Industrial Coatings
Industrial coatings are liquid paint systems, such as epoxy primers, zinc-rich primers, polyurethane topcoats and heat-resistant paints, applied to protect steel structures and equipment from corrosion, chemicals and weathering. They are specified by environment, surface preparation and dry film thickness.
What it is
A protective coating system usually has a primer for adhesion and corrosion inhibition, an intermediate build coat, and a topcoat for weathering and colour. The total dry film thickness (DFT) and surface preparation largely decide how long it lasts.
Systems are chosen for the corrosivity of the environment, from indoor dry (C1) to marine and industrial (C5) under ISO 12944, and for special needs such as high temperature, chemical splash or abrasion.
Typical applications
- Steel structures, frames and fabrications
- Tanks, vessels and pipework
- Machinery and equipment housings
- High-temperature exhausts and ovens (silicone coatings)
- Parts too large or heat-sensitive for powder coating
Suitable materials
- Structural and mild steel
- Galvanised steel
- Aluminium
- Cast iron
Points to consider
- Surface preparation matters as much as the paint; blasting to Sa 2½ gives far better life than hand cleaning.
- Specify the environment or ISO 12944 category so the right system and DFT are used.
- Liquid coatings suit very large or heat-sensitive parts that cannot go into a powder oven.
- Colour, gloss and topcoat choice should suit UV exposure; epoxies chalk outdoors unless top coated.
Frequently asked questions
What is DFT in painting?
DFT is the dry film thickness, the thickness of the cured paint, usually measured in microns. The specified DFT is key to the life of a coating system.
Should I choose powder coating or liquid paint?
Powder coating is tougher and economical for parts that fit an oven. Liquid industrial coatings suit very large, site-assembled or heat-sensitive items, and specialised systems like zinc-rich or high-temperature paint.
What does Sa 2½ mean?
It is a blast-cleaning grade under ISO 8501-1 meaning the steel is very thoroughly cleaned to near-white metal, the standard preparation for high-performance coatings.