01Surface preparation7 Grades.ISO 8501-1 grades of steel surface cleanlinessView the grades
02Coating defects25 Defects.Every applicator and inspector must recognise themView the defects
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03Inspection & testing30 Tests.Inspection and test types on Sicon Group projectsView the tests
Roof Coating Standards: Preparation, Defects & Inspection
The standards behind every Sicon Group coating project: the ISO 8501-1 grades of steel surface cleanliness, the 25 paint and coating defects every applicator and inspector must recognise, and the 30 inspection and test types applied on our projects.
ISO 8501-1 Surface Preparation Standards
Grades of Steel Surface Cleanliness | Sicon Group Coating Standard
grades
Thorough Hand & Power Tool Cleaning
Loose mill scale, rust and old coatings removed. Surface left with a faint metallic sheen.
Very Thorough Hand & Power Tool Cleaning
As St 2 but far more thorough. The surface shows a pronounced metallic sheen.
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Light Blast Cleaning (Brush-Off)
Loose contaminants removed only. Tightly adherent scale and rust may remain.
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Thorough Blast Cleaning (Commercial)
Almost all contamination removed; light shadows and staining may remain.
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Very Thorough Blast Cleaning (Near-White)
Only slight shadows or slight discolouration permitted.
Sicon standard for most projects
Blast Cleaning to White Metal
Free of all visible contamination. A uniform metallic finish, used for severe exposure.
Flame Cleaning
Heat used to remove scale and rust. Rarely specified on modern coating systems.
Key Points
Common Paint & Coating Defects
25 Defects Every Applicator & Inspector Must Recognise | Sicon Group
defects
Tap a photo to see it larger.
Runs & Sags
Paint flows down, forming runs.
Orange Peel
Dimpled, orange-like texture.
Pinholes
Small holes in the dry film.
Blistering
Blisters rise off the surface.
Cracking
Cracks through to the substrate.
Checking
Small cracks in the film only.
Crazing
Fine hairline topcoat cracks.
Peeling
Paint lifts in large sheets.
Flaking
Paint flakes off in chips.
Chalking
Surface becomes powdery.
Wrinkling
Film wrinkles while drying.
Fish Eyes
Craters from contamination.
Dry Spray
Rough, partially dried paint.
Overspray
Mist on non-target areas.
Holidays
Missed areas, no coverage.
Mud Cracking
Cracks like dried mud.
Lifting
An earlier coat lifts and wrinkles under a new one.
Bleeding
Colour stains the topcoat.
Discolouration
Colour change or unevenness.
Rust Staining
Rust stains on paintwork.
Solvent Popping
Trapped solvent bubbles.
Contamination
Dirt, dust or oil in the film.
Cratering
Coating pulls back in craters.
Poor Adhesion
Peels or scratches off.
Underfilm Corrosion
Corrosion under the film.
Record every defect with a photo, location and date before repair.
Painting & Coating Inspection
30 Inspection & Test Types Applied on Sicon Group Projects
test types
Proper inspection ensures high coating quality, long asset life and lasting protection from corrosion.
Download the Sicon Group Coating Standard
All three sheets in one PDF, for specifiers, site managers and anyone checking a coating proposal.