Drying gelatin silver prints.

[Erik van Straten]

Recently, I bought a Seal Compress 110, a small version (30x40cm) of their adhesive presses. This little machine solves all drying problems that can raise with photographic fiber base baryt paper with a hardened gelatine layer.

I will tell you my workflow when drying wet prints. This is valid only for Adox MCC 110, as Ilford Multigrade has no hardened gelatin layer. Ilford Multigrade FB will not stand hot drying.

When the prints are fixed, I rinse them in water of 20 degrees C for about half an hour. To rinse in cold water makes no sense. Then I dry them on my Büscher drying press 50X60cm. That is an old photo dryer of the type that was generally in use until the eighties. In fact it is a hot drum. They are still being made, but at a formidable price. I connect this machine to a digital thermostate with the name "H Tronic". I've found out that the best drying temperature is 40 degrees C. The thermostate is coupled via a sensor to the drying machine, so it is kept at 40 degrees C all the time. This is very important. Also important is the drying time, in the case of the paper I use it is 30 minutes. This must be kept scrupulous. If the photo is too short on the dryer, it still contains humidity and it wil corrugate immediatly when taken from the press. If the picture is too long on the press, it will wrinkle.

If the above is done well, at first everything looks fine, but after a few hours the photo will loose its flatness and corrugates. It absorbs humidity from the air I guess. This is where the Seal comes in. The Seal press has a built in thermostate. The maximum temperature is 175 degrees C. However, for my goal it must be around 80 degrees C, quite low for this machine (it is in fact a gluing press). The print is then put between two clean pieces of paper and put into the Seal for 30 seconds. When the picture is taken out, it is hot, and must be cooled immediatly under a flat object. Then it is is flat, and it stays flat! A miracle.

Erik.

 

[x-ray]

Erik there no problem drying unhardened prints on a hot dryer. I dried thousands of prints on various brands of fiber based paper on the floor model Pako and Arkay tabletop dryers I've owned with no problems. I've even ferotyped unhardened prints on a Pako commercial dryer. No problems doing this provided you keep the temp at 200 F or slightly lower. You just don't want to boil the moisture out

I always used a release / flatening agent like Pakosol when glossing FB prints. It makes a perfect super high gloss and helps keep the print flat.

I typically air dry my SG FB prints now and flatten them in my seal press. I run the press around 200F or slightly less. About 30 sec to 1 min is all that's needed. I use a release paper over the front of the print between the print face and the hot platten. In this case it just help preventing tiny dents in the print if there's a speck of dirt or lint on the platten. Under pressure a speck of dust can cause a small imperfection in the surface. Under the print I use a 4 play acid free rag board. It's not required but I've done it this way for decades.

I have a stash of Kodak drymount tissue in rolls that I've used out of for forty years and use Seal color mount for color and digital prints which is relatively low temp compared to the Kodak.

A little hint on keeping prints flat when they come off the hot dryer (200f) or drymount press. Flatening agents are good but no longer made. You can however find formulas and mix your own. It's been a while since mixing any but it contains alcohol, glycerine and wetting agent.

If you don't want to use that, simply take the print from the dryer (200f) or press and lay it on a counter face up with no prints overlapping. In ten minutes at so they'll be flat. When moisture in the print reaches equilibrium with the surroundings they'll flatten. If I have a quantity of pro ts to flatten I make sure the floor is clean and just toll them face up on the floor. Works perfect.

Years ago you could buy a print flatening machine. It was nothing more than two mesh belts close together so as to sandwich a print and would transport the print via a motor over a metal tray of simmering water. The back of the print would absorb moisture quickly and pop out perfectly flat in a few seconds.

 

[Erik van Straten]

Thank you x-ray for this write-up. Very interesting and helpful.

It is not my goal to make very glossy prints, I like glossy paper dried matte.

I've never heard anything about Pako and Arkay dryers, but that must be the difference between Europe and the US.

Great to read that your flattening in the Seal is almost exactly as I do it. Yes, it is very important to keep the platten clean and to put the print between super clean pieces of paper. A tiny piece of dust will cause a mark in the gelatin.

Ilford warns for using hot dryers for their FB paper. Adox on the contrary gives some useful tips.

When I take my hot print from the Seal, I just lay it on the floor and put a thin sheet of metal over it until it is cold.

Thanks again!


Erik.

 

[x-ray]

I use a seal release paper over my prints. I think it's still made and comes in rolls. If you take care of it a piece will last a long time. It has a no stick coating on one side and keeps goo off the platten when drymounting. It also keeps it off the print. It's acid free which is a plus.

Dents from dust and trash can ruin prints in the press. I often use a small air compressor to blow dust out of the press and off the print.

There's a Pako super drum print dryer on eBay right now that'll give you an idea of what I'm talking about. These were made by Arkay and Pako and we're in every commercial lab I worked in including my studio. The one on the bay is missing parts but gives an idea and is a medium size floor model. They were also made in smaller tabletop models which I owned one of too. When I worked for Union Carbide nuclear in the mid 70's we has two like the one pictured and a large one with a 6' stainless drum that was heated with hot water heater by a gas flame. With the hot water unit you never needed to worry about it getting too hot. On the electrically heated units you wanted to be sure to keep the drum temp under 210 f so as not to fry the print. I've seen the temp run up high enough on these to scorch the print. Sometimes the print would stick to the drum and have to be soaked off with water being careful not to damage the chrome surface.

Arkay, Beseler and Pako made nice tabletop 16" wide machines with chrome on stainless drums. In the days before RC based correctly prints we dried FB color prints on them. There are some tabletop drum machines on eBay also.

These big units had a chrome surface drum designed to make a perfect super high gloss. A high gloss print is gorgeous.

 

[Erik van Straten]

O yes, that Pako is a wonderful looking machine, but I've no idea how it works! I've never seen one before, in Europe they are unknown afaik.

Yes a high gloss print can of course be very beautiful, but this very much depends on the character of the print imo.

I will take care of my Seal, it is really a very useful device. I will see if I can get a small air compressor.

Thank you x-ray for this interesting info.


Erik.

 

[x-ray]

I purchased my compressor at Home Depot for something like $70 several years ago. It handy to blow dust off negs in the negative carrier before inserting in the enlarger. Just set the pressure very low. They can be a little noisy however. I also use it when framing prints to make sure there's no dust inside the frame. Also if you shoot large format it's perfect to blow dust out of the holders especially the light traps where the dark side goes in. It's amazing how much dust collects in holders.