How To Avoid Pinholes In Paints, Coatings & Linings

Are you concerned about pinholes in the paint, coating or lining of your vessel, tank, pipeline or industrial equipment? These defects can have a catastrophic effect on the underlying substrate if not located and rectified prior to being placed in service. Here we look into the causes and prevention of pinholes.

Causes of Pinholes in a Paint, Coating or Lining Film

Pinholes can be a result of any of the following:

  • Poor environmental conditions.
  • Contaminated surface prior to painting, coating or lining application.
  • Poor atomisation of the material during spray application.
  • Air escaping from a poorly constructed fabrication, seen often in incorrectly welded items.
  • Rapid solvent release from within a paint, coating or lining film.
  • Use of incorrect or incompatible solvents during thinning.
  • Thin film coverage where the material has not fully coalesced.


Prevention Of Pinholes

With the above causes in mind, pinholes can be avoided by following good painting, coating and lining practices which include but are not limited to:

1. Environmental Control – High humidity and high ambient temperatures are a common cause of pinholes. Ensure the environmental conditions and parameters detailed within the supplier data sheets are fully adhered to.

2. Surface Contamination – An unclean or poorly prepared surface is a common culprit when it comes to sources of contamination. This can be easily avoided by use of a competent surface preparation specialist and following the correct Quality Assurance Procedures.

3. Equipment Maintenance & Applicator Competence – Poor atomisation can be removed by regular equipment maintenance and the use of correctly trained and experienced applicator personnel.

4. Fabrication Defects – Pinholes are often found in poorly constructed weld seams and as a consequence of punch marks or pitted substrate. Compliance with fabrication standards is essential.

5. Insufficient Film Thickness – Pinholes are sometimes the result of under application where the lining film has not fully coalesced and therefore does not provide a fully formed film.


The Solution To Avoiding Pinholes In Paints, Coatings & Linings

Use of a competent, experienced, accredited and verified contractor partner such as KUE Group is vital. An expert team will be able to advise and assist on the specification, surface preparation, environmental control, application competence and all QHSE requirements for lined equipment.

To discuss your options please call 01274 721188 or contact us through our website.

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