Stirbar magnet in the tube: Anyone ever try it?

[emo supremo]

I work in a drug and development lab and teflon-covered magnets driven by magnetic stirrers are ubiquitous in the building. So, has the Darkroom crowd ever entertained the idea of popping a stirbar in a flat bottomed container?

This is a rather chaotic plenum of flow and might be a cheap alternative to "lift" (if you guys start bustin me up with those 'lift and separate' jibes I'm not going to tell you how well this works.

[Bob Salomon]

Use to use them to mix developers and fixers but not to develop film or prints.

[Oren Grad]

Yes, I've considered it, but no, I haven't done it.

I worked in several research labs during my undergradate and graduate school days and used magnetic stirrers all the time. For a while I thought about getting one of those combination hotplate/stirrers for mixing my D-76, but lately I haven't been having much trouble getting the powder to go into solution. I've never had an problem with other powder chemicals, so the need just isn't there now.

If you meant using a magnetic stirrer for agitating during film development, no way. Surely it would cause nasty standing flow patterns.

[wfwhitaker]

What kind of container are they intended to be used in, if not flat-bottomed?

[emo supremo]

Well that was my point. I've read that a tube processing leaves streaks unless the agitation is in two dimensions (I guess that is what the lift does when the tubes are in a processor e.se bobbing on the surface of a water bath).
I was thinking of suspending my 120mm film spirals (three at atime) in one container above a spacer with the magnet. for the 4x5 I was wondering how the stirbar would operate with a combitank or some such (not a big deal bec small volume of developer). Maybe no advantage for vertical stirring if there is streaking. Just thinking out loud.

[Oren Grad]

Well that was my point. I've read that a tube processing leaves streaks unless the agitation is in two dimensions (I guess that is what the lift does when the tubes are in a processor

The Lift on a Jobo is there purely to dump the solution from the tank at the end of a process step and to funnel the next solution into the tank without having to remove the tank from the processor. It doesn't do anything during the process step.

[emo supremo]

Really!? See, I thought it was for creating a chaotic wobble so the print doesn't get circular streaks. One step closer on the path to pure knowledge.
I used to use drums with a table -top drive motor but both tubes I tried leaked. I'm going to try a Jobo or BTZS and keep the convention with horizontal processing with less chemical. I'm going to try mixing up my own color reversal chemistry again. Any problems with neg development or paper development in these two brand/manufacturers?

[emo supremo]

BTW: having never used one of the aforementioned tubes I am a little worried about the weight of a filled tank. In the forefront of my mind is a post on this forum about the handle breaking of someone's lift...sound like the arm should be treated like a fuse. Is my memory on target i.e the handle is breakable or subjected to large loads or something like that...is that true? I think it was a jobo CP or some such processor.

They sound neat. Do I want one of them too?

[emo supremo]

Hey, I'm losing the light. Gotta go make negatives. Thanks for thinking out loud with me.

[Oren Grad]

BTW: having never used one of the aforementioned tubes I am a little worried about the weight of a filled tank. In the forefront of my mind is a post on this forum about the handle breaking of someone's lift...sound like the arm should be treated like a fuse. Is my memory on target i.e the handle is breakable or subjected to large loads or something like that...is that true? I think it was a jobo CP or some such processor.

They sound neat. Do I want one of them too?

I did break a Lift handle once, though it was partly my fault. They're a bit dainty, but can be reasonably durable in use if you keep the drum weight within reason, are careful not to jerk the handle with lots of weight on the other end, and when lifting and lowering, you support the tank and the long bracket on which it sits, from underneath.

They're neat. :)

[emo supremo]

If you had to do it over again, would you go with the tubes floating in a water bath like the BTZS or with a Jobo system?
Like I said, I had the table top motor drive and wasn't crazy about it leaking blix.

[Oren Grad]

I used the 4x5 BTZS tubes once, during an impromptu workshop in Phil Davis's darkroom in Ann Arbor. And I got started developing 8x10 with a couple of the heavy, early-version 8x10 BTZS tubes, which I still have tucked away on a shelf in my darkroom.

If I had to start again it would be with a Jobo system. Wouldn't even be a close call. But if one is on a tight budget, the BTZS tubes are certainly practical too - I don't mean to imply that there's anything fundamentally wrong with them. For those who like to customize development times on a sheet-by-sheet basis and have the dexterity to chase all those bobbing tubes and keep them straight, it could even be argued that the BTZS tubes are more convenient.

I've not had leakage problems with any of my Jobo tanks or drums or with my BTZS tubes.

[jeroldharter]

I have both Jobo and BTZS tubes and prefer the BTZS for the reasons Oren Grad mentioned. The BTZS tubes do require some organization and management. But the Jobo is big and noisy, all sheets have to be developed for the same time/developer/dilution. The Jobo drums are priced very high.

I was a chemistry major long ago and we used magnetic stirrers all the time. I have two in my darkroom and use them when mixing any dry chemicals. Takes all of the labor out of it. The only downside is that the top surface on most of them is a bit small for a 4000 ml beaker. You have to be careful that the vibrations don't knock the beaker off the platform. I used to walk away for 20 minutes and come back later until a gallon of Xtol splashed all over my darkroom.