Twirly Thingy Tank

[kq6up]

I had someone donate 4 twirly thingy tanks to one of my students. I have never worked out a technique to get consistent results with these things. I have a Paterson tank and quickly abandend the twirly doo-dad for inversion. However, these tanks do not seal, so they have to be agitated via the twirly thing. Can someone share a technique that gets consistent results with these ancient tanks.

Thanks,
Chris Maness

 

[Gerald C Koch]

Sometimes a gift isn't really a gift. Not the best tanks for teaching students proper technique.

 

[tomalophicon]

Yes, rotate one way then the other in a random pattern. I find they work really quite well.
I rotate for 10 seconds every minute in a non-gentle way

 

[Kevin Caulfield]

The tanks do need to be "burped" to ensure that they seal. To "burp" a tank you press down on the lid whilst you close it. You can pretty much hear the air flow out.

 

[removed account4]

you can get them to seal if they still have the plastic gasket, and you smear the gasket
and lid with vaseline. i have one but never really use it anymore ...

 

[Rick A]

Sounds like some old Yankee tanks that arent meant to be inverted. To "burp", or knock air bubbles loose from the film, just give the tank a couple of raps on the counter, but not so hard as to crack the plastic. Another thing that can be done to remove air bubbles, is add one drop of Edwal LFN to the developer just before pouring into the tank. Agitation is accomplished by some forceful swirles of the stick, in a back and forth motion. I had a couple of these tanks back in the 60's, and always had good negatives using them.

 

[Mike Wilde]

I know the old non invertable yankee tanks. I 'cut my teeth' on them.

I was tought to rap , gently, to dislodge bubbles, and then agitate when required by sliding them in a figure eight pattern on the counter.

 

[Steve Roberts]

I never use anything else. In fact, I've just specifically bought another such tank.
As well as allowing rotation in both directions, mine have a spring-loaded plunger in the base so that by depressing the 'twirly thingy' an amount of up and down motion can be imparted. As the total opposite, my pet hate is for inversion agitation tanks, as a)they never quite seal and the inversion process sooner or later leaves a trickle of the contents running down one's arm and b) when the tank is sat in a water bath to maintain a constant temperature, the very act of lifting it out once or twice a minute sends water all over the place.
Steve