LIST of BLOGS on COLOURS

COLOURS, COATINGS, PAINTS, PIGMENTS

Post 578 by Gautam Shah

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640px-candy_colours_28209906271829

Colours > Wikipedia image > source Candy by Author terren in Virginia

1 UNDERSTANDING LACQUERS

https://interiordesignassist.wordpress.com/2015/08/16/understanding-lacquers/

2 LACQUERS or NC LACQUERS

https://interiordesignassist.wordpress.com/2014/04/27/lacquers-or-nc-lacquers/

3 SOLVENTS for THINNERS

https://interiordesignassist.wordpress.com/2015/08/09/solvents-for-thinners/

4 WOOD SURFACE FINISHING

https://interiordesignassist.wordpress.com/2015/07/13/wood-surface-finishing/

5 PAINT THINNERS Part 2

https://interiordesignassist.wordpress.com/2015/05/14/paint-thinners-part-2/

6 PAINT THINNERS Part 1

https://interiordesignassist.wordpress.com/2015/05/08/paint-thinners-1/

7 ROSEWOOD

https://interiordesignassist.wordpress.com/2015/03/26/rosewood/

8 INDUSTRIAL PAINT FINISHES

https://interiordesignassist.wordpress.com/2015/03/07/industrial-paint-finishes/

9 APPLICATION of COATINGS

https://interiordesignassist.wordpress.com/2015/01/09/application-of-coatings/

10 COATINGS -Surface finishing technologies

https://interiordesignassist.wordpress.com/2014/11/08/coatings-surface-finishing-technologies/

11 CLEAR COATINGS

https://interiordesignassist.wordpress.com/2014/09/12/clear-coatings/

12 FILM FORMING PROCESS in COATINGS

https://interiordesignassist.wordpress.com/2014/09/03/film-forming-process-in-coatings/

13 WOOD SURFACE PREPARATIONS for CLEAR COATINGS

https://interiordesignassist.wordpress.com/2014/04/28/wood-surface-preparations-for-clear-coatings/

14 SHELLAC COATINGS and FRENCH POLISHES

https://interiordesignassist.wordpress.com/2014/04/26/shellac-coatings-and-french-polishes/

15 VARNISH

https://interiordesignassist.wordpress.com/2014/04/25/varnish/

16 MULTI COATS of PAINT SYSTEMS

http://talking-interior-design.blogspot.in/2014/03/multi-coats-of-paint-systems.html

17 WOOD FINISHES

http://talking-interior-design.blogspot.in/2014/07/wood-finishes.html

18 CLEAR COATINGS

http://talking-interior-design.blogspot.in/2015/03/clear-coatings.html

19 CEMENT SURFACE FINISHES

http://talking-interior-design.blogspot.in/2015/06/cement-surface-finishes.html

Colour Palette

Colour Palette Flickr image by Rocco Lucia

20 CRAFT of WALL PAINTING (Neolithic)

http://talking-interior-design.blogspot.in/2014/02/the-craft-of-wall-painting-neolithic.html

21 CRAFT of WALL PAINTING (Palaeolithic)

http://talking-interior-design.blogspot.in/2014/01/the-craft-of-wall-painting-palaeolithic.html

22 COATINGS

http://talking-interior-design.blogspot.in/2013/09/coatings.html

23 COATINGS Iron age

http://talking-interior-design.blogspot.in/2013/09/coatings-iron-age.html

24 PRIMITIVE COATINGS Surfaces, Materials and Techniques

http://talking-interior-design.blogspot.in/2013/09/primitive-coatings-surfaces-materials.html

25 LIME-WASH

https://interiordesignassist.wordpress.com/2014/06/01/lime-wash/

26 PAINTING WHITE – 1

https://interiordesignassist.wordpress.com/2015/07/27/painting-white-1/

27 PAINTING WHITE – 2

https://interiordesignassist.wordpress.com/2015/07/29/painting-white-2/

28 BLACK Part – 1

https://interiordesignassist.wordpress.com/2015/08/07/black-part-i/

29 COLOURANTS DYES and PIGMENTS

https://interiordesignassist.wordpress.com/2014/07/15/colourants-dyes-and-pigments/

30 RED Colours of ancient times

https://interiordesignassist.wordpress.com/2015/05/22/red-colours-of-ancient-times/

31 ART COATINGS

https://interiordesignassist.wordpress.com/2015/05/25/art-coatings/

32 PRIMITIVE COATINGS # 1

https://interiordesignassist.wordpress.com/2015/05/03/primitive-coatings-1/

33 NATURAL IRON OXIDE PIGMENTS 4 # SIENNA and UMBER

https://interiordesignassist.wordpress.com/2015/05/01/natural-iron-oxide-pigments-4-sienna-and-umber/

34 NATURAL IRON OXIDE PIGMENTS -3 # Ochers

https://interiordesignassist.wordpress.com/2015/04/28/natural-iron-oxide-pigments-3-ochers/

35 NATURAL IRON OXIDE PIGMENTS – 2 # Red Oxides

https://interiordesignassist.wordpress.com/2015/04/27/natural-iron-oxide-pigments-2-red-oxides/

36 FLOOR PAINTS

https://interiordesignassist.wordpress.com/2015/03/21/floor-paints/

37 ARCHITECTURAL COATINGS -beginnings of OIL PAINTS

https://interiordesignassist.wordpress.com/2015/02/15/architectural-coatings-beginnings-of-oil-paints/

38 SURFACE PREPARATIONS

https://interiordesignassist.wordpress.com/2014/09/26/surface-preparations/

39 WHITE PIGMENTS

https://interiordesignassist.wordpress.com/2014/08/05/white-pigments/

40 CEMENT PAINTS

https://interiordesignassist.wordpress.com/2014/07/09/cement-paints/

 

640px-colourful_shoes_in_marrakech

Colourful Shoes Morocco Wikipedia image source > http://www.flickr.com/photo/cloudzilla/2718019182/ by cloudzilla

41 OIL BOUND DISTEMPERS -OBD

https://interiordesignassist.wordpress.com/2014/07/03/oil-bound-distempers-obd/

42 CEMENT FINISHES part 2

https://interiordesignassist.wordpress.com/2014/06/27/cement-finishes-part-2/

43 DRY DISTEMPER or CALCIMINE

https://interiordesignassist.wordpress.com/2014/06/03/dry-distemper-or-calcimine/

44 ECOLOGY and COATINGS

https://interiordesignassist.wordpress.com/2015/03/09/ecology-and-coatings/

45 ENCAUSTIC PAINTING

https://interiordesignassist.wordpress.com/2014/06/06/encaustic-painting/

46 COLOURS and BUILDINGS

https://interiordesignassist.wordpress.com/2015/01/20/colours-and-buildings/

47 GLOSS

https://interiordesignassist.wordpress.com/2014/09/20/gloss/

48 COMPOSITION of COATING

https://interiordesignassist.wordpress.com/2014/07/29/composition-of-a-coating-3/

49 COLOURED GLASS

https://interiordesignassist.wordpress.com/2014/08/03/coloured-glass/

50 GRISAILLE -monochrome form of presentation

https://interiordesignassist.wordpress.com/2014/07/28/grisaille-monochrome-form-of-presentation/

51 WATER COLOURS

https://interiordesignassist.wordpress.com/2014/07/10/water-colours/

52 FRESCO PAINTINGS

https://interiordesignassist.wordpress.com/2014/06/24/fresco-paintings/

53 PRIMER COATINGS

https://interiordesignassist.wordpress.com/2015/06/07/primer-coatings/

54 SINGLE or MULTI COAT SYSTEMS

https://interiordesignassist.wordpress.com/2015/05/30/single-or-multi-coat-systems/

55 BRUSHES

https://interiordesignassist.wordpress.com/2015/03/29/brushes/

56 ENAMELS

https://interiordesignassist.wordpress.com/2015/02/18/enamels/

57 TEMPERA

https://interiordesignassist.wordpress.com/2015/01/24/tempera/

58 GP -General purpose paints

https://interiordesignassist.wordpress.com/2014/08/26/gp-general-purpose-paints/

59 COLOURS -Perception and Expression

https://interiordesignassist.wordpress.com/2015/03/07/colours-perception-and-expression/

Acrylic Colours stux

Acrylic art colours Pixabay image by stux

60 EMULSIONS

https://interiordesignassist.wordpress.com/2016/01/30/emulsions/

61 CLEAR versus PIGMENTED COATINGS

https://interiordesignassist.wordpress.com/2015/11/29/clear-versus-pigmented-coatings/

62 SELECTING and APPLYING a COATING

https://interiordesignassist.wordpress.com/2015/11/27/selecting-and-applying-a-coating/

63 COLOUR MODELS (RYB)

https://interiordesignassist.wordpress.com/2015/10/14/colour-models-ryb/

64 BLACK Part – II

https://interiordesignassist.wordpress.com/2015/09/17/black-part-ii/

65 MASONRY PAINT FINISHES

https://interiordesignassist.wordpress.com/2015/11/17/masonry-paint-finishes/

Artists coloursby skeeze

Artists’ colours Pixabay image by skeeze

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SELECTING and APPLYING a COATING

Post 552  by Gautam Shah

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Nepal painters Flickr image by Wonderlane

Coatings are selected in consideration of the substrate (virgin or already coated surface), application technology and atmospheric conditions. Commercially coatings are available for broad categories of surfaces, such as masonry, wood, metals; for specific layering such as primer, undercoating, top or finishing coating; for purposes such as architectural, industrial, marine, clear coatings, food-grade; for technical applications such as water-proofing, insulating, mastic compounds, fire-retardant or proofing, conductive or anti-static etc.

680px-building_painting_6252

Wikipedia image by Biswarup Ganguly

Selection of a Coating is done in view of following factors:

  1. Appearance (colour -hue, tone) (texture -sheen, gloss)
  2. Weather properties
  3. Abrasion resistance
  4. Adhesion to the substrate
  5. Impact resistance
  6. Flexural qualities
  7. Recoatability
  8. Drying time (touch dry, hard dry or use ready)
  9. Feasible drying techniques ( Air dry, baking, catalytic)
  10. Resistance to a given medium (sea water, alkaline or acid, chlorine and sulphur)
  11. Resistance to sunlight (direct sunlight and UV component)
  12. Antistatic properties
  13. Temperature resistance
  14. Odour
  15. Solvent vapour hazards (VOC)
  16. Ecological value
  17. Application environment (open, enclosed, controlled, inclement)

574px-worker_applying_a_wood_finish

Wikipedia image by Vermont Timber Works Inc.

General Rules of application

Many of these rules are more pertinent to Alkyd resin-based coatings, rather than Latex or Plastic polymer-emulsion-based coatings. Both often contain anti-settling agents that retard the separation of solids from liquid components. The Plastic paints now contain thixotropic agents that induce false viscosity when the coating material is at rest, but once stirred temporarily gains normal or applicable viscosity.

1 The tins, drums, carboys, Jerry-cans of coatings, primers and undercoats should be delivered on a site, at least 24 hours before the job and allowed to rest, and revert to the site temperature.

2 All packing of coating materials, except solvents, should be placed upside down for at least 24 hours, prior to the job (relevant for An Alkyd resin based pigmented coatings or oil paints, primers etc.)

3 Always draw just sufficient material that can be used immediately (-if enamel, preferably within an hour, and, -if lacquer, much shorter duration).

4 Do not pour back any colour that has been drawn out and exposed to the atmosphere. Before closing a partly used tin, pour a small quantity of miscible solvent or thinner over the surface to prevent skinning and evaporation of volatile substances.

5 Atmospheric conditions should normally remain consistent (ideal temperature range between 10°C to 35°C, humidity 50% and breeze velocity at 20 km per hour) for the entire duration of application, and curing or drying. The surface to be coated must be at the ambient temperature. All direct sun-rays (even for exterior coatings), except of the early morning, should be avoided for the entire period of application and till the coating is `touch dry‘.

6 Tint the undercoat slightly lighter than the final coat to differentiate and ascertain the full coverage by the final coat.

7 Where very light shades (`off whites‘) are to be mixed on a site, first reduce the tinting-paste with a small amount of white paint, and then adjust the final shade with the reduced tinter. To match a very light shade, place a drop of mixed trial colour on white paint wet-surface, and judge the difference. Certain high tinting pigments, such as blue, black and red are required in extremely small portions, and are difficult to mix in base white or lighter shade. Such coatings turn out to be slightly darker and sometimes have streaks, because brushing or rolling enhances the dispersion of pigments. To avoid this it is better to filter out all the site-mixed colours with a Nylon or Polyester fine-mesh cloth (bolting cloths, used for making screens for screen printing).

8 Water based coatings, dry out to a lighter shade then their wet look and Oil or resin-based coatings dry out to a darker shade then their wet look.

9 Never apply a very thin coat, or a thicker coat, than recommended by the manufacturer.

10 Apply the first coat in the direction of fibres or texture grains of the substrate. Apply the next coat in the cross direction, observing that the final coat on vertical surfaces is always in a vertical direction. It is always better to apply the final coat in direction of length then width.

11 Allow sufficient time for each coat to thoroughly cure or dry out, before any new coating or treatments (like sandpapering, rubbing) are done. Learn to differentiate between a `touch dry’ and ‘through dry’ conditions of a coating. Convertible coatings1 should not be re-coated before these are thoroughly dry, but Non-Convertible coatings2 can be re-coated when substantial part of solvent material has evaporated. Non convertible coatings can develop an inter layer adhesion. Both types of coatings, though may not be brush coated before through drying. Non-convertible coatings, however, may be re-coated by spray method.

12 Allow sufficient time before the coated object is used for intensive service (quite often it may take 7/15 days after `through dry’ conditions), because it takes longer for the inner section of coating to become thoroughly dry.

640px-thumbnail

Marine Painting

*(1) Convertible Coating > The film forming substance on drying or curing coverts itself into a different material, which cannot be reverted by any process like solution, heating, etc.  Dried out Oil paints cannot be dissolved.

*(2) Non-Convertible Coating > The film forming substance on drying can be reconverted into original like material by solution or heat softening. NC Lacquers are such coating materials.

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LIST of BLOGS on LACQUERS, PAINTS and THINNERS

Post 499  by Gautam Shah

1 UNDERSTANDING LACQUERS

https://interiordesignassist.wordpress.com/2015/08/16/understanding-lacquers/

2 LACQUERS or NC LACQUERS

https://interiordesignassist.wordpress.com/2014/04/27/lacquers-or-nc-lacquers/

3 SOLVENTS for THINNERS

https://interiordesignassist.wordpress.com/2015/08/09/solvents-for-thinners/

4 WOOD SURFACE FINISHING

https://interiordesignassist.wordpress.com/2015/07/13/wood-surface-finishing/

5 PAINT THINNERS Part 2

https://interiordesignassist.wordpress.com/2015/05/14/paint-thinners-part-2/

6 PAINT THINNERS Part 1

https://interiordesignassist.wordpress.com/2015/05/08/paint-thinners-1/

7 ROSEWOOD

https://interiordesignassist.wordpress.com/2015/03/26/rosewood/

8 INDUSTRIAL PAINT FINISHES

https://interiordesignassist.wordpress.com/2015/03/07/industrial-paint-finishes/

9 APPLICATION of COATINGS

https://interiordesignassist.wordpress.com/2015/01/09/application-of-coatings/

10 COATINGS -Surface finishing technologies

https://interiordesignassist.wordpress.com/2014/11/08/coatings-surface-finishing-technologies/

11 CLEAR COATINGS

https://interiordesignassist.wordpress.com/2014/09/12/clear-coatings/

12 FILM FORMING PROCESS in COATINGS

https://interiordesignassist.wordpress.com/2014/09/03/film-forming-process-in-coatings/

13 WOOD SURFACE PREPARATIONS for CLEAR COATINGS

https://interiordesignassist.wordpress.com/2014/04/28/wood-surface-preparations-for-clear-coatings/

14 SHELLAC COATINGS and FRENCH POLISHES

https://interiordesignassist.wordpress.com/2014/04/26/shellac-coatings-and-french-polishes/

15 VARNISH

https://interiordesignassist.wordpress.com/2014/04/25/varnish/

16 MULTI COATS of PAINT SYSTEMS

http://talking-interior-design.blogspot.in/2014/03/multi-coats-of-paint-systems.html

17 WOOD FINISHES

http://talking-interior-design.blogspot.in/2014/07/wood-finishes.html

18 CLEAR COATINGS

http://talking-interior-design.blogspot.in/2015/03/clear-coatings.html

19 CEMENT SURFACE FINISHES

http://talking-interior-design.blogspot.in/2015/06/cement-surface-finishes.html

20 CRAFT of WALL PAINTING (Neolithic)

http://talking-interior-design.blogspot.in/2014/02/the-craft-of-wall-painting-neolithic.html

21 CRAFT of WALL PAINTING (Palaeolithic)

http://talking-interior-design.blogspot.in/2014/01/the-craft-of-wall-painting-palaeolithic.html

22 COATINGS

http://talking-interior-design.blogspot.in/2013/09/coatings.html

23 COATINGS Iron age

http://talking-interior-design.blogspot.in/2013/09/coatings-iron-age.html

24 PRIMITIVE COATINGS Surfaces, Materials and Techniques

http://talking-interior-design.blogspot.in/2013/09/primitive-coatings-surfaces-materials.html

25 LIME-WASH

https://interiordesignassist.wordpress.com/2014/06/01/lime-wash/

26 PAINTING WHITE – 1

https://interiordesignassist.wordpress.com/2015/07/27/painting-white-1/

27 PAINTING WHITE – 2

https://interiordesignassist.wordpress.com/2015/07/29/painting-white-2/

28 BLACK Part – 1

https://interiordesignassist.wordpress.com/2015/08/07/black-part-i/

29 COLOURANTS DYES and PIGMENTS

https://interiordesignassist.wordpress.com/2014/07/15/colourants-dyes-and-pigments/

30 RED Colours of ancient times

https://interiordesignassist.wordpress.com/2015/05/22/red-colours-of-ancient-times/

31 ART COATINGS

https://interiordesignassist.wordpress.com/2015/05/25/art-coatings/

32 PRIMITIVE COATINGS # 1

https://interiordesignassist.wordpress.com/2015/05/03/primitive-coatings-1/

33 NATURAL IRON OXIDE PIGMENTS 4 # SIENNA and UMBER

https://interiordesignassist.wordpress.com/2015/05/01/natural-iron-oxide-pigments-4-sienna-and-umber/

34 NATURAL IRON OXIDE PIGMENTS -3 # Ochers

https://interiordesignassist.wordpress.com/2015/04/28/natural-iron-oxide-pigments-3-ochers/

35 NATURAL IRON OXIDE PIGMENTS – 2 # Red Oxides

https://interiordesignassist.wordpress.com/2015/04/27/natural-iron-oxide-pigments-2-red-oxides/

36 FLOOR PAINTS

https://interiordesignassist.wordpress.com/2015/03/21/floor-paints/

37 ARCHITECTURAL COATINGS -beginnings of OIL PAINTS

https://interiordesignassist.wordpress.com/2015/02/15/architectural-coatings-beginnings-of-oil-paints/

38 SURFACE PREPARATIONS

https://interiordesignassist.wordpress.com/2014/09/26/surface-preparations/

39 WHITE PIGMENTS

https://interiordesignassist.wordpress.com/2014/08/05/white-pigments/

40 CEMENT PAINTS

https://interiordesignassist.wordpress.com/2014/07/09/cement-paints/

41 OIL BOUND DISTEMPERS -OBD

https://interiordesignassist.wordpress.com/2014/07/03/oil-bound-distempers-obd/

42 CEMENT FINISHES part 2

https://interiordesignassist.wordpress.com/2014/06/27/cement-finishes-part-2/

43 DRY DISTEMPER or CALCIMINE

https://interiordesignassist.wordpress.com/2014/06/03/dry-distemper-or-calcimine/

44 ECOLOGY and COATINGS

https://interiordesignassist.wordpress.com/2015/03/09/ecology-and-coatings/

45 ENCAUSTIC PAINTING

https://interiordesignassist.wordpress.com/2014/06/06/encaustic-painting/

46 COLOURS and BUILDINGS

https://interiordesignassist.wordpress.com/2015/01/20/colours-and-buildings/

47 GLOSS

https://interiordesignassist.wordpress.com/2014/09/20/gloss/

48 COMPOSITION of COATING

https://interiordesignassist.wordpress.com/2014/07/29/composition-of-a-coating-3/

49 COLOURED GLASS

https://interiordesignassist.wordpress.com/2014/08/03/coloured-glass/

50 GRISAILLE -monochrome form of presentation

https://interiordesignassist.wordpress.com/2014/07/28/grisaille-monochrome-form-of-presentation/

51 WATER COLOURS

https://interiordesignassist.wordpress.com/2014/07/10/water-colours/

52 FRESCO PAINTINGS

https://interiordesignassist.wordpress.com/2014/06/24/fresco-paintings/

53 PRIMER COATINGS

https://interiordesignassist.wordpress.com/2015/06/07/primer-coatings/

54 SINGLE or MULTI COAT SYSTEMS

https://interiordesignassist.wordpress.com/2015/05/30/single-or-multi-coat-systems/

55 BRUSHES

https://interiordesignassist.wordpress.com/2015/03/29/brushes/

56 ENAMELS

https://interiordesignassist.wordpress.com/2015/02/18/enamels/

57 TEMPERA

https://interiordesignassist.wordpress.com/2015/01/24/tempera/

58 GP -General purpose paints

https://interiordesignassist.wordpress.com/2014/08/26/gp-general-purpose-paints/

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SOLVENTS for THINNERS

Post 492  by Gautam Shah

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Thinners are combination of ‘solvents’ whereas a solvent is single liquid material. Thinners and solvents are used for many purposes. These can be categorized in roughly THREE categories: 1 as a solvent for reducing the viscosity, 2 as a diluent an intermediating agent, and 3 as a non active carrier agent.

As a viscosity reduction agent it is used with resins, coating materials, adhesives, etc. As a diluent it is used as an extender medium in thinners to extend thereby reduce the cost of costly solvents. As non active material it is used with pesticides, chemicals to achieve greater spread. Some solvents of very low boiling point temperature are used as carrier for sprays etc. Thinners or solvents are used for cleaning surfaces such as restoration of artwork, removal of oil-grease deposits, removal of moisture from very thin crevices such as electronic circuits.

Distillation of crude oil at different temperatures

One of the earliest needs for a solvent was to reduce the viscosity of wax without warming it with heat. Wax was one of the best and easily available waterproofing material, but required heat for softening, a highly dangerous fire prone processes. Similar problems were encountered while thinning vegetable oils, tallow and other fats. These issues were solved with some of the earliest solvent materials the turpentine and the spirits (crude ethanol-based products from fermentation-distillation processes). Turpentine has been known as: spirit of turpentine, natural turpentine, genuine turpentine, oil of turpentine, wood turpentine and turps.

Oil_of_turpentine

Turpentine is a steam distillation product from leaves of pine trees which also yields gum turpentine, turpentine oil and colophony (rosin). All these products have been used by artist for artwork and by crafts persons. The primary use of turpentine has been as a solvent for paints. During last century menthol and camphor were produced for turpentine, of this camphor was used for early Nitro-cellulose lacquer (NC Lacquer). Artists preferred distilled Turpentine as paint medium as it was more viscous than white spirit, and for being slow to evaporate. The later property was useful for ‘touching’ the colours, and keep it alive (green or wet) for longer duration. Residues or trace gum rosin in Turpentine prevents fast drying of film and keeps it tacky for along time.

White_spirit

During the last century Genuine Turpentine has been replaced by Mineral Turpentine. Mineral Turpentine is petroleum distillate and is also known as white spirit, petroleum spirits, solvent naphtha. It is a very efficient solvent for oil and alkyd-based paints and varnishes. It is as low cost as Kerosene and so used for cleaning oil-grease from engineering products and other dry-cleaning (non-water cleaning of garments, wools) purposes. Turpentine has very little or no odour, so for paint thinner of domestic use, little terpene oil or genuine turpentine is added as a flavouring agent.

ethanol1Alcohol is produced through fermentation-distillation. The resultant product is Ethyl alcohol (Ethanol). The word Ethyl derives from French word ether, meaning a substance that evaporates fast at room temperature. Alcoholic drinks through fermentation of grapes, berries, honey and rice were produced since 7000 BC. Spirit or ethanol was used to dissolve plant gums. Ethanol is miscible with water and its presence reduces the surface tension of water. Pure ethanol is misused for consumption, so many countries have made it compulsory to denature it adding 5% or more methanol. This is also called methylated spirit. Denatured spirits are used for dissolving gums and shellac to formulate ‘French Polish’ and Lac and rosinated Varnishes. It is also used as cleaning agent.

Kerosene is chiefly used as a fuel. There are commercial and superior grades available. It has very strong solvent properties. In far off regions where Mineral turpentine is not available, Kerosene is used as oil paint solvent.

Naphtha sold as Camp-fuel

Naphtha is a flammable liquid mixture consisting of hydrocarbons, and it is very similar to kerosene or gasoline. It is a feed material for fertilizer and chemical plants. It is used for cleaning(flushing out) petroleum product tankers and as a tool machine cleaning solvent.

Gasoline is basically a fuel product, but is used for removing grease, tars and waxes from tools, parts and equipments. It is not used for paints.

Water is universal solvent. Water was used for water-based coatings produced from gums, casein, egg-whites etc. and with cementious compounds like lime, gypsum, etc. Water emulsified, polymer paints are able to meet the ecological concerns for VOC (Volatile organic compounds are organic chemicals that has a high vapour pressure at ordinary room temperature).

Acetone

Acetone is a simplest ketone and called mother of solvents. It is colourless and flammable liquid utilized as an important constituent of lacquer thinner, nail polish remover and grease-oil cleansing. In restoration and conservation practices acetone is often used to clean dirt, soot and grime and old varnishes from paintings and furniture.

Olivia Boteler Porter before and after restoration – removal of yellowing due to dirt and ageing

Methyl ethyl ketone (MEK) is an industrial solvent which is easily miscible with water. It is used as thinner solvent and as a remover-softener of stubborn paints.

Carbon tetra-chloride fire extinguisher 1930

Carbon tetra-chloride is also known as tetrachloromethane, carbon tet (cleaning industry), Halon-104 (firefighting) and Refrigerant-10 (HVACR). It was very popular cleaning agent for amateur electronics people. It is a colourless liquid with a sweet smell detectable at low levels. It is no longer preferred as a solvent or cleaning fluid.

 Sistine Chapel, the prophet Daniel before and after Restoration

>> A decision was made that all of the shadowy layer of animal glue and “lamp black”, all of the wax, and all of the over-painted areas were contamination of one sort or another: smoke deposits, earlier restoration attempts, and painted definition by later restorers in an attempt to enliven the appearance of the work. Based on this decision, according to Arguimbau’s critical reading of the restoration data that have been provided, the chemists of the restoration team decided upon a SOLVENT that would effectively STRIP the ceiling down to its paint-impregnated plaster.

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PAINTING WHITE – 2

Post 485  by Gautam Shah

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During 1930-50s Paint shops used to offer Oil-bound Distempers (OBD) and combination of Zinc pastes and double-boiled Linseed oil, for household painting. These were mixed with pigment pastes for shade creation. Post 1950s ready mixed oil paints or General purpose enamels (GP) became popular. But than paints’ shops had to stock several tins of different measures, for each of the shades and varieties (oil paints, distemper paints, flat and egg-shell plastic paints). And to match a desired shade, it was necessary to buy small bottles or vials of concentrated pigment pastes called tinters and top up an available shade or create one from a white.

Paint Shop of earlier era

There were two whites available, a ‘super-whitewith some form of ‘optical whitener or brightener, an ‘opacifier’ or colourants like blue or violet, and pure stuff called base-white, without any additives. Few lay people were aware of the later variety, or considered it to be some inferior stuff due to its less romantic name (super white versus base-white), and discounted price.

Zinc paste-based paints and General purpose enamels had linseed oil or its alkyd resins as the chief film forming material. The linseed has a tendency to oxidize and turn yellow over the age. This began to change due to strong demand from manufacturers of white-goods (consumer goods painted white such as ovens, fans, washing machines, refrigerators, etc.) for long-term non yellowing finishes. This led to use of non yellowing oils for resins, and new generation formulations of Urethane, Amino resins and epoxies. The same innovations began to percolate to home-paint markets. From 1960s Plastic polymer-based emulsion paints (called Latex paints in USA) began to be available. This offered non-yellowing white paints.

Shade Card

Titanium Dioxide as a whitest pigment had few technical problems of paint formulations, but these were initially solved with use of Zinc and Lithopone as additives. Oil paints in glossy and flat varieties, and Plastic Paint with, sheen, egg-shell-matt and flat varieties now were offered as one or two coat systems. This high hiding-covering was due to excellent pigment grinding-dispersion in machines like attritors that replaced ball and roller mills.

United States Capitol west front

Paint markets are now radically changed. Paints manufacturing companies depend on shops to match the colour shades. The shades are created from basic, and few vials of ground pigments, which inject exact-micro quantity of colours into range of base formulations. The base formulations, include nearly clear to several types of white paints. White bases have natural shades of white pigments, and some have whitening-opacifiers. A white base is used for light tints, but not more than 100 ml paste can be added for darker shades to avoid loss of gloss or the effect on drying time. A neutral, pastel or mid-base contains lesser quantity of white pigment and is used for creating darker colours. And a clear base is used (it may contain white powders of low refractivity or extenders, but is free of high refractivity white pigments), for very deep colours. Some manufacturers use this base to add little sheen to matt paint.

Whites are affected by surroundings and show many variations

Whites are affected by smallest amount of additive colourants. These colourants may come from residues of earlier colour in brushes or rollers, any loose particles on the surface to be painted and thinners (solvents and water). Some additive colourants, if not thoroughly mixed, begin to darken the colour shade over brushing or rolling. Extra ordinary care is required in selecting, buying, mixing and using, white and ‘off-white’ shades. Shops have a file of colour shade cards, which are rarely fresh. The shade card viewing must be done in natural light, as it is affected by the surroundings and type of illumination. Shop computer calibrated and mixed shades, are not necessarily exactly right as per the shade card or as per your need.

A colour shows many variations at different angles of viewing and so colour matching must be done perceiving it from as many positions > Pic by https://www.flickr.com/photos/horiavarlan/4271993197

One of the best ways is to buy a small trial pack, and apply it on two different walls (preferably at right angles), at the site location. Once a right shade is achieved, leave some quantity (see the next paragraph) in the trial pack for master batching and matching.

HOW to mix a white shade with very light tinge of other colours at home? Buy the most appropriate white-base out of several ones available at a paint shop (usually 2-6 varieties). Now separately mix the concentrated tint to small quantity of white-base, with shade as close matching to your desire. Such faint tinges of colours are very difficult to visually perceive. So place a drop of experimental mix over the quantity left in trial pack. Your shade will be either darker or lighter, but easily perceptible.

White shades1

Most plastic emulsion paints now have a ‘Thixotropic’ compound, which gives a heavy, butter like false viscosity to the paint, to prevent separation or settlement of heavier phases or solids. Stirring is required to reconvert the stuff to a temporary liquid phase. Plastic paints come with good odours, to suppress the unpleasantness of paints, but one need not judge a paint on that count.

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PAINTING WHITE – 1

PAINTING WHITE – 1

Post 483  by Gautam Shah

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Painting anything white is easier said than actually achieved. Lovers of white are like ‘platonic lovers’ and so are confused as to what colour needs be used. The sensual lethargy arises because there are too many tinges, chroma, hues and tones of colours in the market to select from, and earlier affairs have been disappointing. Some lack the daring to experiment, or incapable of orchestrating coordinated response with the variety. And to this, the response is extremist, not only white is sought, but want whitest white and everywhere. The maddening craze cannot be achieved on own, through a painter, or a novice designer. It needs help of a person of experience with technical know-how.

White Sands Pensacola Beach, Florida USA

A white colour seems different to different people, in specific environmental conditions, spatial settings, and most importantly in presence of other colours, in proximity or even memory. There are many examples of whites around us, Clouds, vapour, milk, flowers, teeth, bones, cotton, snow, swans, ducks, rabbits, and skies. Then why is it so difficult to colour anything white? Nature has provided one of the most abundant materials to create the white, Lime or Calcium Carbonate. There were several other minerals like China clay or Kaolin (so-called after the towns of Gaoling or Kao-Ling in Jiangxi province, China), Magnesium carbonate (Magnesium was first discovered outside of the Greek city of Magnesia), Talc, Diatomaceous earth, Marble dust, etc.

White Cliffs of Dover

 A white is effective due to the high refractive index. Lime powder and gesso (China clay, gypsum), were the first whites available in prehistoric times. These were used for levelling the surface and for creating a white ground. As per the modern day terminology both the materials are not white pigments, but extenders. A white pigment has refractive index, above 2.0 (Titanium Dioxide Rutile grade -2.73, Titanium Dioxide Anatase grade -2.55, Antimony Oxide 2.09-2.29, Zinc Oxide -2.02, White Lead basic Carbonate 1.94-2.09), where as most extenders have refractive index range of 1.65. This in very simple terms means that a white colour will have low covering-hiding capacity and so seem ‘dull’ or transparent white, if entirely or partly made of extenders. A white colour of Titanium Dioxide will seem ‘full’ or opaque white.

by JJ Harrison (jjharrison89@facebook.com) Wat Rong Khun, Chiang Rai, Chiang Rai Province, Thailand

Pigment Volume Concentration -PVC is relative proportion by volume of pigment to a resin (binder). Glossy paints have lesser volume of (17%) pigments compared to semigloss 25 % and flat paints can have 38-40 %. It is preferable to use a flat paint over fresh plaster, as it levels the surface better, but a flat paint on a virgin surface may look extra flat, due to greater absorbency.

Pic by Luc Legay on Flickr > Fascination of all White party

Lead white was used by artists and decorators for several centuries in spite of its known toxicity. Greeks called it Psimithium and Romans Cerusa. Most of the older classical oil paintings were created over a lead white canvas primer coat. White Lead or Basic Carbonates pigment in linseed oil paints offered good adhesion and brush-ability and so was used for creating highlights in canvas painting. Zinc oxide, was known as a medical material for open wounds as mentioned in the Indian medical text ‘Charaka Samhita’, from 500 BC or before. Zinc white was accepted as a pigment for linseed oil-based paints for paintings by 1834. Lithopone is a white pigment, a mixture of barium sulfate and zinc sulfide. It was used as a substitute or supplement for toxic white lead.

National Library of India Calcutta

Titanium Dioxide as a white pigment was discovered in 1821, but its commercial use as pigment began in 1921. It has a tinting strength far superior to any other white. In artistic oil pastes, it dries to a spongy film, so needs to be mixed with Zinc or Lithopone. Cheaper brands of paints or Oil bound distempers (OBD) often use titanium dioxide mixed with barytes or other pigments, but at the cost of brilliance and tinting strength. Titanium dioxide ranges of pigments are nontoxic.

Oia Santorini Greece

To be continued to Painting White -2

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COATINGS as thin Surfacing

COATINGS as thin Surfacing

Post 482  by Gautam Shah

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Coatings are thin surfacing with or without a colourant additive. The colourant if present, may be transparent, translucent or opaque. Coatings consist of many different components, such as a film forming substance, and additives like, colourant, reactive agents, solvents etc. In a very complex coating composition such clear-cut distinctions are not apparent, because film forming substances and additives serve purposes beyond their nominal roles. Historically coatings were created as art medium for illustrative and decorative effects. These then began to be used to alter the appearance, improve the tangibility and to provide a protective cover to objects and human body.

Toroid_electronic

Phenolic Varnish coated Copper coil

Coatings are used for 1 changing the quality of the existing surface, and 2 applied as a permanent cover over an object. In the first case the changes are just few molecules deep, like: removal of few molecules of the object or some products from the surface section, rearrangement of the molecules, varied chemical formulation. In second case a composition is applied as a permanent coating, through bonding processes like adhesion, cohesion, chain linking, and material-phase change, intermolecular interactions including van der Waals forces, hydrogen bonds and strong covalent bonds.

Internal coating

Surface Treatments form a very important section of coating technology. Some surface treatments are temporary and are removed once the required action is accomplished, others remain as full or partial deposition. Many surface treatments serve specific purposes such as cleaning, roughening, smoothening, etching, moisture proofing, rust inhibiting, air barriers, static arresters etc. Some others only facilitate the application, setting or drying of the coating.

Anti Glare / Anti reflection coating on Glass

Traditional Coatings are usually liquids of low solids content. These first ‘dried’ by evaporation of substantial content of organic solvents, and later ‘set or hardened through oxidation and long chain formation. This technology began to fad out with use of Plastic or latex paints. These are applied as aqueous dispersions or water-based emulsion of polymers. Now formulations are also solvent less or powder coatings.

Micro Surfacing Road Paver

At application-stage the film-forming mediums are in various phases such as liquid, solid or vapour, or a combination thereof like, suspensions, solutions, dispersions, emulsions, thermoplastic compounds, thixotropic compounds, etc., but coatings once applied ultimately settle to a heavier phase, usually (but not necessarily) a solid phase.

Roof underside fireproof coating

At an application stage a lower phase helps in many ways. Mainly due to liquid state there is uniform and thin level of application. Liquid state of the material permits better dispersion of costly or rare constituents. During application the integrity (thorough dispersion of constituents) can be maintained. Energy required for application of coating is very small. Liquid coatings can be formulated for varied but controlled deposition and rate of phase conversion, to match the substrate and environmental conditions.

Glazed Bakery products

Coatings form a continuous film and so do not have joints, except at junctions where coating application is delayed (a dried out portion and a fresh coat touch each other or overlap). Coatings are thin surfacing so the coated entity remains malleable, and allow the post-forming operations (e.g. coated metal sheets). A coating film has a thickness ranging from 0.0005 to 0.5 mm (0.00002 to 0.02 inch). Coatings are deposited on the entity by many different techniques such as daubing, brushing, spraying, screen printing, roller coating, and dipping.

Wood Deck staining – Coating

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