I don't know the Prinz Jet Drum, but I use a Meteor Standard E, which should be the same in principle.
As was already said, you may place the paper face up or face down on the canvas. However, some drum dryers have an additional tension lever for high gloss (face to the drum). This adds tension to the rollers that press the canvas to the drum. The more gloss is desired, the more pressure is needed.
There are two principal parameters you must find out: temperature and speed. Optimal settings may vary with the paper you use. The optimum temperature is usually around 65°C (150°F). The speed is ok, if the paper peels off itself after one ¾ turn of the drum, usually with loud creaking. The louder it creaks the better, because louder creaks mean that large areas are coming loose at once.
If the emulsion cracks, your temperature might be too high (at least for the kind of paper you use) or you are using some force to peel the paper from the drum. I repeat: the paper must loosen itself. Some paper might need hardener and/or additional aids like Glanzol.
Replacing the canvas yourself is usually not easy but should not be impossible. Anyhow, you'll need some tools for doing that. Don't care too much for the condition of the canvas. Even if it does not look very appetizing, it takes a lot until it actually needs to be replaced. It is usually made of linen an can be washed in a usual washing machine.
Thanks for mentioning the Bon Ami. Being an ex-Navy photographer,
I just tend to throw Brasso at any shiny surface, but we do use Bon
Ami around the house. The form we use is from a powdered
dispenser, like Ajax or Comet. I haven't seen the cake variety.
I'm guessing the powdered form would work just as well.
That makes sense about there being petroleum distillates in brasso.
It took a lot of polishing to get most/all of the oil off the
surface of the drum, and maybe all of it didn't get off and some of
the pitting I have left might actually be from oil on the drum
pulling lint off the apron and pressing it into the emulsion.
Do you recollect if that ferrotyping polish was used in a heated
process or for room temperature ferrotyping? I'm thinking that
probably wouldn't be the ticket on the kind of hot drum + linen
apron glazer I've got.
Very helpful post. One more independant variable to add to the
mix -- roller tension. The other night, I got decided to pull the
apron off the dryer. It took the better part of an hour, but I got
it off, washed it once with soap and bleach, once with soap only,
then dried it on low for a long time, so now it should be
relatively cleaner and have less lint. I'll Bon Ami the drum
before I put the apron back on, to make sure I've got it as
polished as I can and have gotten the oils off from the Brasso.
Up until today, my darkroom has been out of commission and full of
saw- and sheetrock-dust since I've been adding electrical outlets to
the wall, ceiling and a small dry counter. To test the dryer, I've
taken previously printed prints of mine, soaked them in water for
fifteen minutes to an hour, then run them through. I haven't even
added photo-flo to the water, and I haven't run a test yet with the
gelatin mixture, so I'll do that with both of those once I get some
fresh prints, hopefully today.
Also -- as I was disassembling my dryer to get the apron off, I notice
that the wing nut on either side of the unit controlled tension on a
spring attached to what I'll call the primary squeegee roller. This
is the roller that, through the apron, first presses the print against
the drum. There's a corresponding roller (both rubber) on the
opposite side of the drum immediately before the print comes out from
under the apron, but it's fixed and not adjustable.
Sincee my dryer doesn't have adjustable heat or speed (I didn't see
any rheostats when I had it torn apart), perhaps this tension
adjustment might be the next best thing. If I reduce the tension on
the roller at the entrance to the drying path, it might press out less
water and let the print take a little longer to dry.
This is actually quite fun. I had no idea there was so many things to
consider when I dug into this issue. Hopefully, I'll have some
production quality prints to show for the effort.
Anyone have any ideas on the archival impact of the gelatin mixture?
I might be a little leery about using photo-flo on prints. There used to be a product made by Kodak called Ferrotyping Solution. I am not sure it is still around, but no doubt you can get the formulary from any of the multiple choices for such things.
As mentioned by others, heat control and speed will be the key to your success with this dryer. One of the screws you are looking at probably is the adjustment to keep the belt moving straight onto the drum. It would be the one that attaches to the roller closest to the front of the dryer, either directly or by another adjusting pin. How old is this dryer anyhow?
Good luck... looking forward to ongoing reports!
The front-most roller, which I haven't mentioned yet, is mounted on two sliding mechanisms whcih are mounted, in turn, on two screws that I can turn with black knobs on the front of the machine. That's my belt adjustment.
The wing nuts are on bolts that hold one side of tension spring on each side of a large black roller which is the roller which initially presses the apron against the drum as the prints travel into the dryer. The springs only control the amount of pressure exerted by the roller onto the drum itself. There's no space between the roller, apron or drum at this point, so it's not an apron tension adjustment.
Age? I really wish I knew. If the date is encoded in the serial number in some obvious fashion, maybe it's from 1962 or 1972 (more believeable).
Since details about the dryer are cropping up in this discussion, I grabbed some snapshots of it and put them at http://bellavestudio.com/tmp/printdryer/.
There's an overall shot, a shot of the nameplate (it's a Printz Automatic Print Dryer, model Jet, no. 2271.), a shot of the aforementioned knob/screw/roller for apron adjustment, and an attempt at a shot with the side plate removed to show the wing nut/screw assembly that controls the tension on the entry squeege roller assembly (*shrug*) or whatever it's called.
Bear in mind I've still got the apron removed. I've still got to go over the drum with bonami before I replace the apron.
I got Bon Ami powder, applied a small amount to a terry cloth lab towel and cleaned, rinsed with a wet towel, and polished with a dry towel the drum. With lots of cursing (no socket set handy) and exasperation, I managed to pull the apron back on, but it had shrunk in washing/drying, so one side if the top roller was pulled off track a little. At some point, I'll need to fabricate a new apron.
I lowered the tension on the bottom roller bar via the wing nuts as far as it would go.
For a flattening solution, I found a recipe at http://www.binbooks.com/books/photo/...46AF422&orig=1 , but it called for 2oz of gelatin and water to make one quart. The gelatin I had was powdered, so I didn't know how best to to translate that, so I used two of the four packets.
When my test print was done washing, I soaked it in the flattening solution for ten minutes, then ran it though the dryer/glazer.
The result was that the surface texture spotting was greatly reduced, as was the "topological cracking", but the print was still not good enough for customers.
For my next test run, I doubled the amount of gelatin in the water and cranked the tension on the bottom/entry roller way up. My thinking was that the cracking/rings was probably caused by uneven drying, so more gelatin would probably keep the water in the emulsion a bit longer. I thought perhaps spotty surface texture might have been due to bubbles trapped between the emulsion and the drum, so I increased the tension on the entry roller, and I also placed the next test prints on the apron at an angle, thinking that bubbles might be pressed out more easily by the roller that way.
Also, I hung the second test run prints by a corner until dry, then soaked in the flattening solution for 30 minutes before running through the dryer.
The result was prints almost (but not quite) free of "topological cracks" and texture spotting. I'll bet that if I stick to the same procedure, but double the amount of gelatin again, I might be good to go.
I read on photo.net that one person had a good results with Kroger gelatin (what I'm using) in sufficient quantities that he could see it floating in solution.
I've still got to research the impact of glazing on solenium toning. I've heard glazing is bad for toning, but haven't read yet WHICH kind of toning -- all? some?
Just ran some more prints through the dryer but with two boxes (ea. box has four 1/4 oz packets) of gelatin dissolved in one quart of water for a flattening solution. The mottled surface effect is still there. About the only thing I can think of left to try is to add some photo-flo to the solution.
Should I be squeegeeing my prints before I put them on the dryer? I'm putting them on sopping wet. Maybe steam from all the moisture is causing this effect?
I've never had any luck in trying to ferrotype prints. Close, but one or two defects totaly ruin the print. Very frustrating.
Polishing the plate and then squeegeeing the wet print surface directly onto it is what I have heard but my solution was to decide that I really like a plain F surface. Works every time.
well... I'd all but given up trying to get glazing to work with this combination of paper (Ilford MG fiber-based) and dryer. I'd settled on just air-drying and cold-pressing my prints to get something remotely acceptable. I hate to settle.
in the course of a print job, I ran some contact sheets, which I do on single-weight Azo. Just to try something different, I mixed up a bucket of photo flo and dropped the prints in to use it as sort of a wet holding bin as I ran the prints through. The single-weight Azo prints came out nearly perfect. I'd say they would probably have been acceptable for customers, maybe not for exibition, though.
I tried the same thing with my next run of double-weight Ilford MG, and got the same problems again. I like the Ilford paper, I'd rather not switch papers, but there doesn't seem to be a combination of wetting/flattening agent and roller tension that will work suitably with this dryer and this paper. Within the next few weeks, hopefully, I'll find one of those double-sided glazing dryers with adjustable heat and the first thing I'll do is try a combination of lower heat and longer dry time to see if that works.
With the dryer I've got now, the prints nearly always pop off of their own accord within seconds of when they clear the last roller, so I think maybe the drying time is appropriate for this temperature, but I think the entire process is maybe a little to fast for this paper.
I ran across a post from someone, I think on photo.net, that intimated that contemporary papers are probably more challenging to glaze because the emulsions are thinner. I'll bet Azo has undergone comparitively fewer changes in the hundred-odd years it's been in production, and that might be a key to why it works so well.
I'm determined to eventually be able to get a high glaze with all my prints -- at least all the ones small enough to fit on a dyer. Maybe I'll eventually check out waxing.
if someone's got a recommendation for a VC paper with a thicker emulsion, wide tonal range and something that would still work with the Ilford MG filters, I'd be game to try it when my current box runs out.
Just a secondary or third thought...
Are you using hardener in your fix?
Nope. No hardener.
For me, that extra bottle in the rapid-fix kit is just packing. I don't use it with film or paper.