SURFACE FINISHING

摘要

1528246 Laminates NATIONAL AERONAUTICS & SPACE ADMINISTRATION 8 April 1976 [16 April 1975] 14423/76 Heading B5N [Also in Division B7] A surface, e.g. of an aircraft or boat, having irregularities and/or concave deviations from a smooth configuration is given a smooth finish by applying to at least a portion of the surface a layer of fluid adhesive, covering the adhesive with a sheet of flexible film material whose thickness is 7À62 x 10-2 cm. or less, the film being under tension and the tension being maintained during setting of the adhesive so that the tensioned film is bonded to the surface by the adhesive. The film which may be coloured may be of polyimide, polyester, nylon, polyvinylidene chloride, polyvinyl acetate, polyvinyl chloride, polyethylene or polypropylene, and the adhesive may be a polyurethane. In Fig. 1 the wing 10 of a glider comprising I-beams 12, 14, 16 covered with aluminium skin 18 having surface irregularities at seams between the segments of the skin and at the recessed rivets, is coated with adhesive 36 and covered with transparent film 38 under tension. Pressure may be applied to the film material using hard plastic squeegee 40. Preferably with a sheet of protective material interposed loosely between the film and squeegee. Tension may be applied to the film by pulling edges 42 and 44 held in a frame having clamp assemblies mounted thereon. When a segment of film material is applied to the wing the blunt edges of the film may be smoothly finished either by spreading a filler adjacent the blunt edge which after hardening is sanded to form a smooth tapered edge or by sanding the film and adhesive to form a smooth tapered edge. The film may be used to cover heating wires used in deicing which are incorporated into an adhesive layer on the surface.