How to Make a Photo Developing Sink
Many amateur photographers are obliged to do their developing in odd corners and under conditions which render the hobby somewhat irksome if a large number of plates have to be treated. The main difficulty is to secure an adequate water supply and to dispose of the waste water.
At a small expenditure of money and energy it is easy, however, to rig up a contrivance which, if it does not afford the conveniences of a properly equipped dark room, is in advance of the jug-andbasin arrangement with which one might otherwise have to be content. A strong point in favour of the subject of this chapter is that it can be moved without any trouble if the photographer has to change his quarters.
Fig. 11. -- A home-made developing sink for the darkroom.
The foundation, so to speak, of the developing sink is a common wooden washstand of the kind which has a circular hole in the top to hold the basin. A secondhand article of this sort can be purchased for a shilling or two. A thoroughly sound specimen should be selected, even if it is not the cheapest offered, especial attention being paid to its general rigidity and the good condition of the boards surrounding the basin shelf. The area of the top is generally about 20 by 15 inches; but if a stand of larger dimensions can be found, choose it by preference.
The general design of the sink and its equipment is shown in Fig. 11. For the uprights, which rest on the beading of the washstand, use two boards 9 inches wide, 1/2 inch (actual) thick, and 36 inches long. The top shelf, to carry the pail or other water container, should be of 1-inch stuff; and the two lower shelves be not more than 5 inches wide and 3/4 inch thick. Space the shelves at least 11 inches apart, so that they may accommodate tall bottles. The superstructure will gain in rigidity if the intermediate shelves are screwed to the uprights, in addition to being supported on ledges as indicated; and if the back is boarded over for at least half its height, there will be no danger of sideways collapse, when a full bucket is put in position.
The top of the washstand, on which the developing will be done, must be provided with a tray of lead or zinc. Lead is preferable, as lying flatter; but the jointing at the corners is more difficult than the soldering of sheet zinc, which, though more liable to chemical corrosion, is much lighter than the thinnest lead--weighing about 1-1/2 lbs. to the square foot--that could well be used. If lead is selected, the services of a plumber had better be secured, if the reader has had no experience in "wiping a joint."
A zinc tray is prepared by cutting out of a single sheet a piece of the shape shown in Fig. 12. The dimensions between the bending lines (dotted) are 1/8 inch less in both directions than those of the shelf.
FIG. 12. -- Showing how the tray for sink is marked out.
The turn-ups a, a, b, b, should not be less than 1-1/2 inches wide. Allow half an inch at each end of b b for the turnover c. Turn a a up first, then b b, and finally bend c c round the back of a a, to which they are soldered. A drop of solder will be needed in each corner to make it water-tight. When turning up a side use a piece of square-cornered metal or wood as mould, and make the angles as clean as possible, especially near the joints.
A drain hole, an inch or so in diameter, is cut in the centre of the tray. To prevent the hands being injured by the tray, the front should be covered by a 1/2-inch strip of zinc doubled lengthwise, or be made a bit deeper than 1-1/2 inches in the first instance and turned over on itself.
Before the tray is put in position the basin hole must be filled in, except for an opening to take the waste pipe. The plug is pad-sawed out of wood of the same thickness as the top, to which it is attached by crossbars on the under side. The whole of the woodwork, or at least those parts which are most likely to get wetted, should then be given a coat or two of paint.
A waste pipe, somewhat larger than the drain hole and 3 inches long, having been firmly soldered to the tray, beat the edges of the hole down into the pipe. Then prepare a wooden collar to fit the pipe outside, and drill a hole on the centre line to take a carpenter's screw. If the edges of the tray are supported on slats 3/16 to 1/4 inch thick, and its centre is kept in contact with the wood by the collar pressing against the underside of the shelf, any water will naturally gravitate to the centre and escape by the waste pipe. This automatic clearance of "slops" is a very desirable feature of a developing sink.
To prevent water splashing on to the sides of the stand and working down between tray and wood, tack pieces of American cloth on the sides with their edges overlapping the tray edges by an inch or so.
A small two-handled bath is the most convenient receptacle for the waste water. It should hold at least a quarter as much again as the water tank, so as to avoid any danger of overfilling. A piece of old cycle tyre tubing, tied to the waste pipe and long enough to reach below the edge of the bath, will prevent splashing--which, when chemicals are being poured away, might prove disastrous to light-coloured clothes.
The supply pipe has a siphon-piece of " compo" tubing at the top, to draw off the water when the tube has been filled by suction, and a small tap at the bottom. This tap, when not in use, should be held back out of the way by a wire hook attached to the lowest of the upper shelves. A piece of linoleum should be cut to fit the bath-shelf and protect the drawer below.
List of Chapters in this book: Sawing Trestle | Joiner's Bench | Bookstand | House Ladder | Developing Sink | Poultry House | Bicycle Shed | Rifle Target | Cabinet Making | Telegraphic Apparatus | Electric Motor | Alarm Clock | Model Railway | Reciprocating Engine | Slide Valve Engine | Model Steam Turbine | Steam Tops | Model Boilers | Quick Boiling Kettle | Hot Air Engine | Water Motor | Model Pumps | Kites | Paper Gliders | Model Aeroplane | Scientific Apparatus | Rain Gauge | Wind Vanes | Strength Tester | Harmonographs | Automatic Matchbox | Wooden Workbox | Wrestling Puppets | Double Bellows | Pantograph | Silhouette Drawing Machine | Signalling Lamp | Miniature Gasworks