In the application of paraffin for waterproofing purposes it is first melted along with the requisite quantity of drying oil and cast into blocks. This composition can then be applied to fabrics by rubbing them over with a block of it, either cold or gently warmed, or the mixture may be melted and laid on with a brush, the complete impregnation being effected by subsequently passing it between hot rollers. When this paraffin mixture has been applied to cloth such as that employed for blinds or tents, it renders it very repellant to water, although still pervious to air.
Cloth paraffined in this manner forms an excellent basis for such articles as capes, tarpaulins, &c., which require to be rendered quite impervious by subsequently coating them with drying oil, the paraffin in a great measure preventing the well-known injurious effect of drying oil on the fibre of the cloth. The paraffin mixture can also be advantageously applied to the various kinds of leather. One of the most convenient ways of effecting this is to coat the skins or manufactured articles, such as boots, shoes, harness, pump-buckets, &c., with the melted composition, and then to gently heat the articles until it is entirely absorbed. When leather is impregnated with the mixture, it is not only rendered perfectly waterproof, but also stronger and more durable. The beneficial effects of this process are peculiarly observable in the case of boots and shoes, which it renders very firm without
destroying their elasticity. It therefore not only makes them exceedingly durable, but possesses an advantage over ordinary dabbing in not interfering with the polish of these articles, which, on the whole, it rather improves.
The superiority of paraffin over most other materials for some kinds of waterproofing consists in its comparative cheapness, in being easily applied, and in not materially altering the colour of fabrics, which in the case of light shades and white cloth is of very considerable importance.
8. A waterproof packing cloth which does not break may be made by covering the fabric with the following varnish:—2 lbs. of soft (potash) soap is dissolved in water and mixed with an aqueous solution of sulphate of iron. The washed and dried soap is dissolved in 3 lbs. of linseed oil, in which 1⁄5 lb. of caoutchouc has been previously dissolved.
WATERPROOF LIQUID. Prep. 1. India rubber, in fragments, 1 oz.; boiled oil, 1 pint; dissolve by heat, carefully applied, then stir in of hot boiled oil, 1 pint, and remove the vessel from the fire.
2. Boiled oil, 1 pint; beeswax and yellow resin, of each 2 oz.; melt them together.
3. Salad oil, 1 pint; mutton suet, 1⁄4 lb.; white wax and spermaceti, of each 1 oz.; as the last. For ‘ladies’ work.’
4. Bisulphide of carbon, 2 oz.; gutta percha, 1⁄2 oz.; asphaltum, 2 oz.; brown amber, 1⁄2 oz.; linseed oil, 1 oz. Mix. Dissolve the gutta percha in the bisulphide of carbon, the asphalte and amber in the oil, and mix well.
Obs. The above are used for boots, shoes, harness, leather straps, leather trunks, &c., applied warm before the fire.