Homemade film holder for Jobo processor

I'm trying to construct a film holder for processing 50 foot lengths

of 8mm motion picture film in my Jobo CPP-2. I checked with Jobo,

and they don't make a holder or reel for processing 8mm film in their

rotary processors. So I decided to try to make one.

I cut a 21.5 inch long piece of 4 inch diameter schedule 40 PVC pipe

(4.5 inch outside diameter) to fit snugly into my 2850 drum. With a

circumference of just over 14 inches for the PVC pipe, this length

will easily accommodate 50 feet of 8mm film wrapped around it.

The outside of the pipe is about 1/4 inch from the ridges that run

the length of the inside walls of the drum, so there's plenty of room

for chemicals to flow around the pipe inside the drum. The idea is

to wrap the 50 feet of movie film around the outside of the pipe, put

the pipe in the drum, and develop using a B&W reversal process. The

fluids get dumped into the inside of the PVC pipe. To allow for

fluids to reach the film on the outside of the pipe, I cut 50 or so

three inch long slits all over the pipe, and bored a bunch of round

holes near each end.

To ensure that the film doesn't shift and overlap the next turn, thus

preventing development, I thought I might glue a spiral of some thin

material around the tube from one end to the other separated by an

8mm film channel gap. I can tolerate a maximum width of 4mm for the

film channel material and still be able to fit 50 feet of film on my

PVC tube. At The Home Depot, I found some 14 inch long nylon cable

ties that are 4mm wide. Seemingly perfect. Only, I haven't been

able to find an adhesive that will bond the nylon ties to the PVC

pipe. I've tried PVC cement, Super Glue, and a quick set epoxy.

Super glue worked the best, but that's not saying much. I was still

able to pull the fully cured super-glued nylon ties off the PVC pipe

with very little effort.

I'd like some help, if any of you have any ideas. Is there an

adhesive that will bond nylon to PVC? Is nylon even a good choice

for use in film processing? I believe nylon fares poorly when

subjected to strong acids, like the sulfuric acid in the Kodak R-9

bleach, and the acetic acid in the fixer. Is there something else

that might work for the film guide strip? Should I scrap the idea of

using PVC and go with something else? If so, what other material

would be as easy to work with, and reasonably inert to photo

chemicals?

I've tried open tray development with the film wrapped around an

11x14 plexiglass frame, but the results weren't satisfactory. It's

almost impossible to prevent some film overlap here and there, the

film can be broken fairly easily, large quantities of chemicals and

lots of space are needed, and most of the process must be carried out

in the dark. I also have a Morse G3 processor that I haven't tried

yet, but if I'm going to use a processor, I'd much prefer to use my

Jobo than a manual rewind processor. Any ideas welcome, including

ideas involving entirely different approaches, but I'm most

interested in ideas that will let me use my Jobo.

First of all nylon will tolerate acids etc. However, it does have the tendency to swell in wet situations by up to 10% and that should be taken into account. I know of no adhesive that will bond the two together. The material that came to mind, for me, was teflon which is available from Small Parts in sheets that have a etched side for fastening with general purpose epoxies. The problem is the inside of your PVC tube. It is not etched and consequently will not have a "tooth" for the epoxies to adhere to. If you can work that problem out, then this combination may work. Additionally the teflon sheets would need to be cut into strips of the proper dimension. You may want to check www.smallparts.com for additional ideas. Good luck.

Regards,

Donald Miller

Have a machine shop lathe turn a shallow spiral around the PVC

pipe. The groove should be about 1mm wider than the film, and

about 2 or 3 mm deep. Remember to re-calculate the new

circumference of the groove.

Thank you, both. Donald, Small Parts Inc. looks like a great resource for all kinds of specialized materials.

I got the impression that nylon was not especially suited to acidic environments from the Chemical Resistance document on the Honeywell web site here, in case you're interested:

http://www.honeywell-plastics.com/literature/pdf/GEN006.pdf

Reinhold, the lathe idea might be the simplest approach. I'll check that out. It occurs to me the weight of my PVC pipe may put strain on the Jobo motor, so I'll test that first.

Skip;

You may want to check out the "flicker" website, which is dedicated to small-gauge film. They have lots of links.

One idea I have had, but haven't built yet, is similar to yours, but is a hand-cranked drum which can be set over a tray, with the bottom of the tray immersed in chems. My idea is to install a series of pins in 4 rows around the drum, spaced appropriately for 8mm film. This will keep the film from touching or overlapping as its wound around the drum. Just remember to wind the film emulsion side out (duh).

Hey Joe. You're right, the Flicker sites do have a number of good links to small gauge filmmaking sites. I've perused a lot of the 8mm and Super 8mm web sites, and I've found quite a lot of advice for home movie film processing. Aside from one person who has used a Jobo rotary processor to process loose film that was just dumped into a drum, I haven't found anyone who has reported using a Jobo in a more controlled fashion. The results of processing loose film in a Jobo is said to be "interesting", but that's not really what I'm after :).

The Morse G3 rewind processor is discussed frequently, the Russian Lomo reel and inversion tank, the 11x14 rack for tray development, loose film in buckets or trays (or Jobo drums), or in garden hoses, etc., all well described. I'm just hoping I can take advantage of my CPP-2 to achieve better results than what can be obtained by those other methods.

The roller and tray device you describe sounds like some of those on this site here:

http://www.siltec.co.uk/amovies/prom/prom304.htm

It seems like a way to obtain good quality, but I think it might take about as much chemistry as the open tray or bucket methods, plus it would have to be done in the dark. Light's on operation and lower chemical costs are what I'm after.

Its an ooold thread but maybe still interesting... A while ago I built my own drum (not

owning

a CPP yet) and it works very well. Check this <a href="http://

www.peaceman.de/

inhalt/schmalfilm/super8/HT-Rohr-Super8-Entwickler.en.html">DIY

tank</a> I built, it also has pictures of how I solved the spiral threading.