The earliest known paintings were found in the Lasgaux caves in Southwestern France and also in the Altamira cave in Spain dating from as early as 15000 BCE. A thousand years later the Egyptians were making colours from soil and importing dyes such as Indigo and Madder which they added materials like Gum Arabic, Egg white, gelatin and beeswax, later on they developed varnish from gum Arabic around 1000 BCE. Now days modern technology has now made paint both a decorative and a protective finish.
Paint is commonly defined as a substance that can be applied to surfaces to make a film, whether white, black or colored, and now has been expanded to include clear films.
A study by the John Hopkins University has shown that certain colour environments helped to improve students performance in class.
The components of paints
Back in the 1900 and 1950’s Lead was a major ingredient used in paints but now days with its harmful effects it has been prohibited to be used. Todays paints includes four basic ingredients
Pigments – which gives the colour to the coating
Binders – holds the pigments particles together and provides washability/scrub ability, chemical resistance, durability and other properties
Solvents – makes the coating wet enough to spread on the surface.
Additives – gives it special functions and to perform better
These consist of powdered solids like titanium oxides and silicates which gives the coating its colour and brightness. Different pigments have different purposes, Titanium dioxide is the best for white pigment for hiding power, extender pigments such as calcium carbonate are inert
Binders are liquid adhesives, we would be looking at alkyd, resin, latex and urethane or polyurethane, which form a film of pigment particles on the surface. This sticky resin and adhesives are the vehicle for binding the pigments to the surface creating a strong and long lasting bond. Paints are usually classified as solvent based or water based, when the lid is open too long to exposure of oxygen the drying of the paint starts and the water evaporates this occurs with water based coating.
Solvents are liquids like water and mineral spirits which makes it easier for the product to be applied to surfaces. Solvents can also be called thinners or paint thinning. Solvents help to apply the ingredients to the surface much easier, without this solvent the paint would be thick. When the paint is applied to the surface when drying for sometime the solvent will evaporate
Additives are special purpose ingredients that help to enhance the products performance. The combination of these four ingredients is what makes a particular type and quality of paint.
Solvent based paints – uses a petroleum derivative as the solvent, about fifty years ago, most paint was solvent based. You will find that solvent based paints contain higher levels of organic materials than water-based coatings. This type of paint has a better flow out and a better appearance, odour maybe a bit strong and can take up to 24 hours before being over coated.
Water-based paints – more user friendly and smells a lot less than solvent based paints, much kinda to paint equipment, in the right conditions this paint will dry quickly. When the paint is applied to a surface, the water evaporates, and individual resin particles become closely packed together, this usually takes 4 hours to dry. Performs well in all kinds of weather conditions. If you find that your paint tends to peel then this will be the perfect solution in rectifying this problem. Water-based latex paint is not made with latex rubber, the name latex is just for decorative purposes, it’s a carefully formulated polyvinyl material with acrylic resin, people who have a sensitivity to latex products are no longer in danger of having a bad reaction.
Few things to keep in mind with water-based paints
It is non flammable
Comes in a full range of colours
Usually touch dry in 20-30 minutes
Its not suitable for all window frames
Retains its sheen in UV for long periods
Resistant to alkalis in zinc-rich metals
Stain – this type of coating contains all four ingredients but uses a unique binder. The binder in stains causes the coating to penetrate deeply into the surface which leaves a thinner film on top. This extra layer allows the natural form of the surface to show through. Stains has a low content of binder and pigment solids which results in a shorter life period. This type of coating can be used on wood and other surfaces to show some of their natural beauty.
Clear coating – often used when a person wants additional protection for their surface. Something like varnish or urethane.
Things to remember with paint usage
- You should not order more than you need and make sure to use it all, an extra coat will give it more protection
- Leftover painted can be donated to a local charity or someone that can use it, make sure when you give it away that its in the original container with the labels intact
- Leftover paint should never be poured down household sinks, toilets or drains, to dispose of latex paints, leave it to dry by removing the lid and allowing the water to evaporate. Keep away from children and animals, when dry it can be disposed off making sure the lid is left off for the person collecting it to see that it is hardened.
- For disposal of solvent based paints contact the local or state government environmental agency for disposal guidance.