Homemade film and print drying cabinet

Robert

New Member
Registered User
I have built a drying cabinet for my darkroom and thought it might be of interest to others on this forum.

When setting up the darkroom I looked into buying a professional Marrutt film drying cabinet and an Ilford print dryer like the 1050 RC I have used at Photofusion in Brixton. The film drying cabinets I found on eBay were very expensive and mostly in quite poor condition. The Ilford print dryers are great bits of kit but as they are no longer manufactured, are hard to find in any condition and hence very expensive on the second hand market.

A simple and cost effective solution has come in the form of a modified Ikea steel locker called "IVAR". This is about 80cm wide x 83 cm high and costs about £65.

The modifications involve the addition of a heating, ventilation and a film/paper hanging setup.

Heating is provided by two 80W tubular electric heaters mounted in the base and wired through an insulated connector block, combining an earth connection to the cabinet, into a single three pin mains plug fused at 3A.

A 3in diameter extractor fan is mounted in a circular hole cut into the top of the cabinet. This 5V fan is from an old PC power supply and is wired to a surplus USB cable connected a 1A mobile mains phone power supply. The fan sucks filtered air through two 4in square inlet grills at the bottom of each side panel. These grills are also designed for PCs and were bought from RS Components for a few pounds. The holes in the top and sides were cut using an air compressor powered Nibbler but these could also be cut out using simple hand tools.

At an ambient temperature of 20C the heating and ventilation system maintains a constant temperature of about 30C inside the cabinet. These 5V fans are typically rated at about 30 cubic feet per minute so a very rough estimate is that the cabinet air is changing 3-4 times per minute. Were the fan to stop running for some reason the internal temperature would only rise to about 33C because the hot air escapes through the fan aperture by convection. The cabinet is protected from possible over heating by thermal cut-outs built into the heaters.

To hang film and prints I fitted three 10mm diameter stainless steel tubes as hanging rails. The stainless steel tubes are a bit of overkill but were available as leftovers from another project. Hardwood dowel rods would be quite sufficient. I bought some plastic clothes hangers on eBay and modified them to have a hook, made from 3mm aluminium wire, above each of the two clips which have soft rubber inserts in the jaws and are great for hanging sheet film and paper. I use a combination of Paterson film hanging clips and bulldog type clips for roll film.

A battery powered LED light is attached by a magnet inside the top of the cabinet. This is very handy for hanging and inspecting prints when the safelights are on and you don't want to turn on the main darkroom lights.

To control dust ingress I have attempted to make the cabinet as air-tight as possible so that the only air entering the cabinet passes through the filtered side vents. The doors are sealed using a self-adhesive foam draught excluder and the front vents on the doors are covered on the inside with a strip of masking tape. I always spray the interior surfaces of the cabinet with a fine mist of water before hanging film up to dry.

I am now able to dry roll and sheet film in about 1 hour. For paper I have found that using a squeegee to remove surface water from both sides of RC prints reduces the drying time to about 15 min. I would estimate that fibre paper will require at least 2 hours in this dryer. Roll films have to be cut to fit the height of the cabinet. This is less than ideal as wet film is very difficult to handle safely but I now have a simple and safe method for doing this without damaging the film. For 120 roll film this involves clipping both ends of the roll to the rail and then cutting carefully at the mid point using sharp scissors. I then attach bulldog type clips to the side edges of the film at the bottom of each strip to stop them from curling up during the drying process. I remove these temporarily about 15 mins into the drying time and gently mop up any surplus water that collects around the clips with a tissue.

I am very pleased with the performance of this cabinet which has exceeded my expectations. It is quite compact and relatively easy and cheap to build. I would think that the total cost would be less that £150. By combining film and print drying into one box it is ideal for a small low volume hobbyist darkroom. It is easily big enough to dry up to 16x20in prints which are the largest I can produce in my darkroom. I hope the following photos are self explanatory. I will be very happy to answer any questions.
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mpirie

Member
Registered User
Very nice Robert!

Just goes to show what can be done with some time and ingenuity!

Welcome to the forum by the way!

Mike
 
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