While painting or some time after the painting, you may notice some defects in the painting. Understanding the causes of these defects can prepare you well enough, before you start the painting process and make the job easier. Here are some common paint defects and the solutions to remedy them:
Blistering: Blistering or Swelling of paint is caused due to trapping of air, moisture or solvent between the surface and the paint film. The remedy is to remove any unstable paint films. Allow the wall to dry thoroughly, and repaint with a recommended paint. Also, avoid painting under direct sunlight
Algae/Fungus growth: Algae and fungus can grow when the surface is continually damp and dirty. Insufficient fungicide/ algaecide in the paint can also worsen the situation.The Remedy is to remove algae / fungus by high-pressure washing. Wash again to remove any residue. Allow the wall to dry before applying with recommended paint.
Brush marks: Brush marks are caused due to under-thinning of paints or due to poor application of the final coat of paint or due to poor quality brush. The Remedy is to ensure the paint is applied using the right viscosity and a good brush.
Chipping: Chipping of paint film is due to excessive use of putty or due to very thick coat of paint or defective surfaces. The Remedy is to regulate the use of putty and paint.
Chalking: Chalking occurs when ultraviolet rays cause the paint binder to disintegrate. It can happen when interior paints are used for exterior surfaces. The solution- Remove any unstable paint films. Allow wall to dry thoroughly, and repaint with recommended paint. Make sure paint is not adulterated with foreign materials.
Cissing: Cissing or tiny craters are caused by oily or greasy surface or due to water based paints being applied over gloosy or smooth enamel paints. The Remedy is to clean the surface thoroughly with soap solution and water. Roughen enamel paint with Sandpaper or use a barrier coat of matt primer.
Cracking: This is caused when the paint or varnish is applied over a base layer of different elasticity before it has been given enough time to cure (which can take up to a month). For example, two separate brands of varnish may react with each other and form cracks. The Remedy is to allow the surface to dry fully and then rub it down to make it ready for repainting. However, you could consider leaving the cracking visible. It is a very popular ageing technique.
Drips: Drips or nibs in the dried paint surface are usually pure lapses in technique. The Remedy is to rub the dried drips away with fine sandpaper and re-paint the area. On high gloss finishes you may need to apply a final coat over the entire area to disguise the patch where you rubbed.
Efflorescence: Efforescence or formation of white powdery deposit on walls after painting is caused due to salts present in the building material like brick and mortar, which surface later on. The Remedy is to give a long time gap between plastering and painting (about 6 months including one monsoon) Use paint with a porous film like emulsions and distempers.
Grinning: If the previous colour shows through the finishing coat, it is because the base was too dark or the paint was too thin or badly applied. The Remedy is to just paint over.
Loss of gloss: Loss of gloss is caused due to poor surface preparation or due to presence of oil or due to over thinning of paint. The Remedy is to clean the surface thoroughly and take all recommended steps for surface preparation.
Discolouration: After paint is applied, it may fade or discolour. This is caused by particles in the wall reacting with the paint when it is drying. Discolouration could also be caused by water seepage, or by contaminants in metal or wood. The Remedy is to repair water seepage. Make sure the surface is dry before painting. And apply an alkaline-resistant or oil-based paint.
The remedy for wood is to prime wood before painting, sand the surface and clean off dust.
The remedy for metal is to remove all paint from metal before re-painting. Prime the surface and re-coat with suitable paint.
Sheariness: Patches of uneven sheen on flat- or low-sheen finishes are caused by painting on too porous a surface, causing uneven drying. The Remedy is to use a large brush or roller to cover the area quickly or a sealer undercoat.
Yellowing: White paint will gradually yellow because it receives little light - such as inside cupboards or behind pictures. The Remedy is to use non-yellowing whites.
Flaking: Flaking-off of paint film is due to improper application of primer coat over putty, and not being completely covered. It can also be due to application of paint on insufficiently dry surfaces or due to shrinkage or expansion of a surface causing the paint film to move. The Remedy is to ensure that there are no gaps in covering putty with primer coat. Also ensure that the surface is dry and clean.
Patchiness: Patchiness or uneven finish is caused due to the highly absorbent nature of the surface. The Remedy is to apply an extra coat of primer or use well-sealer.
Peeling: Peeling is caused by moisture on the wall, poor surface preparation or using the incorrect painting system. This defect happens on walls as well as wood or metal surfaces.
The remedy for walls is to check and repair water seepage. Ensure the walls are dry before painting. And use an alkali-resistant basecoat or sealer. Patch surface defects with putty.The remedy for wood is to prime wood before painting, sand the surface and clean off dust.
The remedy for metal is to remove all paint from metal before re-painting. Prime the surface and re-coat with suitable paint.
Sagging: Sagging happens when the paint droops downward after being applied on the surface. It is caused by the pigment separating from the paint and settling at the bottom of the container and comes as a result of insufficient stirring or shaking during storage, storing for too long or under too much heat, or faulty thinning. The Remedy is to avoid storing in hot locations for long periods. Store in accordance with the manufacturer's recommendations and thin only with appropriate recommended thinners.
Wrinkling: Wrinkling happens when the paint forms film-like undulating waves. Applying too much paint, or drying during high temperatures, or painting on a topcoat before the undercoat is dry can cause this defect. The Remedy is to avoid applying too much paint. Make sure no paint accumulates round bolts, rivets, etc. Wait until each coat dries before you re-coat.
Slow drying: Non-drying or slow drying of paint film is caused due to humidity, poor air circulation, low temperature or presence of oil or grease on the surface or due to alkalinity of the surface. The Remedy is to reduce the impact of atmospheric conditions to the extent possible; Scrub oil or grease off with a rag soaked in white spirit and wash with water and soap.
Sheariness: Patches of uneven sheen on flat- or low-sheen finishes are caused by painting on too porous a surface, causing uneven drying. The Remedy is to use a large brush or roller to cover the area quickly or a sealer undercoat.Yellowing: White paint will gradually yellow because it receives little light - such as inside cupboards or behind pictures. The Remedy is to use non-yellowing whites.
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