Manual for Jobo Mistral 2 or general answer about drying time

[Diapositivo]

Thanks also to the precious help derived from the participant to this forum, I have developed yesterday my second roll of slides and it seems to me that results are good (I have to scan it yet, but I am generally speaking optimist).

I dry my films with a Jobo Mistral 2, this stuff:

http://www.novadarkroom.com/product/333/Jobo_Mistral_Film_Drying_Unit.html

I bought mine second-hand on eBay and could not find anywhere a user manual, not even on the Jobo web site. So the first question is: does anybody have a user manual for this?

I understand that slides are optimally dried at "high" temperatures for longevity and the higher temperature of the Jobo, 45°C, should be provided for this.

My other questions (and the reason why I was looking for a manual) is: is there a way I can be sure the film is perfectly dried? (Just touching the edge and "feeling" it is dry would not mean a lot because the gelatin might have some residual humidity left)? Is there a way I could damage the film if I leave it for too long under warm air? (45° is pretty warm).

Yesterday I left it for around 30' at 45°, and then for probably two hours with the fan on, at room temperature.

I see that the film remained slightly curved, with the opaque (emulsion) side concave, and the glossy side convex. Not very curved but nonetheless I would prefer, for better scanning, a very flat film. Can drying technique (time, temperature) have an effect on how flat a film dries?

The film is Fuji Astia 100. Maybe other films have a different behaviour?

Thanks
Fabrizio

 

[GeorgesGiralt]

Hello Fabrizio,
If you over dry the film, it will curl in the long length. (due the gelatin shrinking).
I use the Durst equivalent of the Mistral, which has a setting to run the fan without heating.
I run the heater first then after about 20 ~30 minutes, I turn the heater off and let the whole thing cooling off and finishing to dry.
My film (135) are pre-dried as I spin them in a salad drier to remove as much water as I can.
Have a nice day.

 

[Diapositivo]

Hallo Georges,

Next time I will first let the final rinse slide off the film for 10' and then keep it at maximum temperature with fan for 30' as you do, unless somebody calls for a different treatment.

Thanks
Fabrizio

 

[Zathras]

Hello Fabrizio,
(... (Big Snip)...My film (135) are pre-dried as I spin them in a salad drier to remove as much water as I can.
Have a nice day.

This is an intersting idea. Are the films still on the reels when you do this?

Mike

 

[GeorgesGiralt]

Yes, Mike, I put a couple of spools in a diameter, seized with rubber band in the bowl. a friend of mine which salad spinner is bigger than mine use an inversed bowl on the center to seize the spools. I forgot to mention that this also work for 120 film. I use this method with Paterson or Jobo 1500 spools. This way I do not use Photo-flo wetting agent and avoid the problems it cause to the spools.
For large format sheet film, I revert to the Photo-flo bath and fingers squeezing.