FAQs

Sancryl Chemicals Sunwet range, is an additive that helps a paint wet the substrate. It also aids in colour development and mechanical stability.

Sancryl Chemicals Celloban range is an additive that protects a paint against microbiological attack during storage.

Sancryl Chemicals Sunburst range is an agent that is used to minimize foaming during paint manufacturing, emphasis on the mixing stage. In addition, it eliminates foam during paint application and contributes to even coatings that are free of defects.

Glycol is used in a water-based coatings to improve the freeze thaw stability, improve flow, and improve open time of the paint.

Sancryl Chemicals Sungel range is added to a paint to control viscosity of the paint. Our thickeners are pH dependent and recommended for use at pH > 8.

The prime pigment used in white emulsion paints is titanium dioxide. It gives the paint its hiding power and affects the sheen, chalking, flexibility, colour retention, and scrub resistance of a coating.

A wide variety of synthetic and natural inorganic materials are used as extenders to titanium dioxide. These are fine particles of insoluble solids with poor optical properties and generally lower cost than pigments. Such as (calcium carbonate, talc, clay, mica, etc.)

A liquid or solid material responsible for binding together pigment particles to form a tough, continuous, adherent film. The binder is probably the most important ingredient because the

type of binder determines the properties of the paint. There are many types of binders – vinyl acetate, styrene acrylic pure acrylic, vinyl acetate / Veova, etc. The choice to which binder type to use is determined by paint properties required and the cost of the binder.

A solvent that acts as a temporary plasticizer to assure a good film formation at all probable application temperatures. Generally, an emulsion with high MFFT requires more coalescent than an emulsion at a low MFFT to form a continuous film at a specific temperature.

MFFT, or minimum film forming temperature is the lowest temperature required for a polymer to form a continuous film when applied to a substrate. That is, at temperatures above the MFFT, the polymer will form a continuous film, and, at temperatures below the MFFT, the polymer will not film form and instead have a powdery appearance.

An emulsion paint is described as a water-based substance that is used for aesthetic and protective purposes. It is a mixture that contains solid pigment particles suspended in liquid which when applied to a substrate and allowed to cure, a dried film is formed. This is known as a paint coating. There are various types of emulsion paints and likewise various types of coatings that are formed. This plays an important factor when deciding what type of paint, you will need to perform a certain function or be applied to a certain substrate.

Although paint is widely regarded and purely a decorative substance, it also has the function of protecting the substrate which means, the coating will be exposed to several stimuli and therefore needs to be free of defects and irregularities. As in many instances involving human application, there is always room for error and mistakes whether in or out of our control, accidents can occur and below we look at these instances and how to best eliminate the risks of them occurring as well as preventative measures.

This describes a defect in which freshly applied paint recedes from the surface leaving small crates or bare areas.

Cissing may also occur when water-thinned paints are applied over glossy or semi-gloss oil-based coatings. It can be prevented by ensuring that the surface is clean and by flatting oil-based coatings before applying water-thinned materials. When cissing has occurred, the paint must be allowed to harden before it is rubbed down and recoated. Cissing can also occur when overloading antifoam/defoamer. Care must be taken when adding additives.

This is when a paint film is marred by small particles of extraneous material such as dust, grit and bristles of brushes causing an uneven coating across the substrate.

To avoid the above occurring the applicator needs to ensure the paint itself is free from bits and grit which can form during manufacturing and packaging of paints. Before applying the paint to the substrate, the substrate needs to be free of dust and dirt. Brushes need to be inspected to ensure they are of proper quality before use. After use, the bucket/packaging must be sealed/closed properly to ensure no air gets in as this can cause the paint to film -form inside the bucket and when agitated, will cause bits in the paint.

If for some instance the paint of the substrate is showing signs if bittiness, then the applicator can rub down the coating once it has completely cured and new fresh paint can be applied, keeping in mind the recommendations above.

The failure of a paint system to hide or obliterate the colour of the original surface or the previous paint.

It may be caused by applying too few coats, using an undercoat of unsuitable colour, excessive spreading, or uneven application of the paint. Over thinning of the paint and failure to incorporate settled pigment by thorough stirring are other causes.  Particle size distribution of the paint can also cause low hiding power therefore it is important to ensure grind time during manufacture is adequate.

To remedy the defect, it is necessary to apply further coats, avoiding any earlier faults in thinning, stirring or application. It is also important to note the quality of paint used during application as the cheaper paints use less pigment during manufacture to obtain low costs. Before application of the paint, it is important to check that the paint has not separated or settled and ensure adequate mixing is given.

Fading is the decrease in the intensity of colour of a coating.

Fading is the gradual loss of colour of one or more pigments resulting in lightening of the surface. it often goes with chalking, so when you have chalk in sight, fading is expected to follow. This defect is most prevalent on dark-coloured substrates since these tend to absorb more heat than lighter ones.

Fading is a natural process and will occur over time on all coatings. It may be induced by many factors which include, prolonged exposure to sunlight, sudden changes in temperature, surface alkali, chemical cleaning of substrates, adding unnecessary amounts of liquid colorant when tinting a white base as well as applying too much paint resulting in abnormal film thickness.

In general, organic pigments and low-cost pigments will tend to fade more than those that are inorganic. Also, certain pigments which are used in very small quantities in the color mix, tend to fade more the larger quantity pigments in the coatings. This is more so when liquid colorants are used, instead of powders. More expensive paints, especially those prepared for exterior exposure will resist fading more than low-cost paints. Weather conditions of leaching water, alkali seepage, strong sunlight and variances of shade and sunlight on wall may also contribute towards irregular fading. To prevent fading, weather resistant pigments should be used in manufacturing. When the coating has already experienced fading, the entire surface will have to be cleaned thoroughly to remove all contaminants before a new fresh paint can be applied. The general method for exterior substrates is high pressure cleaning thereafter you can prepare the surface as appropriate before painting.

This occurs when there is migration of colour from the previous coat through the new freshly applied top-coat of a substrate. This defect mostly occurs when a light top-coat is applied to a dark undercoat. The most common instances are when applying over red or maroon type paints due to the organic pigments used in manufacturing that are not resistant to solvents.

If a previous coating can be removed of a substrate before a new fresh paint is applied, it is advisable to do so. Bleeding caused by metallic inks in wallcoverings can usually be prevented by applying an alkali resistant primer as a sealer although it is still better to remove the coating altogether. Alkali resistant primers are also effective in preventing bleeding from tobacco residue.

Bleeding may not become evident until sometime after the new paint has been applied and may not be practicable to then remove the coating and deal with the problem at its source. In instances such as these, the most appropriate manner to deal with it is to apply a sealer or primer and thereafter further top coats. This will provide the best remedy.

Blistering are defects in which swelling of the paint occurs.

Essentially, blistering is a form of localized loss of adhesion of a flexible paint film. Moisture beneath the coating is the most common cause of blistering. It can also form if the substrate isn’t dried or cleaned properly before application, painting over oil paint surfaces or excessive film thickness.

Blistering can be avoided by using porous emulsion paints rather than non-porous oil based or enamel paints. You can also clean surfaces properly using a solvent ensuring the substrate is grease/oil free and allowing solvent to evaporate especially before performing a recoat. It is important to check that the paint you are using is compatible with the substrate.

If a coating has already badly blistered, it must be stripped and if the root cause is moisture, sufficient drying time must be allowed before a coating is applied. In some cases, isolated blisters can usually be removed and filled before a new overall coat can be applied.

This refers to the powdery residues formed on a paint finish when the surface begins to erode from exposure to weather.

Chalking generally occurs with time and log exposures to sunlight and it is a natural degradation of paint films. It can also occur with paints that has a high PVC (High filler and low emulsion binder) and when applied over porous surfaces that has been insufficiently sealed.

Chalking can be avoided by ensuring the substrate is sealed properly using a primer before a top coat is applied. It is also important to note the type of paint and its recommended use and quality beforehand. Applying at the correct spread rate is also important. For coatings that have already experienced chalking, the residues can usually be removed using damp cloths revealing a sound surface coating. If new fresh coating is applied over the existing coat without proper cleaning, problems are likely to occur.

This defect is a series of irregular cracks in the coating.

All forms of cracking are indicative of stresses within the coating system which is not sufficiently flexible to withstand. This may be due to aging and embrittlement of the system, movement and application of hard coatings over previously softer coatings.

To prevent cracking, the simplest way is to use a flexible paint or ensure paints have adequate coalescents in their manufacture.  Before applying a top coat, it is important to ensure the initial coat is completely cured. When cracking has already been exhibited by the coating, the coating must be completely cleaned before applying new fresh paint, keeping in mind the points above.

The detachment of a coating from the substrate is known as flaking.

The causes can be varied, for example the defect could be caused by efflorescence or the migration of soluble salts to the paint-media interface which can cause the paint to be forced off the surface. As with blistering, moisture beneath the paint or varnish film is a frequent cause of flaking as is the application of paint to powdery or friable surfaces and previous coatings. Dirt, oil, grease and polish residues on the surface impair adhesion and may result in flaking.

Excessive movement of the substrate, e.g. at joints in woodwork, may impose stresses on the paint film causing cracking, and ultimately flaking.

Small areas of flaking paint can often be dealt with by removing the loose material back to a firm edge, touching-in and bringing forward as necessary, then recoating. If the flaking is extensive or the overall adhesion of the system is doubtful, the surface should be stripped completely before repainting.

Adhesion refers to the forces of attraction between the coating and its substrate.

An adhesion failure appears as a paint that is flaking off because it failed to stick to either the substrate or a prior coating (if there was one). It can be caused by surface contamination, condensation on the substrate, applying two different coating products that are incompatible or by exceeding the overcoating time. Other coating failures are sometimes mistakenly called adhesion failures, but strictly speaking these are not a proper use of the term. An adhesion failure occurs when the chemical bond is broken between the coating and the substrate at the bonding interface. To be a true adhesion failure, the bond must not be broken due to other conditions such as abrasion, impact or underlying corrosion.

To avoid loss of adhesion in coatings you must ensure a good anchor pattern exists on the substrate, and if needed increase the surface profile by sanding or abrasive blasting. The surface to be coated must be properly prepared so that it is free of moisture, dust, dirt, old coatings or any other contaminants such as grease, wax or oil. Follow the manufacturer’s guidelines and apply secondary coatings only during the specified time window. Allow the coating to properly cure according to the manufacturer’s recommendations.

New plaster, rendering, brickwork and similar materials may contain soluble salts which, as the substrate dries out, are brought to the surface where they crystallise as a thin, hard film or a profuse, fluffy growth.

Efflorescence may also occur on aged surfaces if they again become wet, e.g. because of leaks or overflows. The fluffy type of efflorescence may disrupt paint coatings, particularly the relatively impermeable types / or low PVC types, if they are applied before the substrate has dried out and the growth has ceased. High PVC emulsion paints may permit the salts to pass through the film with relatively little physical damage, but they may affect its colour or appearance.

The best ways to inhibit this from occurring is to pressure clean the substrate before application, ensure dry brushes are used and refrain from painting freshly plastered walls. If efflorescence has already occurred, should be removed with a dry, coarse cloth at intervals of 7 – 14 days and painting should be deferred until the growth ceases. When efflorescence has disrupted a paint film, the affected area should be stripped and repainting delayed until it is clear and the efflorescence has stopped.

Mould is a plant growth that requires moisture, the presence of food and the correct temperature for growth.

The growth of mould on a paint film causes severe discoloration. The defect can occur on most types of paint but is most prevalent in bathrooms, kitchens and exterior walls that are in shady positions. The paints that are most susceptible are soft oil-based paints or varnishes and emulsions, especially if they are low gloss where dirt can be trapped in the film.

Often the mould growth can be killed and colour removed by washing with dilute sodium hypochlorite solution taking due care as this preparation is alkaline. Safety glasses and gloves must be worn.

Before repainting, susceptible surfaces should be prepared with anti-mould preparations and by using either paints prepared with mould inhibiting pigments, or by using high gloss finishes. In extreme cases it may be necessary to remove the high humidity in the room by using exhaust fans.

Contamination of many surfaces with water, soot, smoke and tobacco can result in colour coming through paint surfaces to cause stains and streaks. Excess moisture inside your home can cause water streaks on interior walls and ceilings.

Substrates can accumulate dirt. Streak marks can be formed when the dirt gets washed down vertical painted walls. Yellowish brown stains are a result of moisture present. Formation of streaks and stains can be an indication of a waterproofing problems in other parts of the structure/building e.g. faulty gutters, leaking roofs, improper ventilation, areas with big trees creating shade and higher moisture content, falling tree sap, etc.

Stains caused by water will leave a tide mark/streak and after drying, the paint around the stain can be removed and the surface repainted. If the surface may become damp again, remove the source of the water. Patches of soot or smoke should be removed before coating. Use of an insulating paint before the final coat can help. Nicotine should be removed with an alkaline cleaner (bleach) before coating. Remember to wash off all the alkali before attempting to paint. It is also wise to ensure there is proper ventilation in the area to ensure no build-up of moisture and to ensure there are no water leaks or faulty gutters on roofs.