Darkroom Ventilation & temporary blacking out

Hi,

I'm currently building a darkroom in our laundry room, 3Mx2.5M.

The house we're living in is rented, so I'm creating a temporary darkroom and cannot attatch items to wall/ceiling nor mark the walls in anyway.

I'm unsure quite how to ventilate the room safely.

I'm setting up dry side on back wall and wet side on front wall by sink. On left hand wall there's a door and a slat window. The sink is by on the left by the window. On the right is a sliding door to enter/exit the room.

On the wet side in the middle at the bottom of the wall is a removable board that goes through to the area under the house. There is a duct from an existing dryer through the board.

I have looked into ventilation and found an extraction fan kit for $70 NZD that appears to be the best so far. I'm not wanting to spend too much.

Is it possible to have some kind of fan mounted in a board over the slatted window that would extract the fumes or would it be better to have the extraction fan mounted at the top of the wall above the printing trays?

Is there anyway of light proofing the fan from the front, covered in black material or will that reduce the efficiency of the fan?

Is using the existing duct with a bit of modification a good idea? Or do I risk fumes getting into the rest of the house?

Any ideas on how best to cover the door and window and the sliding door temporarily so it can be removed when we move? And doesn't mark paintwork etc?

Thought of covering windows with wooden panels pushed into place, then thick black plastic over it. Could always attach things with gaffa tape then repaint it when we move.

All replies and information much appreciated,

Cheers Leo

One other question; Drying films

Do i need a negative dryer? Or can I just hang them in the darkroom?

One idea was to build a wooden cupboard and use computer fans, 2 sucking air in from outside and 2 on the inside extracting air out, so to have a constant flow or cool air assisting the drying. Would I need some kind of filter to rmove dust?

Cheers Leo

tek,
You should be able to vent through the window. Just build a box to cover the window. If you need a light trap you could use an aluminized dryer vent & run it in a "U" or "S" shape to act as a trap.
You may have to paint the innards black.
If you're using fans to dry film , yes, you should filter the incoming air.
I just use what is basically a large garment bag.

You should be able to get Duvetyne from expendables supply shops. It seems like there are quite a few film productions going on there so there may also be rental houses and expendable shops around. Ask them for scraps or you may be able to buy it by the meter. It's black lightproof fabric like felt. Hang a piece over the inside and outside of your door and that should work. That's what i have in my apartment. I also made a fan enclosure with black foam cor that keeps light out but still removes the fumes. Try oderless stop and fixer as well.

Hi, There is a material sold in some fabric stores here in the u.s. available in rolls that is referred to as blackout cloth (I think. If you ask around someone should know what you're looking for.) It's a thick white fabric that has the feel of rough canvass on one side, and is vinyl or rubber on the other. For my darkroom I use this material to cover two windows and a doorway (frame only, no door) attached with velcro. I have velcro running along the frame of each window and the doorway with the corresponding velcro attached to the fabric. So, the cloth overlaps and is parallel to the windows. The cloth over the doorway I put up/ take down every session. Using a board inside the window frame would create a better baffle in addition to the cloth. But, before you cut wood consider using black foamboard cut to size. Moves in and out easily and is cheaper. Is this confusing ? probably so, I feel like I'm blabbering. Anyway, this is what I would suggest for blacking out a room without altering it's structure. You may have to repaint where you applied the velcro.
For ventilation, in my own darkrooms I've used bathroom exhaust fans that I've installed in the ceiling. The duct was then bent into two 90 degree angles (not exactly, but s shaped as already mentioned and spray painted a flat black). In your case, I would be inclined to adapt a fan for use in the existing hole for the dryer exhaust. Ideal placement is nice, but the important thing is circulation. If that's not possible then I would adapt a system for the window. You may be able to find an official darkroom exhaust fan on *bay, or a defunct lab. This would make the job easier.
As far as a film dryer I guess that depends on your volume, or how refined you would like to be. Hanging film over a bathtub or in a shower stall and then closing the bathroom door is sufficient if you don't mind the inconvenience. You can even buy a retractible 'travel' clothesline that has suction cups at either end that are perfect for this. I have a mini dryer that was sold commercially; basically it consists of a thick vinyl bag, electric heating fan, filter, and wall mount. With a little creativity you can make your own. You may even be able to find someone getting rid of a commercial film cabinet dryer.
Good luck! cameron

In the short time that I have been developing film, in all the literature I have read, it is never stressed how important it is to dry film in a 'DUST FREE' enviroment. Dust free really does mean what it says. Don't be fooled in to thinking that hanging the film in a disused room thats not been entered for a few hours will be a sure-fire way to beat the dust, it won't.

There are many good ideas in past threads on APUG. Just do a search. I also use the cheap zip up garment hanger as already mentioned.

Regards

Stoo

If the doors and window have a metal frame, black plastic could be taped over them with no permanent damage. In the USA farm and garden stores have a variety of black plastic. Some of it may require two layers. Perhaps sheet metal hooks can be made to hook behind the frame above the doors and window to support a curtain rod and black plastic curtain to block remaining leaks.

I'd try using the drier vent first. If that pollutes the house, then you can work on the problem again. Remember, if you exhaust fumes, you need an inlet for clean air.

Keeping the darkroom as clean as possible may make it a good place to dry film. Don't run the exhaust fan while doing this. Film driers made like a garment bag sound like a good idea, but drying film on the reels may be easier. If you can perfectly filter air, a computer fan will push enough air past the film. A 4" plastic tube supports the reels and channels the clean air. Commercial units like this are available, but a similar drier should be easy to improvise.

Just to add a few notes….before you get your exhaust fan running, cover your tray with fixer with a cardboard (or similar) and open it only when you slide your print inside. It cuts on fumes a lot. Also, if you use a stop bath, buy odorless one. That helps too.

As for drying the film….just hang it with a little weight on the bottom and leave the room quietly. No fans are necessary. It will just spread the dust around….

Metod

I second the blackout cloth. I tried various plastics for years and was never satisfied with the results. Blackout cloth solved my problems.

I didn't know what to call the stuff, so I went to a fabric store and asked for the material used to line drapes. I got just what I needed.

How long do you stay in the darkroom in a session? I have to use my small bathroom and have no way to ventilate. I just stop every half hour or so and open the door for a few minutes. I don't notice any significant amount of fumes.

juan

You say there is a duct under your wet area. If the underside of your house is well-ventilated I don't believe that you will be running any extra risk of fumes re-entering the house than if you vented from the window.
You need a way to draw the fumes away from yourself and a vent low down under or behind your wet area is ideal for that purpose. If you cannot place your fan to achieve this then you should run a duct from your fan to behind your trays in your wet area. You can buy short lengths of air-conditioning aluminium duct from some hardware outlets. You will need to remove the fibre-glass insulation from this duct material because of dust concerns.