Paterson tanks : 8-reels vs 5-reels and different results...

[Pat Erson]

Hi gang,

I'd like to subject to you the (rather puzzling) results of my latest processing sessions :

I used to process my TRI-X 135 films with one 8-reels Paterson tank. Over the years I got to know pretty much exactly what density I would get based on tank agitation.
A few weeks ago a friend gave me his 5-reels Paterson tank to help me stay on schedule. So I used it : same film (TRI-X 135) same developer (D-76 1+1) same temp (20°C) same agitation pattern and strenght (10 seconds every minute) same time (11').

The negs from the big tank came out fine the ones from the small came somewhat thin and under-developed as if I had cut the developing process at 9 minutes or so. I didn't, the films remained int he dev for 11 minutes.

This week-end I did it again (big 8R tank + small 5R tank) though this time I handled the 5-reels tank rather roughly (= agitation was quite strong). This time the negs from the tank had more or less the same density.

So shall I conclude "small" tanks require much more agitation than the big 8R ones? Quite puzzling for me.

 

[Xmas]

You need to use the minimum quantity in each tank if you intend to invert cause that determines the amount of flow when you invert.

If you bang a multi tank down when it is full of liquid expect a Noah's arch event...

Noel

 

[RobC]

I rekon its an agitation thing. I experienced this years ago when trying out a 5 reel tank compared to a 2 reel tank.

I also rekon the smaller the tank the bigger the percentage of air in top of tank relative to dev volume. So there is a difference but I wouldn't have thought it would be significant but it seems to be.

 

[ParkerSmithPhoto]

You can drop these tanks on a rotary base, plug it in to a timer, and just let it go. Continuous agitation will work fine with D76.

 

[MartinP]

You can drop these tanks on a rotary base, plug it in to a timer, and just let it go. Continuous agitation will work fine with D76.

... until the lid pops off