Spiral tank emulsion in/out

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chrisgavin
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Spiral tank emulsion in/out

Post by chrisgavin » Thu Apr 10, 2014 1:37 am

Hmm,

I've just had a pretty disappointing Super 8 BW neg home processing experience.
This is about the fifth film I've put through my DIY spiral tank, and up until now, the results have been much more rewarding.

As I'm capturing the footage frame by frame, I can see a long band of uneven processing running along the whole length of the film.

The load on to the spiral went badly and took lots of attempts. On previous loads I think I've been careful to keep the emulsion facing to the outside edge of the spiral. Somehow this time, between losing the film end, cracking open the cartridge, snapping the film and reloading repeatedly I must have somehow got the emulsion facing in. As my spiral is made with 5mm wide flat wire, I guess the emulsion side was held tightly against the spiral so not leaving enough space for the developer to get in and do its work.

The band of bad processing seems to pretty much match the width of the spiral so I guess this is the cause of the problem.
Is this something one would expect to see when mis-loading a spiral, i.e. is this a mistake anybody else has made too?

Ah well, looks like I'll have 50 feet of particularly 'experimental' footage to enjoy...

Chris
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aj
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Re: Spiral tank emulsion in/out

Post by aj » Thu Apr 10, 2014 10:06 am

There is no link or such ...

In LOMO tanks it is important to have the emulsion outside and the perforations in the spiral.

To avoid all this hassle the spiral is best loaded directly from the cartrdige. If you do not plan to reuse it.
Yank out 20 cms. Cracking the reverse brake. Best to assemble a holder. It is important to push in the cartridge pressure plate to let the film out real easy and with reduced scratch risk.

The labs used robots to yank out the film and feed it onto large reels which would then be mounted into a processor. This cracking open is an emergency procedure when the user winds in the film completely rather than leave it on EXPOSED.
Kind regards,

André

chrisgavin
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Re: Spiral tank emulsion in/out

Post by chrisgavin » Thu Apr 10, 2014 11:41 am

Thanks aj,

Yep unfortunately the film tail did slip inside the cartridge, so the 'emergency measure' of cracking open the cartridge was required.
I had this happen once already last year, so as soon as it happened again, I had some idea of the difficulties this would cause.

This time, the 'knock on' effect of the mistake escalated into worse problems too. Not being able to load the spiral, then getting into a major darkroom (confined attic space) tangle and the hell of not really knowing which side of the film was which any more.

It's really SO much better to keep the film end and feed it out from the unbroken cartridge.

I've made this mistake twice now, and really hope to not go there again...

There are probably a few design changes I can make to the spiral which might help a bit also.
Hopefully it'll go better next time.
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richard p. t.
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Re: Spiral tank emulsion in/out

Post by richard p. t. » Thu Apr 10, 2014 12:36 pm

Personally, I always open the cartridge and take the spool of film out, holding it in my hand as I load. Yes, some labs use a super 8 auto loader which pulls the film out as AJ suggests, winding it onto a big spool ready for loading in a processing machine.
AJ is right that with a lomo, you normally load with the emulsion facing out. With a lomo, if you load with the emulsion in, you get a line, but it is not usually in the picture area even with super 8. But it is a line of unprocessed film which looks different of course.
bw negative is the hardest process to do in a spiral tank by the way.
cheers,
richard
I run Nano Lab - Australia's super8 ektachrome processing service
- visit nanolab.com.au
richard@nanolab.com.au

nikonr10
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Re: Spiral tank emulsion in/out

Post by nikonr10 » Thu Apr 10, 2014 1:02 pm

chrisgavin wrote:Thanks aj,

Yep unfortunately the film tail did slip inside the cartridge, so the 'emergency measure' of cracking open the cartridge was required.
I had this happen once already last year, so as soon as it happened again, I had some idea of the difficulties this would cause.

This time, the 'knock on' effect of the mistake escalated into worse problems too. Not being able to load the spiral, then getting into a major darkroom (confined attic space) tangle and the hell of not really knowing which side of the film was which any more.

It's really SO much better to keep the film end and feed it out from the unbroken cartridge.

I've made this mistake twice now, and really hope to not go there again...

There are probably a few design changes I can make to the spiral which might help a bit also.
Hopefully it'll go better next time.
What i found with DIY home cooking is that you will make mistakes on the way ! as you learn ,that just life /it,s how you deal with it in the moment ? ie in the dark and film not loading into tank my case lomo , always keep a light tightbox on hand that way if you lose your way can at least bucket process or feed into a 35mm film tank , I alway load from the cart as AJ has wrote about , Its easy that way ? it's take's time to learn and master,
or buy a lomo tank ,

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Re: Spiral tank emulsion in/out

Post by chrisgavin » Thu Apr 10, 2014 9:16 pm

Thanks for all the suggestions.

Yes, developing your own films at home using home-made equipment and sometimes home-made chemistry is certainly a 'trial and error' process. I've discovered that about 1/3 of my 'ruined' film turns out to be OK: I must have got at least the first section of the film the right way round before the film break happened. The other 2/3 is pretty rough, but does have have a certain 'post apocalyptic' feel which I might just cut into my film anyway!
: )
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wahiba
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Re: Spiral tank emulsion in/out

Post by wahiba » Fri Apr 11, 2014 12:04 pm

I unwind the films onto spools and then load the spirals from the spools. I made a fixture that allows a pair of cartridges to be wound onto spools simultaneously.

I actually managed to wind spools from cartridges and then to load both spools onto the spirals of my Lomo tank using a large changing bag in one session.

It worked :roll:

Must admit it was some time ago, but it is possible to unload two cartridges and load them into the tank for processing in one session sat at the kitchen table.

Must confess side of emulsion was the least of my concerns at the time. Films were negative and processed OK though.
Decided not to change web-site, just keep updating. New movies at: http://8mmovies.yolasite.com

freddenacka
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Re: Spiral tank emulsion in/out

Post by freddenacka » Wed Apr 30, 2014 2:39 pm

I´m using a Loomo tank and it is rather difficult.
The most important is that you only screw it in the same direction as you spool it when you are developing.
I did in both directions first and then I unspooled the film in the tank witch made bad scratches and so.
I think the result get very good when things are going smote

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