COMMON PAINT DEFECTS AND REMEDIES
Many problems can occur after painting. Sometimes, they occur simultaneously during painting. Understanding the causes of some of these defects can make the paint job easier. Here are some common paint defects and their solutions:
Blistering: Blistering or Swelling of paint is caused due to the trapping of air, moisture or solvent between the surface and the paint film. The solution- Remove any unstable paint films and allow the wall to dry thoroughly. Then repaint with a recommended paint. Avoid painting under direct sunlight.
Bittiness: Bittiness is caused by dirt from the atmosphere or the surface or from brushes that are inadequately cleaned or due to bits of dried-up paint that gets stirred in. The Solution- Use clean brushes and paint on clean surface and strain the paint through a cloth before use.
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 Solution - The surface should be brushed to remove algae / fungus growth, dirt and dust. Apply /spry the are with anti Algae solution (found in your hardware / supermarket store), or using mixture of bleach and water (50% bleach 50% water). High-pressure wash to remove any residue and 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 Solution - Ensure paint of the right viscosity is applied using 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 Solution - 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 the wall to dry thoroughly, and repaint with a recommended paint. Make sure the paint is not adulterated with foreign materials.
Cissing: Cissing or tiny craters are caused by oily or greasy surface/due to water based paints being applied over glossy or smooth enamel paints. The Solution- Clean the surface thoroughly with soap solution and water. Roughen the enamel paint with Sandpaper and/or use an undercoat/primer before applying top coat.
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 Solution- Give a long time gap between plastering and painting (about 6 months) Use paint with a porous film like emulsions and distempers.
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 Solution- Clean 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 Solution - Repair water seepage. Make sure the surface is dry before painting and apply an alkaline-resistant or oil-based paint.
Flaking: Flaking-off of paint film is due to improper application of primer coat over putty, and not being completely covered. It can be due to application of paint on insufficiently dry surfaces. It can also be due to shrinkage or expansion of a surface causing the paint film to move. The Solution- 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 Solution- Apply an extra coat of primer or sealer.
Peeling: Peeling is caused by moisture on the wall, poor surface preparation or using an incorrect painting system. This defect happens on walls as well as wood or metal surfaces.
The solution for Walls -Check and repair water seepage. Ensure walls are dry before painting. Use an alkali-resistant basecoat or sealer. Patch surface defects with external grade filler.
The solution for Wood - Prime wood before painting, sand surface and clean off dust.
The solution for Metal - Remove all paint from metal before re-painting. Prime 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 or storing for too long or under too much heat or faulty thinning. The Solution- Avoid storing in hot locations for long periods. Store in accordance with the manufacturer’s recommendations. 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 to happen. The Solution- Avoid applying too much paint. Make sure no paint accumulates around 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 Solution-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.
Alligatoring and Checking
"Alligatoring" is a failure in the paint film where it takes on a cracking pattern of deep relief resembling a reptile's skin, such as that of an alligator. "Checking" is a similar failure but is less severe and is characterized by long, fairly evenly spaced cracks in the paint film having shallow relief or depth. Occasionally checking may become severe in some areas and a deeper crack or split in the paint will occur.
Potential Causes (Alligatoring):
Potential Causes (Checking):