DIY Film Dryer?

[rustyair]

I'm thinking of making a film dryer for 4x5 negatives using two hepa air filters below. One for air in and another one for air out.

http://www.amazon.com/2-Kenmore-HEPA...LQ/ref=lh_ni_t

I would appreciate any advice before I make my move.

[joselsgil]

rustyair,

Is there a reason why you need the film dried with forced air? The reason I ask, is because I just hang my film to dry in an old metal locker. This has been a method of drying my film since I was in high school. In college, we had the forced air with heat, but drying time was important, as you needed to get your film out of the drying cabinet before the class was over. At home, I just develop the film, hang to dry and leave it over night.

An air purifier in the room where you dry your film is a good idea, as it helps to keep the dust under control.

Jose

[jslabovitz]

I made a film dryer recently for roll film (or sheet film developed using the 'taco' method, in a roll-film tank). My only regret is that I didn't build it sooner! It's great to have film that's dry in only half an hour or so.

I'll tell you how I built mine, even though it's for roll film -- maybe it will be helpful. I combined a few ideas I'd read about on various forums (probably APUG). Basically, it's a plastic tube that's set to be vertical. A fan situated at the bottom of the tube draws air from the top, across the film reels, thereby drying the film. By drawing the air in from the top (and across the filter), dust won't be blown into the film. I didn't see any need to put another filter at the exit of the fan, figuring the positive pressure and gravity there would keep dust from entering.

I bought a 4" wide ABS plastic tube (used for drain pipes, I believe) that would be tall enough to fit a few reels (about 10"). Over the top of the tube I put a filter cloth I found in a hardware store. (It turned out to be the wrong type, a fiberglass filter; your HEPA filter is a better idea.) It's secured by just a wide rubber band; nothing fancy.

For the fan, I stopped into a local computer surplus store and bought a 4" diameter fan that would be used in a computer case. It was about $3. I also bought an old wall transformer of the same voltage as the fan (12V, if I recall) and a bit more current than the fan would draw (not much -- way less than an amp). I had to mess around with the connections to figure out which wires from the transformer needed to go to which wires on the fan, but there aren't that many combinations.

I built a little frame out of foamcore and bulldog clips for the fan. It's basically a rectangle slightly bigger than the diameter of the tube, with an inner rectangle cut out, for the air flow to pass through.

To use it, I simply pick up the plastic tube and stack my just-washed reels on top of the fan & its frame. Then I carefully place the tube over the reels. Finally, I turn on the fan. That's it!

The whole thing is set atop some wire-frame shelves above my sink, so there's plenty of ventilation, and any excess water drips into the sink. While some folks have used a heat source (small lamp or coil), I haven't found it necessary, at least in the summer. I figure if I need to, I can just set up a 60W lightbulb above the filter, which will probably be enough to warm up the incoming air.

I hope this makes some sense. I can post some pictures later if you'd like.

--John

[alexn]

Good idea John...

I was planning something like this but I do a lot of E6, so I have to take the film off the reel to stabilize them as the stab is not good for the reels (as I understand it) Once wet, I cant imagine getting the film back onto the reel to dry in this fashion... For B/W 120 reels I will make something like this.. Sounds so simple and very effective... Im so impatient that once I've developed film I want to be able to scan it within an hour or so...

[photobymike]

my 4x5 film dryer.... i use fixer with hardener to help keep dust from embedding in the emulsion. I really do not have a problem with dust

[rustyair]

rustyair,

Is there a reason why you need the film dried with forced air?

Jose

The reasons are pretty simple. No dust and I don't like to wait 3 hours or over night to see the results.

I hope this makes some sense. I can post some pictures later if you'd like.

--John

Yes. Please post some pictures!

[rustyair]

my 4x5 film dryer.... i use fixer with hardener to help keep dust from embedding in the emulsion. I really do not have a problem with dust

I've never heard of using hardener. Can you explain the details?

[photobymike]

Kodak Rapid Fix comes with a separate bottle of acid i believe to add to the fixer mix ... i buy the gallon mix or 2 gal of paper fixer.


http://www.largeformatphotography.in...-what-are-they

When the film is drying the emulsion is soft and really susceptible to scratches. The hardener makes the film more resilient to scratches and dust and lint embedding in the film. After the film dries i wipe with a static cloth and blow off with treated compressed air.

I know there are several film types and developer combinations that do not work well with a hardener with fixer.... But also important is properly mixed photo-flo. Always i use distilled water for chemical mixing.. you would not believe what comes out of the tap. Photo-flo helps the film dry uniformly and may help "sealing" the film protecting it from dust embedding on negs. I really do not have a problem with dust, solved that problem years ago..

[photobymike]

http://www.largeformatphotography.in...754#post939754

Dust buster compressor i am selling

[jslabovitz]

Here are some photos of my quick-and-dirty roll-film dryer. I apologize for the poor quality of the images; there's not much light in my little "lab" area.

1. The dryer as assembled. The black tube is a 4" ABS plastic tube about 10" high. The blue material at the top (held on by a rubber band) is a fiberglass filter. If/when I rebuild this, I will use another filter, like a HEPA filter as suggested above.



2. The base of the dryer. The white board is foamcore cut to a square big enough to hold the base of the ABS tube, with a hole similar to the the diameter of the fan opening itself. The corners are trimmed so I could clip the fan onto the base using bulldog clips. (This would be better as a wood or acrylic platform, with feet to raise the platform above the surface, the fan mounted to the bottom, and some kind of guides to hold the tube in position.)



3. The underside of the base of the dryer. If you're curious, the fan says "Foxconn DC Brushless Fan / 12VDC / 0.14 A".



4. The dryer with film rolls, before the tube is lowered over the rolls, onto the base. There's nothing particular that holds the rolls there; I'm just careful with the process, and it mostly works.



What's not shown is the power transformer, but it's just a simple 12VDC wall-wart type, with current supply greater than what the fan needs. I had to mess around a bit to figure out the connection to the fan; that's all just taped together right now.

Hope these help to visualize the idea and give you some more ideas.

--John