How to make Paints
Paint is defined as a mixture of pigment and binding medium which can be spread to a dry thin film to decorate or protect a surface. |
| Shoe polish |
Raw Materials for Oil Paint
A paint is basically a mixture of the following types of ingredients.Pigment
A pigment gives body and colour to the paint. Pigments can have different colours.Drying oil
A drying oil is a liquid which absorbs oxygen as it dries up. It helps to spread the paint on a surface. Turpentine oil and tung oil or china wood oil are most common drying oils.Thinner
It is used to make the paint to spread easily. Usually petrol, xylol, benzene, turpentine oil, naphtha and rosin spirit are used as thinners.Drying agent
A chemical that speeds up drying. It acts as an oxygen carrier and used in small quantities from 0.5% to 2% of the oil.Mn02, Pb02, PbO are the common driers used. They accelerate the drying of the film through oxidation. Paints containing lead are dangerous because they flake off and mix with dust. This is particularly a problem in homes where the paint is old.Fillers:
China clay or BaS04 are added to the pigments to increase their durability .Making of Paints
Paint making is a matter of dispersing pigments in liquids like resins and solvents. For oil based paints, the dispersion of the pigments in the liquid is done by grinding them together. The dry material with some oil are added to the ball mill which is then rotated for hours. The grinding action of the balls against each other produces a smooth dispersion of the paint. The paint is then filtered to remove any coarse particles. The final products is packed in metal canes. Water paints or Distempers These are water paints containing pigments like ZnO, glue and resin. A good paint should resist the effects of light and heat. It should resist the action of acids, alkalies and the atmospheric oxygen. It should not be affected by the atmospheric changes such as rain and seasonal temperature variation.How to make Varnish
Varnish is a colloidal solution used to protect and decorate wood surfaces. It dries by evaporation, oxidation and polymerization.Raw Materials of varnish
One part Hard dark amber gum China wood oil Parts Linseed oil Two Parts Spirit seven Parts Preparation of Varnish Amber gum is heated to a temperature of 650°C in an iron kettle. It is then cooled to 500°C and china wood oil is added. The mixture is again heated to 560°C and linseed oil is added. It is cooled to room temperature and spirit is added. This varnish will dry to touch in about 4 hours and hard in about 8 hours. Varnish differs from paints in the sense that varnish does not contain plastisizers and pigments. Spirit varnishes are those in which a volatile liquid such as alcohol is used as a solvent for the resin.How to make Polish
Generally black and dark brown shoe polishes are used for the protection of shoes from water and weather. Table Constituents of Dark Brown Polish 1 Bismarck Brown 15% 2 Pearl Ash (Potassium Carbonate) 57.5% 3 Turpentine Oil 17.5% 4 Palm Oil or Soap 10% 5 Optical Brightner As required Pure Bee's Wax It maintains the softness and shine in the polish.CarnaubaWax
It prevents the extra softness of the shoe polish and gives it proper hardness.Turpentine Oil
It keeps the softness of shoe polish and prevents it from drying. More over it helps in the absorption of shoe polish in leather.Preparation of Shoe Polish
Pure bee's wax is heated slowly on a water-bath. As soon as it is melted turpentine oil is added to it. The mixture is homogenized and cooled with stirring. Caustic soda is heated in a minimum quantity of water to make a lye. This lye is added to the above mixture with vigorous stirring.When it becomes thick nigrosine oil is added to it and stirring continued till it gains the desired thickness. In case of dark brown polish, a concentrated solution of bismarck brown, and pearl ash (potassium carbonate) is prepared in water and other components are added with stirring. Shoe polish is covered with a thin foil of zinc or aluminium to prevent any loss of turpentine oil.
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