processing baryt in jobo drum
hello people ! i d like to process the b&w baryt paper in a jobo drum...could you tell me the difference in processing between tray and the jobo drum??
p.s. for baryt paper in tube could i use only water for stop bath??
? Baryta is found on many (all?) papers, RC and Fiber Based. The RC paper will be fine in the Jobo drum, but the back side of fiber based papers will likely cause a problem with chemical contamination.
I would use acid stop to make sure any developer trapped behind the RC paper (and nooks-and-crannies of the drum) gets deactivated in a timely manner. If you are going to do 'one shot' processing, you may want to calculate (from product datasheets) the minimum amount needed. If you re-use the chemicals, you can put in more than needed, since you will be re-claiming it anyway.
I would try one-shot with the developer and stop bath. I'd wash the prints outside of the drum. Dektol requires about 30 ml per 8x10 at 1:2 dilution. A Jobo 1526 drum requires 40ml, so I'd use 40ml and you are above the limit by 10ml. At 68 degrees I'd develop for 2 minutes. I'd use 40 ml of stop bath at 1 minute and so on...
There are a lot of paper fixing strategies out there. I'd probably try ammonium thiosulfate and use 40-50ml one-shot for 1 or 2 minutes.
Well, just to nit pick a bit.
Baryta is used in only FB papers. RC papers use Titanox.
Baryta = Barium Sulfate, Titanox = Titanium Dioxide.
I not so sure that it will work, as fibre based paper will sag when fully wet in a way RC paper holds up its shape (as the core never gets soaked during normal developing times). Be sure to do some tests first, where you can use a scrap FB paper picture and ordinary water for the full processing time. Or just try it with a test strip of both RC and FB paper in a water tray, so that you will see what I mean.
In a word RC is stiff and stays that way when wet.
Originally Posted by edtbjon
One more reason I like FB, handles easy. Dan
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
The back of the FB paper can stick to the inside of some drums. Jobo gives specific instructions for this but OTOMH IDK what they are. If it sticks, they say it is very hard to remove.
At one time, they did have a special Saran type netting that went behind the print which was also used for film, but these instructions changed when the netting was no longer available. Sorry I can't remember details. I avoid FB in drums.
FB developing in Jobo drums causes no problems. I have never done (30 yrs) anything else.
Normal developing and fixing times. Washing outside the drum.
prewarm = 1 minute
dev = 3 minutes (Ilford MG 1+9)
stop = ½ minute
fix = 1 minute (Ilford Rapid 1+4)
Release, the best you can do...
Yes, I don't know what I was thinking...probably too many barium enemas...
Originally Posted by Photo Engineer
Originally Posted by danzyc
I've been processing all my b/w papers exclusively in drums for years.
That includes thinner papers like Azo and various double weight papers like
Forte and, now, Emaks (from Freestyle). I've also used a number of different
drums...some of them were actually nothing more than pvc tubes with screw
on caps. To pull paper out of drums without those ribs on the inside I simply
filled with water...the paper detaches and pulls out without a problem. Right
now, I'm using a JOBO drum for 16x20 prints. I hand roll them on four wheels
mounted on a wooden board. I usually turn the drum about 8 rotations, then
reverse 8 rotations, back and forth. Anyway, I have yet to encounter any
problem at all, no matter the style of drum.
Hope that helps some.
I just realized I didn't really answer your question. Sorry about that. Speaking for myself...developer is one-shot method, 200ml minimum for 16x20. 100ml minimum for 8x10s. Plain water for stop bath. Fixer...ammonium thiosulfate...same fix times as tray fixing....and of course, maybe not of course, I DON'T wash prints in drums. I use an old Zone VI print washer......and a tray for 16x20s, exchanging water every five minutes for 30 minutes, sit overnight, then 15 minutes next morning.