined:
    Jan 18, 2008
    Shooter:
    Med. Format RF
    Thank you! That's how I used it for quite some time, but was told otherwise recently, so I had to ask.

    regards,
    Stefan

    Verstuurd van mijn GT-P7510 met Tapatalk
     
  25. RalphLambrecht

    RalphLambrecht Subscriber

    Messages:
    8,211
    Joined:
    Sep 19, 2003
    Location:
    Florida
    Shooter:
    Multi Format
    any hose ,fitting the top hole in the lid will work just fine.film washing does not require a forced water stream. slowly running water is sufficient.:tongue:
     
  26. Sirius Glass

    Sirius Glass Subscriber

    Messages:
    20,588
    Joined:
    Jan 18, 2007
    Location:
    Southern California
    Shooter:
    Multi Format
    I just repeated pour water into the tank, let it turn for 30 seconds, and empty the tank using the lift.