“Measurement of Dry Coating Thickness with magnetic Gages” HOW MUCH IS ENOUGH? Statistical method to determine the minimum number of readings required. SSPC-PA 2 – Measurement of Dry Paint Thickness with Magnetic Gauges Procedures to Measure Dry Film Thickness of Nonmagnetic Coatings over Magnetic Substrates…
Category: PAINTING & COATING
Terms and definitions of painting
Some of the main definitions applicable to a painting process are defined below: Corrosion Ability of an environment to cause corrosion in a given system Curing Hardening of the liquid paint by heat or by chemical reaction Curing Agent Is the component which produces the…
VISCOMETER
A fluid’s resistance to flow is its viscosity—the ratio of force required to overcome internal friction between layers of fluid (shearing stress) to the change in speed between layers of fluid (velocity gradient). Many quality control measures are based on viscosity. For example, paint needs to…
INSULATION
What is Aerogel insulation? Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas. The result is a solid with extremely low density and low thermal conductivity. … Carbon aerogels…
Airless Sprayer Tip Sizing Guide
Picking the correct tip and size is essential for a quality finish and ease of use. This may seem a bit confusing or complicated at first but once you understand it, picking the right tip is not rocket science and can save you time and…
ADDITIONAL TEST IN GALVANIZED STEEL
Every hot-dip galvanized steel part is inspected for coating thickness and visually for appearance and finish. However, there are a few additional tests that may be conducted on certain types of parts or when there is a question or concern about a specific item. Adherence…
Test Methods for Coating Adhesion
For coatings to perform satisfactorily, they must adhere to the substrates on which they are applied. A variety of recognized methods can be used to determine how well a coating is bonded to the substrate. Commonly used measuring techniques are performed with a knife or…
Holiday Testing
Holiday testing is a non-destructive test method applied on protective coatings to detect unacceptable discontinuities such as pinholes and voids. The test involves checking an electric circuit to see if current flows to complete the circuit. This testing is used to find coating film discontinuities…
Sags/Runs
Downward movement of paint soon after application on vertical surfaces Common Causes Over application Excessive thinning Poor workmanship Remediation While wet, sags/runs should be smoothed with a paint brush If dry, abrade, clean, and apply spot coat
BLUSH
Haze or oily residue on the surface of a coating Common Causes High humidity or cold temperatures during application Curing stages of an epoxy Intensified by cool temperatures and increased coating thickness Remediation Blush will effect adhesion of topcoat If blush is detected (not easy…
Blistering
Coating lifting from the underlying substrate Common Causes Contamination on the substrate Oils and greases Soluble Salts (osmotic blistering) Solvent entrapment Remediation Ensure correct surface preparation and application Soluble salt testing
Delamination
Results from loss of adhesion between the substrate and coating OR between coats. Common Causes : Poor surface preparation Intercoat cleanliness Exceeding overcoating times Incompatibility of topcoat and primer Remediation : Area with poor adhesion must be completely removed and the cause should be evaluated…