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Painting Contractors in Sandton

With names like “PVA”, “Acrylic”, “Enamel” and the like it is easy to get confused unless you understand at least a little about paints. Ending up with the wrong paint is not only expensive it can become a DIY nightmare, not to mention embarrassment!

Only two types of paint exist– water based or oil-based. All paints consist of a liquid part and a pigment, or colouring agent. The liquid medium is used to support the pigment and it is this liquid that is either water-based or enamel. To better understand this the name acrylic is given to water-based paints while enamel is the name used to identify oil-based paints.

Different types of paint

• Acrylic - Water based paint
• Emulsions - A water based or acrylic paint
• Enamel - An oil-based paint, usually glossy in appearance when dry
• PVA (Polyvinyl Alcohol) - Used as an adhesive or thickener in acrylic paints.
• Primer -  A “matte” paint used to prepare a surface before its final coat
• Varnish - A clear and transparent paint that has no pigment which is used as a protective coating to seal and protect the paint

What are the Differences between Enamel and Acrylic paints

The base used in enamel paint is linseed oil. The base contained in acrylic paints is an acrylic polymer emulsion, which binds it. The main difference between the two is the amount of drying time needed. Slow drying can in fact be an advantage at certain times as it allows more time for the colours to blend “even out”.

Even fast evaporation of water in acrylic paints can be slowed with the addition of glycerine based additive, or “acrylic retarders”.

1. Enamels Enamel paints offer higher resistance to abrasions, they are glossier and once applied the end result is somewhat smoother. They are able to seal stains because they are thicker than acrylics and therefore are great for use in high traffic areas. They are also very well suited to trim work both inside and out.

They need more than a shake before use though and often require the addition of thinners, therefore when it comes to disposing of your old cans and brushes you cannot, or should not simply toss them in the garbage. They are considered hazardous waste and as such should be disposed of correctly. This applies to brushes too as they can only be properly cleaned with the aid of thinners or turpentine.

Enamel paints can contribute to toxicity levels, yet because of their higher pigment content often provide a wonderful look and feel.

2. Acrylics
Acrylics on the other hand are more flexible and offer a consistent drying time between applications, are easier to clean and have lower toxicity levels. They also appear to be more stable than enamel paints with regard to cracking, oxidising or aging. Another great benefit of acrylic paints is that they offer higher levels of versatility as they allow the application of a host of other mediums on top, once dry.

Acrylics are easier to clean up afterwards, have fewer odours when applied, resist fading and mildew and are good choices for metal surfaces. They are easy to apply and quick to dry and brushes are easily cleaned using just water. They are well suited for interior applications but can also be used optimally outdoors. They are safe to have around children and pets.

Acrylics are fast drying, can be diluted with water and once dry become extremely water-resistant. They come in high-gloss finishes right down to matte finishes, each of which is dictated by the amount of pigment added. Matting agents when added create a dull finish.

3. PVA
PVA has fantastic emulsifying or adhesive properties and when introduced to paint provides high resistance to oil, greases or solvents. PVA is without odour and is non-toxic. It is strong yet flexible yet when faced with high humidity can be susceptible to moisture, yet while reducing its tensile strength, increases its elasticity which reduces it susceptibility to tearing. It is 100% degradable and dissolves extremely quickly, making it an ideal agent for paints.

Primers or Base Coats

A primer is nothing more than a preparatory coat of “matte” paint applied before the final coating is applied. Apart from ensuring that that the topcoat paint adheres better, it also increases its durability as well as providing an extra level of surface protection.

Primers are traditionally used on porous surfaces such as concrete or wood, yet work just as well on many other surfaces, metals and plastics included. Priming boards such as drywall is considered standard practice in most builds as priming seals the board and prevents moisture getting through.

Primers can also be used on surfaces that cannot be 100% cleaned, on dark surfaces in readiness for a lighter top coat and especially on uneven surfaces in order to smooth them out. Primers can also be colour matched to their top coat which is especially beneficial when painting deep colours as this reduces the amount of layers needed to achieve a uniform surface colour.

A good quality “base-coat” can and often does cost as much as finish paints do as this is influenced by the quality “binder” used in their manufacture.

Matt or Gloss finish

Varnishes are nothing more than paint without the pigment. Used predominantly for wood finishing, varnishes are see-through paints that take the form of primers, sanding sealants, stains and the like. They provide a thin film that dries quickly providing a hard and durable finish and come in a range of finishes from ultra matte to high gloss. They are mostly found in enamel paints, but can also be found in some acrylics. Varnishes can also be found ranging from “matte” to “high-gloss”.