Home Movies (1944)

HOME MOVIES FOR APRIL I, IT is just as important to carefully dry the film thoroughly after home processing as it is to wash it. Last month, I discussed an advanced method of washing processed motion picture film and a novel means for insuring accurate temperature control of the wash water. And now that we have seen the wisdom of being fussy about washing our film, it certainly doesn't follow that we should be careless about drying it. Let us assume that our class of home film processors, which we hope is avidly following this series of articles on home processing methods, has completed the final washing of the film. An examination of both surfaces will reveal hundreds of tiny droplets of water adhering thereto. Should any of them remain to evaporate away on the film, they will leave an objectionable stain. The problem, then, is to remove these drops as the film is wound from the processing rack to the drying reel. A common method for removing residue water from processed films is to hold two pieces of chamois or viscose sponge together, allowing the wet film to pass between the two, and squeezing gently so that the pressure removes the moisture by absorption. This is a satisfactory method, but presents certain objections which the automatic film wiper about to be described here overcomes. Dust, dirt and grime are bound to accumulate on the surfaces of the viscose sponges or chamois used in the above method, resulting in scratching the film. The chief difference between the automatic film wiper and the hand drying method is that the absorbtion of residue water is achieved by a gentle rolling pressure of two sponges instead of by friction. Thus the water is squeezed and absorbed as the sponges revolve over (FJ 3racket (S) 3/8" Pipe • Water is removed from both surfaces of film simultaneously by this ingenious device as film is being transferred from processing reel to drying rack. SPOTLESS DMIIG OF PROCESSED FILMS... B y ARTHUR M . SHARP the film's surface, practically eliminating any chance of film scratch. This film wiper, incidentally, serves a dual purpose: besides removing moisture from the film, it also guides the film upon the drying reel, automatically spacing it as it is wound. Here, readers are referred to the article in the February, 1944, issue of Home Movies (Pg. 62) wherein was described an automatic reel winding guide consisting of a threaded carrier rod and a guide spool which moved across the length of processing or drying rack, automatically laying the loops of film upon it properly spaced. The automatic film wiper, pictured at top of page, operates on the same principle. It consists of a metal bracket supporting two discs to which are attached circular sponges. The top disc is guided along the carrier shaft, as the film is wound upon the drying reel. The wet film, unwinding from the processing reel, is threaded between the two circular sponges and passes on to the drying reel above. The emulsion side of the film is dried by the lower sponge and the celluloid side by the sponge above. In passing on to the drying reel, the film presses against the upper • Continued on Page 162 • Diagram at left gives details for constructing the rotary sponge film wiper. Picture below shows overhead drying rack enclosed by cheesecloth hood to provide dustless compartme i4" h 4*f**^ 151