Tips & Hacks!


Defect – Brush marks

Causes
  • Improper flow of the applied coating.
  • Applying paint at high viscosity
  • Continued application over a long period.
  • Application with a dirty, clogged brush.
Prevention
  • Apply paint at the correct recommended viscosity using correct thinner

  • Apply paint quickly and evenly

  • Use clean good quality brushes
Cure
  • After the coat has dried, rub down the surface to smooth and uniform level and carefully recoat.
  • A Defect – Chalking.

Defect – Chalking
Causes
  • Under bound coatings chalk on exposure to weathering

  • Paints applied over insufficiently sealed, porous surfaces

  • Paints not correctly pigmented for specific end use
Prevention
  • Ensure complete sealing of porous surfaces

  • Avoid using inferior quality paints

  • Do not mix undercoats into finishes
Cure
  • The fine powdery film can be removed by wiping and apply a fresh good quality top coat

Defect – Sagging
Causes
  • Applying coatings at incorrect viscosities, film thickness

  • Using improper thinner for thinning
Prevention
  • Care should be taken to apply coats at recommended film thickness and application viscosities
Cure
  • Rub down the sagging parts and recoat carefully

Defect – Drying not proper
Causes
  • Application in unsuitable weather (frosty, cold, humid etc.)

  • Improper ventilation Applied over oily, greasy, or unhardened surfaces
  • Using long stored paints in which there are chances that the driers are absorbed by pigments making them non functional.
Prevention
  • Always apply in a dry, warm climate with sufficient air circulation
  • Ensure proper cleaning of the surface free from oil grease
  • Add slight excess of cobalt and lead drier

Defect – Efflorescence
Causes
  • Soluble salts from the substrate brought to the surface by solutions of fresh coats

Prevention
  • Do not apply coats on damp moist or freshly plastered surfaces, highly alkaline plasters
Cure
  • AWipe off the deposited salts completely from the surface and ensure no more deposition before recoating

Defect — Flaking
Causes
  • Surfaces having non uniform expansion and contraction causing undue stress
  • Application over powdery or chalking undercoats
  • Application over dirty greasy surfaces

Prevention
  • Ensure that all surfaces are thoroughly clean and dry surfaces.
  • Use the recommended primers and undercoats.
Cure
  • ARemove all loose paint by scraping and sanding

Defect — Peeling
Causes
  • Subsequent coats before the previous coat has cured
  • Application of paints containing strong solvents which softens the previous coat

Prevention
  • Ensure that the previous coats are thoroughly dried
  • The primer, undercoat and top coat should be entirely compatible
Cure
  • Scrap the entire disintegrated system and rework freshly

Defect – Loss of gloss
Causes
  • Application on greasy, oily surfaces
  • Using inferior quality non compatible thinners
  • Applying over badly prepared porous surfaces and inferior uncured undercoats.

Prevention
  • Ensure that the surface is well prepared, free from dirt, oil, grease etc
  • Apply over good quality primer undercoat and under warm dry atmosphere.
Cure
  • Add small proportion of cobalt drier or antiskin agents
  • After flattening the surface, apply a fresh coat of top coat of clear varnish.

Defect – Low coverage
Causes
  • Thinning beyond recommended volume.
  • Recommendation wrt number of coats not followed
  • Surface preparation i.e. primer / putty not as advised
Remedy
  • Adopt painting guidelines as specified in the product literature / container
Cure
  • Add small proportion of cobalt drier or antiskin agents
  • After flattening the surface, apply a fresh coat of top coat of clear varnish.