
- •8. Inspection and control. Table of content.
- •8. Inspection and control.
- •8.1. Inspection at shop priming
- •8.2. Inspection of steel work (Pre-blasting preparation)
- •8.3. Inspection of surface preparation.
- •8.3.1. Cleanliness. Solvent cleaning, sspc-sp1.
- •Table 8.1. Methods for solvent cleaning.
- •8.3.2. The evaluation of present condition (rust grades and visual cleanliness).
- •8.3.3 Inspection of surface preparation
- •8.3.3.1. Uncoated steel
- •8.3.3.2. Previously coated steel.
- •8.3.3.3. Roughness (steel surface profile)
- •Table 8.2. Nominal value of surface profiles.
- •8.3.3.4. Abrasives for blast cleaning.
- •8.3.3.5. Water jetting
- •8.3.4. Cleanliness after surface preparation.
- •8.3.4.1. Detection of ferrous salts.
- •Figure 8.3. Detection of Ferrous salts. “Merckoquant test”: iso 8502-1, Part 1.
- •8.3.4.2. Detection of chlorides
- •8.3.4.3. Detection of all water-soluble salts.
- •Figure 8 4. The chloride concentration on a substrate may vary significantly with exposure condition and with method used for cleaning the surface.
- •8.3.4.4. Dust.
- •Figure 8.5. Assessment of dust on steel surfaces prepared for painting. Iso 8502-3
- •8.3.4.5. Welding fumes
- •8.3.4.6. Climatic conditions, iso 8502-4
- •Table 8.3. Summary of pre-treatment and cleanliness control. Checking of all surfaces
- •8.4. Inspection before and during application.
- •8.4.1. Technical Data Sheet, tds
- •8.4.2. Correct mixing and thinning
- •8.4.3. Wet film thickness (wft)
- •Climatic conditions.
- •Table 8.4. Application control: Inspection before and during the paintwork
- •8.5. Inspection after application
- •8.5.1. Dry film thickness (dft)
- •8.5.1.2. Destructive test methods.
- •8.5.1.3. Calculation of Dry-film Thickness (dft)
- •8.5.2. Curing / drying.
- •Figure 8.6. Curing test of Zinc ethyl silicate with mek. Astm. D4752-87.
- •8.5.3. Adhesion control by “Pull-off test”.
- •8.5.3.3. Cross-cut test.
- •Figure 8.7. Classification of cross-cut test.
- •8.5.4. Holiday detector
- •Table 8.5.
- •Inspection after application.
- •Table 8.5. (cont.)
- •Inspection after application.
- •8.6. Records of work and working conditions.
- •Surface preparation.
- •Cleanliness after surface preparation.
- •Mixing and thinning
8. Inspection and control. Table of content.
Section |
Title |
Page |
8.1 |
Inspection at shoppriming |
8.2 |
8.2 |
Inspection of steel work (Pre-blasting preparation) |
8.3 |
8.3 8.3.1 8.3.2
8.3.3 8.4.4 |
Inspection of surface preparation Cleanliness. Solvent cleaning. SSPS-SP1 The evaluation of present condition (Rust grades and visual cleanliness. Inspection of surface preparation Cleanliness after surface preparation |
8.4 8.4 8.5
8.6 8.11 |
8.4 8.4.1 8.4.2 8.4.3 8.4.4 |
Inspection before and during application Technical data sheet, TDS Correct mixing and thinning Wet film thickness (WFT) Climatic conditions |
8.16 8.17 8.17 8.18 8.19 |
8.5 8.5.1 8.5.2 8.5.3 8.5.4 |
Inspection after application Dry film thickness (DFT) Curing / drying Adhesion control by pull-off test Holiday detector |
8.19 8.20 8.23 8.24 8.27 |
8.6 |
Records of work and working conditions |
8.28 |
8. Inspection and control.
As mentioned in the introduction the human factor is the most critical part in achieving the specified quality for the coating system. It is therefore of major importance to carry out inspection of the work. This section of the textbook will describe what to inspect when, and the tools available for the inspector during the work. The following section “Paint failures” will describe the kind of failures one may experience and the necessary remedial actions.
During the production of a construction, inspection should be carried out at the following critical stages:
Inspection at shop-priming
Inspection of surface preparation
Inspection before and during application
Inspection after application
Each of these points is described below. Further, the inspector shall inspect / verify and document that the work is:
In accordance with the specification
In accordance with normal practice of good workmanship
In line with the paint manufacturer’s requirements for the product.
If not so, proper remedial actions must be taken and the results inspected and approved before the work proceeds.
8.1. Inspection at shop priming
In recent years there has been some discussion whether the shop primer should be allowed to remain on the steel, or to be partly or completely removed prior to further painting. Any shop primer remaining necessitates an even more thorough inspection at the shop, as the shop primer will be a part of the long-term protective paint system of the structure. Inspection at shop-priming plant includes:
Only steel with rust grade A or B (ISO 8501-1) should be used for shop priming.
Shopprimer must be applied to a shot or grit-blasted substrate with a minimum blast cleaning quality of Sa 2 ½ (ISO 8501-1).
Correct Dry Film Thickness, DFT of approximately 15 microns due to welding and cutting (as per manufacturer’s recommendation).
Satisfactory curing / drying process (no damages caused by conveyer).