jobo drum leking

[RalphLambrecht]

my 35mm jobo drum leaks so badfrom the top cover that al debveloper is drained before the end of the development time. what am i doing wrong?

 

[pentaxuser]

Ralph, have a look at the top lid( not the red rubber cover). It has square black teeth which click over the tank rim. If one or more of those teeth are broken then the lid will still click shut and hold firm but the tank will leak through the missing teeth.

I have just such a tank top with two teeth missing and in 10 minutes of 10 seconds inversion per minute I can lose about 80-90mls. If you are using rotary processing so the tank is lying on its side then the missing teeth might be allowing the liquid to run out every few seconds so my assumption is that the loss of liquid will be more.

I am assuming of course that the plastic tank has not split but if this was the case then you would see the leak when the tank was just sitting upright

I hope this helps

pentaxuser

 

[markbarendt]

Those teeth are a fair bet. They may not be broken simply bent in some and keeping the lid from seating.

 

[Neal]

Dear Ralph,

One other small possibility is a particular top not mating well with a particular drum. I have a top that fits very easily on two of my drums but I have to be more careful on the third. It looks good from a distance, but you can see the problem as the drum rotates.

Neal Wydra

 

[RalphLambrecht]

thanks for all the good advise. i took a look at the lid and no teeth are bent or broken off. tomorrow i'll fill the canister and take a look where the leak is. then i'll inspect the teeth in that area a bit closer.

 

[Diapositivo]

Ralph, I had the same problem. It can happen that the teeth look all seated properly, and the tank looks really closed, but it might be not well closed. I suppose this is because the red collar is not thoroughly pushed toward the tank, ior is not uniformly pushed downward (some parts of the collar are not tightly locked).

My personal solution to this problem is to adopt pre-soak as standard procedure. I "wash" the tank with water in temperature once, let's say for 30 seconds, and discard the water. Then I wash the tank again, this time noting how much water I am inserting into the tank. After some 30 seconds or so, I recover the water in the graduated cylinder and see if there was any volume loss. If there was no loss of water I proceed with treatment.

Fabrizio

PS I know there are "pros" and "cons" regarding presoaking. I adopted it for the peace of mind this procedure gives me about the tank being well closed, rather than for the specific "pros".

 

[RalphLambrecht]

good point!, but not sure what to do if this finds the leak: what then?

 

[Diapositivo]

If I find the leak I simply make sure the orange collar is well tight, meaning:

- I look at if from down to see if all teeth seat correctly and that the orange teeth of the inside of the collar coincide with the spaces between the black teeth; If that is not the case, I would put the tank in the changing bag and repeat the operation putting care in aligning the orange teeth with the "holes" between the black teeth.

If the orange and black teeth are all well aligned and seated I just push the orange collar hard downward, while keeping the tank on a hard surface, to make sure that the collar really is at its maximum downward run. If it leaked water, you should be able to notice the collar to go down some 1 or 2 mm somewhere along the circumference. Those tanks must be closed by applying a pretty much intense force on the orange collar. Don't trust the "click" or the simple sensation that all went to its place. Don't be gentle.

I would then repeat the rinse test with water in temperature and check that there is no leakage. Chemicals would be inserted only when the test reassures me about correct closure of the tank.

I never had any problem since I adopt the test procedure (the tank never leaked) but it's a nice insurance policy and gives me peace of mind.