stand developing problem

mornin'

There has appeared an area darker than the rest, after an hour of development in rodinal 1:100 at 20 degrees, agitated (inversion) for the first 30 seconds then for 10 seconds on the 20/40/50 minute (stopped: 20seconds, fix: 2 minutes), the negative developed well and mostly uniform except this one area about 1cm right along the one edge of the film.

is this caused by developer sinking to the bottom of the tank, or not enough fixing, stopping, developing?

I've attached a scan of one frame for everyone to have peak at, some are more prominent than others and on one frame looks like waves (too much agitation)... so I'll stick that one up too.

thanks in advance

I don't know the answer for sure but are you certain that the film was completely submerged in the developer? (i.e. Did you put enough chemistry into the tank?)

I did, but the reel may be sticking on inversion... still should be submerged tho'

Are they plastic or stainless reels? What size film? I've had plastic reels with 35mm film try to float or hang up in the tank. It does look like you did not get developer for the full time.
juan

plastic reels and 120 film.
looks like I could do with something to hold the reel at the bottom of the tank.

**looks like I'm actually missing a part of my tank.

If you have excess space above the reel (or reels) you can cut a piece of pvc pipe of the right diameter to fit over the core tube. You want to cut it just long enough to clear the top so that when you close the tank, the pipe will keep the reel on the bottom and leave a little clearance from the top of the pipe to the underside of the tank lid.

Don't you have a plastic C-clip that goes around the center tube to keep the reel from riding up?

All of my plastic tanks have them. When I use a single reel, either 120 or 35, it needs to be on there or else the reel has a tendency to ride up. The only time I don't need it is when I have two reels (in a two-reel tank) which fill the entire vertical space.

Sometimes, if those clips get old, they don't hold tight enough. They either crack or lose their elasticity and, thus, can't grip the center tube.

If you have clips and you used one, check it to be sure it holds. If you don't have clips, look for some. If you can't find any, I like Ian's idea.

In fact, I just might do that instead of using clips. I imagine that might work better.

no I don't have the clip... funny how the strangest things can walk away.

I'll have to try Ian's ideas, thanks Ian

If it is the size of tank that holds more than 1 reel of the given size and you have spare reels you can just add empty reels to the column above the loaded reel. This will stop the reel sliding up the column.

I don't think paterson tanks come with C clips.. I 've never gotten one with any.. only with second hand ones at markets.

Just put another reel above it is another solution.

My Paterson tank & reels set came with a C-clip, but that was some years ago.

I'd concur the reels not dropping back down after inversion is likely the problem. I've had it myself when I forgot to put the clip on.

I made a small "stopper" from half a film pot, so hopefully that'll do the trick.

thanks everyone