A.S.Khanna Corrosion Science & Engineering IIT Bombay What do - - PowerPoint PPT Presentation

How to Write Paint Specifications A.S.Khanna

Corrosion Science & Engineering IIT Bombay

What do we mean by Paint Specification

• Protecting a surface with a paint coating that takes

care of the requirements of a user

• Requirements

– Chemical Resistance

• Resistance to chlorides, acids, alkalies, solvents

– Mechanical Properties

• Impact, scratch, abrasion, bond strength

– Weathering properties

• Resistance to UV, rains, snow

– Heat Resistance

• Highest Temperature a paint can resist

– Low Temperature resistance

• Lowest temperature a paint can resist

Selection Criteria

• Location

– Environment

• Mild, Urban, Coastal
• Onshore
• Offshore

– Mud line – Silent water Zone – Splash Zone

Selection Criteria … contd

• Surface Finishing Requirements

– New Surface – Old Surface

• Whether possibility of complete Cleaning
• Partial cleaning
• Application Technique

– Brush – Roller – Air Spray – Airless Spray

• Life of Coating

– Long Life – Short Life

• Cost

Type of paints

• Conventional Solvent based Paints

– Requires more time to dry – High DFT in several coats – Large recoating intervals – Chances of malpractices – tempering of resin ./ solvent composition

• Modern paints

– Solventless Paints – High DFT in single coat – Modified by Glassflake enhance life by several folds.

Ensuring Proper Raw Materials

• Initial Checking of the composition of the

paint- resin, hardener, thinner etc.

– Volume solid – Viscosity – Density

• Batch Testing of Each Batch

Performance tests – pre Qualifications

• Chemical Resistance
• Weathering
• Mechanical Properties
• Special Tests – if any

Qualified Personal

• It is now very important to properly check the

staff who are going to take the job:

– Technical Qualification of applicators / Surface preparation – Qualified Supervisor – Qualified Inspectors

• Their role must be specified and data

collected must be properly arranged and checked.

Coating Conditions

• Proper Humidity
• Proper Temperature
• Free from salt deposition
• Free from contamination by salt aerosols etc.

Environment Category as per (ISO-12944-2) Surface Preparation Required as per ISO 8501 Coating System

• No. of

Coats DFT in (μm) C 3 Non-immersion Medium Corrosion ( Temperature up to 120oC) St 2 Medium durability Primer : MIO based alkyd Top Coat : Modified Alkyd ( with urethane) 1 1 50 50 Long Durability Primer: Epoxy Mastic Top Coat – 2 Pack Aliphatic PUR 1 1 50 100 Sa 2.5 Medium Durability 2 coats of Alkyd Long Durability Primer – Zn-rich Top Coat -2 pack Aliphatic PUR 2 1 1 150 50 80 C 4 Non-immersion ( High Corrosion) Sa 2.5 Medium Durability Primer: Zn-rich epoxy Intermediate: Epoxy MIO Top Coat: 2 pack Aliphatic PUR 1 1 1 50 60 50 Long Durability Primer: Inorganic Zn- Silicate Intermediate: Epoxy MIO Top Coat: 2 pack Aliphatic PUR 1 2 1 50 150 50 C 5 Non-immersion Very High Corrosion ( Temperature up to 120oC Sa2.5 Medium Durability Primer: Inorganic Zn- Silicate Intermediate: Epoxy MIO Top Coat: 2 pack Aliphatic PUR 1 2 1 50 150 (2x75) 50 Long Durability Primer: Inorganic Zn- Silicate Intermediate: high Build Epoxy MIO Top Coat: 2 pack Aliphatic PUR 1 2 1 50 160 (2x80) 50 C 3 Non-immersion Medium Corrosion ( Temperature up to 400oC Sa2.5 Medium Durability Aluminum Coating 2 250 Long Duration Primer: Inorganic Zn- Silicate Top Coat : Silicon Based Coating 1 2 50 200 C 3 Non-immersion Medium Corrosion ( Temperature up to 600oC Sa 2.5 Medium Durability Primer - Silicon Based Top Coat : Polysiloxane 1 2 50 250

Immersion Service Tanks for fuel, oil, crude, chemicals and process water Sa 2.5 Solvent Less Epoxies 1 500 Immersion Service Sewage lines, water treatment facilities Sa 2.5 Glassflake Epoxies

• r

Combination of Glassflake and Reinforced epoxies 1 or 2 1000 or more Immersion Service Splash Zone in Sea Water Underwater Sa2.5 HA 2 Polyester Glassflake Water Repellent Epoxies 1 2 1000 2x400 Immersion Service Water Jetties Sea Water Sa 2.5 Glassflake Epoxy Or Novolac Epoxy 1 or 2 1500-2000 Immersion Service Freshwater Treatment facilities, locks and gates Sa 2.5 Solvent less Epoxies 1 1000 Underground Structures Gas Pipelines Water Pipelines Sa 2.5 External Oil & Gas 3 layer PE ( FBE Primer, Adhesive and PE) Water Pipelines Coal tar or Tar Epoxy, tar-urethane Liquid Epoxy, Elastomeric PU 3 1 2000 – 3000 3000-5000 700-1000

Quality Control for Protective Coatings Projects

A.S.Khanna Corrosion Science & Engineering IIT Bombay

Definition

• QC gathers and documents the information that verifies that the

work performed meets the minimum standards as required by specifications.

• Quality assurance (QA) on the otherhand is to protect the against

failures of quality control. It is process to verify that quality work was performed actually as claimed on the basis of QC.

• The quality programme assures and controls the QA and QC as per

industry standards.

• The QC manager is a qualified person, appointed by top

management to assure the quality of coating, which is evaluated on annual basis and recommendations of the corrective measures if any.

• QA and QC inspector is the qualified person appointed by QC

manager to perform individual inspections and verify the work being performed as per specifications, can introduce corrective measures

• r stop work, if not going as per specifications

Standards & Guidelines

• 1. SSPC-QP1 Standard Procedure for evaluating

painting contractor( field application to complex industrial structures)

• 2. SSPC-QP3 Standard Procedure for evaluating

Shop Painting Applicators.

• 3. SSPC-QP5 Standard Procedure for evaluating

qualifications of coating and lining inspection companies .

Pre-Job Review

• 1. Contract & Specification review.
• 2. QC and inspector Requirements
• 3. Inspection Plan
• 4. Document control
• 5. Pre-job conference

QC and inspector Requirements

• 1. Formalised training & Certification of the inspector.
• 2. Experience in the type of structure to be inspected.
• 3. Availability of inspection equipments to the

inspector.

• 4. Records of all inspection equipment used by

inspector.

• 5. Standards & Procedures to show conformance with

The specifications be available with the inspector.

• 6. Approved copies of materials supplier technical data

sheets, application instructions and material safety.

Inspection Plan

• Prior to the start of work,
• Immediately following the surface preparation.
• Immediately prior to the coating & lining

application.

• Following the application of each coat
• Following the curing of coating or lining.
• Final inspection and sign off

Daily Inspection Activities

• 1. Revision Log
• 2. Technical resource availability
• 3. Calibration verification
• 4. Daily work log
• 5. Daily inspection report
• 6. Corrective Actions
• 7. Photographic Records
• 8. Management review

Technical resource availability

• SSPC Painting Manual Vol. 2, systems &

specifications

• SSPC PA2, Measurement of DFT
• SSPC visual standards
• ASTM protective coating inspection standards for

field and shop applications.

• Updated material supplier technical data sheets.
• Standard procedures SSPC, NACE, ASTM, API, ISO

Calibration verification

• Equipment type & serial number
• Required frequency & calibration method.
• Record of calibration data.
• Signature and date of person performing

calibration verifications.

Daily inspection report

• Weather and site condition.
• Pre-surface condition & cleanliness
• Surface Preparation monitoring.
• Post surface preparation cleanliness and profile.
• Coating material preparation & application
• Physical film properties, DFT measurement
• Verification of corrective actions prior to final

approval.

• Record of equipments used for measurement