Set up a home laboratory is not difficult, but some security procediementos must be observed. Chemical, especially fixer, exude toxic fumes which demands a constant exchange of air in the workplace , by placing hoods or frequent door openings and/or the room windows. It is crucial to prevent chemicals have eye contact. Hands and clothes can be protected by aprons, gloves and bamboo or metal handles.
One of the golden rules of any laboratory is to separate the dry part (magnifiers and guillotines to cut paper) the wet part (trays with chemicals and wash). The site should be completely sheltered from the light and lit only by red safety lights that do not sensitize the photo paper.
Black & White laboratory
Building safety lanterns
Use a can, for example fruitcake, and drill a hole in the back through a wire with jack and interrruptor. Inside, connect the wire to the lamp socket and screw it one incandescent lamp max 40W, preferably red. In the open part of the can, hold a folded four times red cellophane (eight layers) to filter the light and do not expose the photo paper. 220V lamps used in current 110v become weaker and are good choice when laboratory conditions require that are closest to the area of disclosure and handling of photo paper and at a safe distance from cellophane to not melt it.
Turn negatives into positives
A reinforced cardboard box, covered with white inside and measuring 70 cm high and 30x30cm base, can be used with light source for positivization the negative by contact on photo paper. A milky bulb attached to the top of the box can be connected to a wired switch, which makes the function of controlling the exposure time.
To make positive a picture, put the exposed photo (negative) on a blank photo paper and press with a glass. Experiment to set the exact time the amplifier should be connected. After exposure, do the traditional chemical development of the image, now positive .
Processing black & white photographic paper
To develop the role we need four trays arranged in line. At first, immerse the sheet of photo paper in the developer chemical, gently shaking the pan for 90 seconds and seeing the image appear. Take a photo with tongs and drain, going to the next tray (switch) where the image should remain for 45 seconds. Finally again hold the paper with the tongs, let it drain and put in the bath fixer for 120 seconds (resin-coated papers). To eliminate the chemical, wash the pictures of water for 180 seconds, leaving dry in the shade.
Very important: do not mix the clamps or chemicals, as this could unusable them or reduce its useful life.
Suggested materials: four plastic trays and four bamboo tweezers with plastic tips; a photographic paper or envelope Ilford Kentmere RC (glossy/matte/pearl), size 18x24 or 20x25cm; the three basic chemical: the developer and fixer industrially made by Kodak/Ilford marks and the switch can be prepared by diluting 20 grams of citric acid in one liter of water (liquid acetic acid also works, but is more aggressive and smells strong). A clock to mark the time to string a clothesline and preachers to dry the photos.
Where to buy
Chemicals and photographic materials can be purchased at Conselheiro Crispiniano St., Sete de Abril St. and area, in downtown São Paulo (Anhangabau Subway Station).
Look around to find the best prices!