Paint,varnish,distemper
- 1. BMC Material Study: Paints, Distempers & Varnishes Group 5 - Abbin Saju, Aiswarya Padmakumar, Aksa Clare Cleetus, Akshay Prasannan, M. S. Fayizajahan, Melvin Joshy, N. N. Abhijith, Renetta Roshan
- 2. Paints Paints are coatings of fluid materials and they are applied over the surface of timber, metals and plastered surfaces.
- 3. The need for painting: ● It protects the surface from weathering effects of the atmosphere and actions by other liquids, fumes and gases. ● It prevents decay of wood and corrosion in metal. ● It is used to give good appearance to the surface. The decorative effects may be created by painting and the surface becomes hygienically good, clean, colourful and attractive. ● It provides a smooth surface for easy cleaning.
- 4. Ingredients of Paint 1. Bases: A solid substance in a fine state of division and it forms the bulk of a paint. It determines the character of the paint and imparts durability to the surface which is painted. It reduces shrinkage cracks which are formed on drying. 2. Vehicle / Carrier: The liquid substance which holds the ingredients of a paint in liquid suspension. They make it possible the even spreading of paint in the form of thin layer and also acts as a binder.
- 5. 3. Drier: Substances that accelerate the process of drying. A drier absorbs oxygen from the air and transfers it to the linseed oil, which in turn, gets harder. 4. Colouring Pigment: When it is desired to have a different colour than the base of the paint, a colouring pigment is to be added. The pigments are available in the form of fine powders in various colours and qualities. Ingredients of Paint
- 6. Ingredients of Paint 5. Solvents: The function of a solvent is to make the paint thin so that it can be easily applied on the surface. It also helps the paint in penetrating through the porous surfaces.
- 7. Manufacturing Procedure The ready-mixed paints of different make and various brands are available in the market.
- 8. When exposed to atmosphere for a long time it becomes stiff. Stiff paints can be recovered into usable paint using the following steps: (i) The sufficient stiff paint is taken in a pot. The remaining stiff paint is to be covered or left with a layer of linseed oil. (ii) The linseed oil which may either be raw or boiled or pale is then mixed with stiff paint by a stick. (iii) The other ingredients of paint are then added. (iv) If a colour is required, suitable pigment is added and thoroughly mixed. (v) A second pot is taken and it is covered with a canvass which is tied tightly. (vi) The mixed paint is then allowed to pass through the canvass of second pot. The brushes may be used for this purpose. (vii) The paint is then ready for use. The mixed paint may be prevented from drying by maintaining a thin film of linseed oil or of water at top.
- 9. ● It should have good spreading capacity . ● It should be economical . ● It should be easily applicable . ● It should dry in reasonable time. ● The paint should form a hard and durable surface. ● It should not be affected by weathering actions. ● It should give an attractive and pleasing appearance to the surface . ● The painted surface should not show any crack . ● The paint applied should form a thin film of uniform nature. Characteristics
- 10. Physical properties of Paint ● Heat stability. In outdoor applications, the durability of a pigment is not solely dependent upon its fade resistance in sunlight. ● Lightfastness. The lightfastness of a paint or pigment describes how well it withstands degradation from UV light. ● Opacity or Hiding Power. Hiding power or opacity of a paint or pigment is its ability to hide the surface that you are painting. ● Color Temperature. Different pigments of the same hue can exhibit varying color temperatures. ● Tinting Strength. Tinting strength describes the ability of a pigment to change the hue of another color.
- 11. Types of paint & their usesOil Paint ● Oil paints ,particle of pigment suspended in drying oil (linseed oil), No solvent ● Oil paints can achieve mat and glossy finishes, while being durable and affordable. ● Oil paint is commonly used in walls, doors, windows and metal structures. ● Oil paint is not suitable for humid conditions, and it takes time to dry completely. Enamel Paint ● This type of paint is produced by adding lead or zinc to resinous material.Enamel paints form hard and glossy coatings, which are easily cleaned. They are characterized by being waterproof and chemically resistant. ● Commonly used : Interior and exterior walls, Wood trims, doors, and flooring,Surfaces like wicker, masonry, concrete, plaster, glass, and metals. ● The main limitations of enamel paint are slow drying, and requiring a titanium coating before application (for better appearance). Rs 150/L ++
- 12. Emulsion Paint ● They can be water or oil based,pigments are used to achieve the desired color. ● They are characterized by their fast drying and hardening, and surfaces can be cleaned easily with water. ● Commonly used for interior walls, ceilings and masonry work. For an emulsion paint (used on interior walls and ceilings), 1 litre of paint will cover approximately 12 square metres per coat. ● Some specialized types of emulsion paints can be used for woodwork Synthetic Rubber Paint ● It is made from dissolved synthetic resins, and can include pigments. ● It has a moderate cost ,is chemical and weather resistant and fast drying . ● Synthetic rubber paint is used for concrete surfaces in general, and this includes fresh concrete. Rs 250/L ++ High glossy Rs 80/L++
- 13. Cement Paint ● It is available in powder form, which is mixed with water to achieve paint consistency. ● It is durable and waterproof, and it is commonly used in rough internal and external surfaces. ● It has a long drying time, typically 24 hours,therefore applied in two coats to prevent dampness issues. Casein Paint ● Made from casein mixed with white pigments. ● It is available in powder and paste form, and pigments can be added. ● Commonly used to paint walls, ceilings and wood. Rs 170/bag ++
- 14. Bituminous Paint ● Made from dissolved asphalt or tar, giving it a characteristic black color. ● It is waterproof and alkali-resistant, but not suitable for applications where it will be exposed to the sun, since it deteriorates. ● It is commonly used in underwater ironworks, concrete foundations, wooden surfaces and iron pipes. ● It also helps provide rust resistance when applied in metals. Rs 80/L ++
- 15. Plastic Paint This paint uses water as a thinner, and it is available in a wide range of colors. It dries very quickly and offers high coverage. The following are some common applications: ● Walls and ceilings of auditoriums, showrooms, display rooms, etc ● Slabs, Decks Paint finishes Glossy,matt or flat ,satin,semi gloss Rs 250/L ++
- 16. Method of Application Surface preparation First painters will clean building walls and ceiling with paint scraper, putty knife or sandpaper to remove loose particle and free the walls from dust, grease etc. Interior Painting is a five step process First painters will clean building walls and ceiling 1.Apply primer 2.Apply wall putty 3.Apply wall putty — second coat 4.apply selected paint coat 5.apply selected paint coat — final one Surface preparation Applying Primer Putty coat Paint coat
- 17. Exterior, wood and steel It is a three step process First painters will clean building surface. 1. Apply primer 2. apply selected paint coat 3. apply selected paint coat — final one The following techniques are used for application of paints: ● Brush Roller ● Air spray ● Airless spray ● Electrostatic spray Air spray Airless spray roller Electrostatic painting brush
- 18. Varnishes The varnishes are transparent or nearly transparent solutions of resinous materials and they are applied over the painted surfaces.
- 19. The need for varnishing: ● It brightens the appearance of grade in wood ● It renders brilliancy to the painted surface ● It protects the painted surface from atmospheric actions ● It protects the unpainted wooden surfaces of doors, windows, roof trusses, floors etc., from the actions of atmospheric agents
- 20. Ingredients of Varnishes 1. Resins / Resinous substances: The commonly used resins are copal, lac or shellac and rosin. 2. Driers: The function of a drier in varnish is to accelerate the process of drying. The common driers used in varnishes are litharge, white copper and lead acetate. 3. Solvents: Depending upon the nature of resin, the type of solvent is decided.
- 21. Manufacturing Procedure - Varnishes The natural varnishes are produced by heating the resins, adding natural oils such as linseed oil, cooking the mixture to the desired viscosity, and then diluting it with turpentine. 1. Introducing resin, oil and a gelling agent into a mixing zone 2. Heating the resin, oil, and gelling agent to an elevated temperature 3. Mixing the resin, oil, and gelling agent for a period sufficient to produce varnish 4. Diluting it with turpentine and then continuously withdrawing the varnish from the mixing zone.
- 22. ● It gives glossy surface. ● It is durable. ● It dries rapidly after application. ● It does not develop cracks after drying. ● It is commonly used on wooden surfaces. ● Colour of varnish does not fade away with time. ● It does not hide the natural grain of inner surface of timber. Characteristics Physical Properties of Varnish ● Transparent ● Hard ● Protective ● Glossy but can be designed to produce semi gloss sheens by adding flatting agent.
- 23. Types of varnishes Oil varnishes ● They use linseed oil as solvent in which hard resins such as amber and copal are dissolved by heating. ● These varnishes dry slowly, but form hard and durable surface. ● Sometimes, small quantity of turpentine is added to make the varnish more workable. ● Oil varnishes are recommended for all external wood work, and for joinery and fittings.
- 24. Spirit varnishes or lacquers ● They are methylated spirit of wine as solvent in which soft resins such as lac or shellac are dissolved. ● They dry quickly, but are not durable. ● French polish is a variety of this type varnish. ● It is commonly used on furniture.
- 25. Turpentine varnishes ● They use turpentine as solvent in which soft resins such as gum dammer, mastic and rosin are dissolved. ● The varnish dries quickly, but is not so durable. ● They are cheaper than oil varnishes. Water varnishes ● They are formed by dissolving shellac in hot water, using enough quantity of ammonia, borax, potash or soda. ● Water varnishes are used for varnishing wall papers, maps pictures, book jackets, etc.
- 26. Areas of application Varnish is primarily used in wood finishing applications where the natural tones and grains in the wood are intended to be visible. It is applied over wood stains as a final step to achieve a film for gloss and protection.
- 27. Method of application ● Preparation of surface: The wood surface is made smooth by thoroughly rubbing it by means of sand paper or pumice stone. ● Knotting: The process of knotting is carried out exactly in the same way as adopted for painting wood work. ● Stopping: Stopping is done by means of hot weak glue size so that pores on the surface are filled up. Alternately, boiled linseed oil can be applied in two coats. The dry surface then be rubbed down with sand paper. ● Coat of varnish: On the cleaned surface, two or more coats of varnish are applied. Next coat is applied only when the previous coat has dried up thoroughly. Technique of application: ● natural or synthetic bristle brushes
- 28. Distempers The distempers are applied over the plastered surface to create a smooth surface. They are available in a variety of colours.
- 29. Ingredients of Distemper A distemper is composed of base, carrier and colouring pigment. It is more or less a paint in which whiting or chalk is used as a base and water as a carrier. They are to be mixed with hot water before use. The oil-bound distempers are a variety of an oil paint in which the drying oil is so treated that it mixes with water.
- 30. Manufacturing Procedure - Distempers 1. It is more or less a paint in which whiting or chalk is used as a base and water as a carrier. The main ingredient in distemper is whiting. This is a fine white 'chalky' powder dissolved with water into a creamy paste. 2.The 'binding' ingredient is animal skin glue.The glue is heated to soupy consistency. 3.The whiting and glue are combined and then filtered through a fine muslin. The oil-bound distempers are a variety of an oil paint in which the drying oil is so treated that it mixes with water. As the water dries, the oil makes a hard surface which is washable.
- 31. ● Distemper is low cost water base paint ● Chalk is the base material and carried by water. Product is packed at paste form. ● Suitable for only interior paint ● It is washable paint ● Available in market in the unit of Kg, unlike liters of emulsion base paint. ● Most suitable for tenancy and economical painting ● Durability of this paint could be around 2 years ● This is matt finish paint, unlike most emulsion paint are glossy finish ● Most widely available in Indian market. This product has excellent distribution channel and almost available anywhere in India, because of its economical pricing and demand in market. ● Require at-least 10 hours of ventilation after painting to get rid of paint fragrance. Characteristics
- 32. Physical Properties of Distempers ● Light in color. ● Coatings are generally thick. ● They give reflective coating. ● Less durable than oil paints but cheaper.
- 33. Areas of application: ● Mainly used on cement surfaces ● It can also used in wooden surfaces but requires separate undercoat application
- 34. Method of application: ● Surface preparation - the surface to receive the distemper is thoroughly rubbed and cleaned. ● Application of wall putty ● Primer coat ● Coats of distemper Technique of application: ● Brush ● Roller 1 2 3 4