1.2. Surface Preparation:
Surface should be prepared in accordance with the recommendations of the paint coating specifications and product data sheets.
1.2.1. When tested surfaces are shown to contain more than 20 μg/cm2 of Chlorides, this surface shall be high pressure water cleaned (HPWC) with clean fresh water and Chlor-RID as per the data sheet.
1.2.2. Checking the salt and Chloride content on the surface using salt detection kit # 134 elcometer, Chlorides content on the cleaned surfaces should not exceed the required specification.
1.2.3. Cleaned surfaces may have to be washed with the freshwater /Chlor-RID wash solution more than once until this limit of Chlorides is reached.
1.2.4. Since most of our surfaces are subjected to aggressive and severe conditions, the blasting standard required and which will be achieved is Sa-2.5 (NACE 2/sspc-sp 10-63), or (ISO 8501 -1 Sa- 2 1/2) "near white"blasting cleaning using an abrasive media. No recycle, "Clemco"American made blasters, 200 liter capacity, with remote control and breathing apparatus are going to be used
1.2.5. Surface profile 2 - 4 mills RMS is to be obtained - Elcometer 123 surface profile gauge to be used.
1.2.6. Weld seams, metal silvers, sharp edges, weld spatters will be removed, using power tools to provide a uniform, non-polished surface.Sharp edges to be rounded by grinding to approx. 2 mm radius, as paint coatings tend to run-away from sharp edges, resulting in thin coating and reduced protection.The usage of power wire impact tools, power wire brushes, power wire sanders should physically kept very limited because it may lead to the smoothing and polishing of the metal surface and finally destroying the surface profile - peaks and valleys - that will reduce the key for the subsequent paint coating.
1.2.7. Blasted surfaces shall be coated with one coat of primer during
the same day that blasting was done and before any visible deterioration occurs.
1.2.8. If before painting the surfaces become contaminated in anyway or oxidation has occurred, surface preparation is to be repeated.
1.2.9. All abrasive and dust from blasting operation shall be removed
from surfaces before painting application, by brushing and sweeping.
1.3. Painting
The success of any paint application is governed by a number of
parameters including:
• Surface preparation.
• Film thickness application.
• Methods of application.
• Condition during application.
Painting shall be carefully, neatly and expertly done in accordance with the best ship building practice of the trade by skilled and competent painters, who are thoroughly familiar with the type of work they are performing on the drilling rigs.
1.3.1. Applying the recommended number of coats to achieve the
required thickness, using "GRECO" airless spray guns "King 68:1" with the proper nozzles
1.3.2. All coatings materials will be applied in strict accordance with
coating manufacturer guide lines or data sheets, regarding surface
temp., ambient temp., relative humidity, drying time, recoat time,
handling time… etc.
1.3.3. Stripe coating of each paint stage will - where necessary - be
performed in order to maintain the required DFT.
1.3.4. Wet film thickness WFT - will be checked after the application of each coat using a comb gauge, elcometer 112 or elcometer 120 wet film wheel, followed by a DFT check when dry, using an electronic coating thickness meter, elcometer 345.
1.3.5 Stitch welds, footholds, narrow gaps, where corrosion can be
initiated and later expanded into areas generally well protected, shall be treated using the recommended putty.