What are Epoxy Coatings?

Epoxies are thermoset plastics made by a chemical reaction of 2 or more elements that provide a hard and chemically resistant surface. Cured epoxy coatings make extremely durable finishes coupled with excellent adhesion properties. One of the most obvious uses for epoxy coatings is to provide corrosion prevention for steel parts; typically pipework, pump and valve bodies, support steelwork and floor gratings.

Types of Epoxies

There are differing types of epoxies; Bis-A Epoxy, Bis-F Epoxy and Novolac Epoxy, each with differing characteristics.

Table 1: Properties

Typical Performance Property Bis-A Epoxy Bis-F Epoxy Novolac Epoxy
Adhesion H H H
UV Protection L L L
Abrasion Resistance H H H
Crystallisation L H H
Moisture Tolerance H H H
Heat Resistance L M H
Chemical Resistance M M H
Sulfuric Acid L M H
Acetone L M H
Methanol L M H
Sodium Hydroxide H H H
Organic Acids L L H

H – Highest, M – Medium, L – Lowest
(Source: J.D Durig – “Comparisons of Epoxy Technology for Protective Coatings and Linings in Wastewater Facilities”)

Most epoxies used as a coating system come as 50–55% solids content pre-dispersed in water and co-solvent. Due to this, there is a need to deal with liberated volatile organic compounds (VOC’s) at the point of application, potentially a costly exercise in terms of plant, equipment and space for placement.

Fusion Bonded Epoxies

100% solids epoxy systems were developed to eliminate VOC’s and water. No water and no co-solvents required, thus meaning the coating is cured rather than dried. This type of epoxy (in powder form) leads to the thickest type of epoxy coatings in use today; 10 mils/254 µm – 30 mils/762 µm and thicker. They tend to be more abrasion resistant, and provide excellent durability, with Northpoint’s FBE coating solutions delivering a 60 year Design Life.

There are many benefits to a 100% solids epoxy polymeric system:

  • Removes the need for solvents
  • Provides a thicker coating
  • Coating is odourless with very little shrinkage
  • Application times reduced because of the exothermic reaction
  • Crosslinking density is higher than waterborne epoxies meaning their mechanical properties are better

Table 2: Comparison of Epoxy Systems

Attribute Waterborne/Co-Solvent 100% Solids
VOC Content Low Zero
Coating Thickness Less 10X Typical
Requirement for Multiple Layers Yes None
Used as a Primer for Multiple Layer Systems No Yes
Typical Mean Thickness 3 mils/76.2 µm 30 mils/762 µm
Cure Time Longer (days) Less (hours)
Pot Life Longer Zero
Industrial Applications Light Heavy
Durability Good Excellent
Chemical Resistance Good Excellent
Abrasion Resistance Good Excellent
UV Stability Poor Poor


The Northpoint Difference

Northpoint offers 100% solid epoxy coatings (FBE) in Aqua/Green, Red and Blue with either Drinking Water Inspectorate (DWI) Approvals or Water Regulations Advisory Scheme (WRAS) Approvals, in addition to Liquid Epoxy coatings and linings where appropriate to NORSOK M-501 Standards. Northpoint can deliver epoxy coating systems that meet the specifications of SaudiAramco, Kuwaiti Oil Company, ExxonMobil and other major oil and gas companies.

Northpoint has the expertise to assist with pre-qualification, Project Quality Plans (PQP’s) and Inspection Test Plans (ITP’s). The finished coating can be provided with a document package that includes an ISO 10204 Document of Compliance signed off by NACE III and II Coatings Inspectors.

With over 40 years of organisational experience and an abundance of expertise from our specialist team, Northpoint can provide a bespoke solution to meet even the most demanding environments. A combination of knowledge and expertise has allowed Northpoint to establish a strong reputation as a trusted supplier to customers across the UK and internationally. Contact us today for a quotation or to discuss your requirements.

Article written by Philip Dawson, Technical Consultant, Northpoint Ltd.