for the Coating

25.06.2007

“Practical Aspects of Corrosion Protection

Dimitrios Sariklis Germanischer Lloyd

25.06.2007Corrosion Protection PEPEN June 2007 No. 2

Type of Coatings

• 1 or 2 Component (drying / curing)• Type of binder (epoxy, polyurethane)• Type/Quantity of solvents (solventless, solventfree,water)• Purpose of the coating (primer, filler, finish)

(antifouling, anti-skid flooring)

Primer

Corrosion protection

Antifouling

Coatings


Type of Coatings

• 1 or 2 Component (drying / curing)• Type of binder (epoxy, polyurethane)• Type/Quantity of solvents (solventless, solventfree,water)• Purpose of the coating (primer, filler, finish)

(antifouling, anti-skid flooring)

Primer

Corrosion protection

Antifouling

Coatings


Type of Coatings

Coatings

2-comp. 1-comp

with active pigments without

EP-Zn

EP-Zn-phos.

Zn-silicate

PUR-Zn

pure EpoxyEpoxy-tar/-CH

Acryl/Isocyanat

Polyurethane

Polysiloxane

with active pigmentswithout

EP-ester-Zn

Alkyd Zn-phos.

chlorinatedrubber

PVC

Alkyd

Vinyl

Acrylic

BitumenCoaltar

in most EU countries:no red leadno tarno asbestosno chlorine

Coatings


(Shop)-Primer Filler Finish

wetting the substrate corrosion protection Gloss

adhesion to substrate barrier against medium

stability of colour

weldable (Shoppr.) barrier against diffusion

UV-Stability

give adhesion to the next coating abrasive resistant dirt repelling

compatible to many coatings

give thicknesscolour saturation

active corrosion protection

level the structure (edges, welding seems)

smooth surface

Properties of Different LayersCoatings


High-Solid and Solvent-free Products for BWT

Volatile components

(solvents, evaporating agents)

Solid volume (%) f.i. 70%

30 %

70 %Non volatile components

(binder, filler, pigments)

wft (mic) * = dft (mic)70 %100

dft (mic) * = wft (mic)sol.vol (%)100

150 * = 215 (mic)70(%)100

Coatings


High-Solid and Solvent-free Products for BWT

• what is neccessary?

1. Low viscosity of binder, hardener, extender

2. Agent, which improvethe flowing

3. Higher temperature of the paint for spraying

4. Efficient sprayingequipment

5. Short hoses6. Good ventilation

• f.i. Epoxy paint

30 %

70 %

<5 %

<95 %

<20%

>80 %

high solidnormal „solventfree“

Coatings


Chemical resistant coatings for tanks

• Resistance against- organic chemicals- crude oil- solvents- anorganic acids- alcalics

Coatings


Chemical resistant coatings for tanks(Phenolic Epoxy coating)

• Surface Preparation:

--- shot blasting to Sa 3 ---needs a „coarse“ profile--- no steel defects--- no pores in welding seams--- no sputters--- round edges--- welding seams smoothened

• Application: --- avoid overspray--- avoid high thickness--- proper curing/ good tempersature

• Coating

--- 2-comp. organic coating with a high crosslinking and an excellentresistance against

... Organic chemicals

... Mechanical stress

--- 3 coatings with each layer of 100 mic

--- total thickness 300 mic--- Needs temperature for curing--- If dft is too hihg : risk of mud cracking--- Good propereties, when free of pores--- less problems with repair

Coatings


Coatings for under water hullCoatings

• automatical grit blasting of the steel plates• zinc silicate shop primer (12 mic)• coating of the sections without the sectional

welding seams• surface preparation after assembling:

- derusting of the weldings and burnings bygrit blasting to Sa 2 1/2

• - cleaning the intact areas by sweeping- roughnening of the overlapping area

•application of a stripe coat•application of the corrosion protection


Coatings for under water hullCoatings

• Typical coating system for new-building

Antifouling

SealerCorrosionProtectionShoprimer12-15 mic

300-400 mic

50-100 mic

300-450 mic


Coatings for under water hullAntifouling Systems

TBT-free Antifouling

Biocides containing paints coatings free of biocides

Hard AF SPC-AFablative AF

Anti-adhesion coatings

Silicone Teflon seal-skin fish-skin

Coatings


Coatings for maintenance

Maintenance Requirements• IACS • PSC• Oil majors / charterers• Owners

Coatings


Maintenance Requirements

- IACS

Coating condition

Surveys (internal inspection)

Good S I S I S I S

Fair or Poor S A A I A S A A I A S A A I A S

Years 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Coatings


Maintenance Requirements

• PSC : • inspection if class records mention specific problem, leakage or

accusation

• Oil majors / charterers: • CAP category (CAP1 - CAP2)

• Owners: • To avoid annual surveys, acceptance by Oil majors / charterers,

reduce steel renewal

Coatings


Surface tolerant products:

• High solid modified epoxy• Tolerant to surface preparation standards• Tolerant to weather conditions• Easy to apply• Hard coats• Self priming and coating

Coatings


Ballast Water Tanks

• Hard coat

• Light colour

• Resistant to catholic protection

Coatings


Ballast Water TanksPaint systems widely used for ballast tanks

Paint System CharacteristicsPure or Modified Epoxy Two components

Light colour

Solvent Less Epoxy Two components Light colour

Solvent Free Epoxy (100% volume solids)

Two components Light colour

Epoxy Mastic and Surface Tolerant Two components Light colour

Coatings


Ballast Water Tanks

Recommended coating specification for BWT

Areas evaluated as: Coating system Dry film thickness

GOOD Hard coating 1 stripe coat1 x 100-125 microns

FAIR Hard Coating 2 stripe coats2 x 150 microns

POOR Hard Coating 3 stripe coats1x 150 + 2 x 100 microns

Coatings


Cargo Holds

Depending on the size of the vessel and the cargo:• Surface Tolerant / epoxy mastic/modified epoxy• Abrasion Resistant Epoxy• Reinforced Epoxy• Solvent Free Epoxy

Coatings


Cargo Holds

Charterers inspect the condition of cargo holds before loading.Special attention to steel structure and coating condition with emphasis to under deck and between hatches areas.

Coatings


Cargo Holds

Recommended coating specification for Cargo Holds

• Modified Epoxy: 2 x 125 microns + 1 stripe coat• Abrasion Resistant: 1 x 50-100 Epoxy Primer

1 x 200-500 Coating• Reinforced Epoxy: 1 x 50-100 Epoxy Primer

1 x 200-500 Coating

Coatings


Hull

Recommended epoxy coating specification for hull during major refurbishment:

1. Underwater areaA. Surface tolerant: 2 x 125 primer & coating

1 x 75 Tiecoat (if required)B. Abrasion resistant: 1 x 75 Primer

1 x 200-250 Abrasion resistant1 x 75 Tiecoat (if required)

Coatings


Hull

2. Topside area:A. Surface tolerant primer & coating 2 x 125B. As above plus 1 x 50 Polyurethane finish coatC. As A plus 1 X 50 Acrylic finish coat.

Coatings


Hull

Hull: During sailing and loading / discharging period very limited maintenance due to port restrictions. Main focus in maintenance of main deck area, piping, hatches etc.Recommended coating systems for main deck as Topside area.

Coatings


Methods and Influence of Surface Preparation

General AspectsSurface Preparation of New Buildings

Ballast Water TanksChemical TanksHull

Surface Preparation in MaintenanceBallast Water TanksCargo Holds/TanksHull


CategoryCategory of of CorrosivenessCorrosiveness

defineddefined inin

(EN ISO 12944(EN ISO 12944--2)2)

C2, C5C2, C5--I, Im3I, Im3

General General CoatingCoatingSystemSystem

defineddefined inin

(EN ISO 12944(EN ISO 12944--5)5)

Commercial Commercial ProductProduct

definesdefines

Surface treatmentSurface treatment

General Aspects:“The Coating System Defines the Surface Preparation”

Surface Preparation


“The Coating System Defines the Surface Preparation”

Surface Preparation


Surface Preparation

chemical methods Mechanical methods thermal methods

Pickling (Be) Flame cleaning

inductiveCleaning

(St, PSt; PMa)

Blast cleaning

grit blasting Water jetting

grit+HP-water jetting

Hand-power tools

Fl n.n.

(Sa, PSa) (Dw)

n.n.

Overview of MethodsSurface Preparation


Sa 2 ½ PSa 2 ½

Surface Preparation

Grit Blasting


total area St 3 partial area PMa (St 2)

Surface Preparation

Power Tool Cleaning


“The performance of protective coatings of paint … applied to steel is significantly affected by the state of the steel surface immediately prior to painting. The principle factors that are known to influence this performance are:

1. the presence of rust and mill scale;2. the presence of surface contaminants, including

salts, oils and greases3. the surface profile.”

ISO 8502: 1995

Surface Preparation


Properties of the Surface

VisibleVisibleContaminationContamination

RustRust

FlashrustFlashrust

DustDust

Old Old coatingscoatings

MillMill scalescale

Steel Steel defectsdefects

ForeignForeign particlesparticles

Non visibleNon visibleContaminationContamination

Oil and greaseOil and grease

SaltsSalts(Chlorides, (Chlorides, SulfatesSulfates

etc.)etc.)

Features of Features of ProfileProfile

RoughnessRoughness

defined in

ISO 8501ISO 8502ISO 8503ISO 8504

Surface Preparation


Measured by

• Electrical conductivity µS/cm

• Concentration by volume ppm = µg/cm³= mg/l

• Concentration of unit per area µg/cm² = 10 mg/m²

Invisible contaminantsSalt contamination

Surface Preparation


Sources of Salt ContaminationAtmosphere Water Abrasives Substrate

Sea sideIn the air of Baltic

Sea4 mg/l salt )

chemical and mineral industries

Hydro jettingreverse osmosis 20 µS/cm

rain water 30-60 µS/cm

fresh water 450-650 µS/cm

water of Elbe 150 µS/cm

Brackish water 9.000 µS/cm

Sea water 42.000 µS/cm

acceptable conductivityfor under water areas:

US Navy: 30 µS/cm

Hempel: 53 µS/cm

Sand

natural minerals

contaminated gritfrom circular flowacceptable content:

less 0,5%

Old coatingscontaminated from

use

Below rust

dust from blastingprocedure

sulfate-nests cause flash rust

Surface Preparation


Roughness

Sa 2 ½ shot-blasting

Surface Preparation


Surface Preparation in Maintenance

• During dry-docking and major refurbishment

• During sailing (maintenance on board)

Surface Preparation



Ballast Water TanksCargo Holds / TanksHull

Surface Preparation


Surface Preparation in Maintenanceof Ballast Water Tanks

Surface Preparation



IACSGuidelines for Coating Maintenance and Repairs

Surface Preparation



IACS clarification for “GOOD”, “FAIR” and “POOR” coating conditions

Surface Preparation



Good coating condition

Surface Preparation



Good Coating condition Transition to fair condition

Surface Preparation



Fair condition

Surface Preparation



Transition fair to poor. Fair condition

Surface Preparation



Transition fair to poor condition – poor condition

Surface Preparation



Poor Condition

Surface Preparation


Surface Preparation in MaintenanceBallast Water Tanks / Cargo Holds / Cargo Tanks / HullMajor Considerations:

Safety Salt contaminationRust Scale Pitting corrosionTemperature VentilationCondensation DehumidificationCompatibility of coating systems Design / Surface area

Surface Preparation



• Pump out all mud / Cargo residues • All hot work to be completed • Erection of staging• De-scaling • HP Fresh water washing• Drying• Surface preparation• Anode protection• Compatibility of coating systems• Coating

Surface Preparation

Maintenance and Repair Process



Recommended pre-treatment Ballast Tanks Areas considered as: Pre-treatment:

•Removal of all mud, oil, grease etc•HP Fresh water washing•Drying

GOOD •Power tool cleaning to St 2-3 or equivalent

FAIR •Damaged areas to be grit blasted to Sa 2 or equivalent

POOR •All areas under consideration to be grit blasted to Sa 2 or equivalent

Surface Preparation



Recommended Surface PreparationCargo Holds / Cargo Tanks / Hull

• Grit blasting to Sa 2• Grit blasting to Sa 1 / sweeping• HPFWJ for repairs in deck mainly during voyage

Surface Preparation


Overview

Corrosion Coating defect

Coating Failures


Coating Failures

• Final result by visual inspection:• Pores, pin holes, craters,

inclusion of foreign substances(grit, dust etc.)

• Sagging, smooth flowing, porous coating

• Holidays, overspray, orange peel

• Gloss, colour, covering

• Adhesion (destroying method) can be testedwhen coating completely cured only

• Curing/ drying, sweating.

Coating Failures


Failure of different Layers

Unsuitable primer- no adhesion to the substrate

Bad quality of finish

Loss of gloss within short time

Coating Failures

No diffusion resistance because of air bubbles


Failure in applicationSpraying

• Some typical defects:

Spraying shadowsand porous coatings

Coating Failures


Spraying


Spraying shadowsand porous coatings

Porod coating

No coating

Coating Failures


Failure in steel constructionSteel Defects


Laminates

Porous welding seam, missing stripe coat

Coating Failures


Kind of Failure Frequency %-part Reason for Failure

Delamination Bad adhesion 8 25 Solvent retention, humidity, oil, grease

Blistering 10 31 Contamination of primer surface, salts, defect of cathodic protection

Cracking 2 6 Unsuitable coating system, shrinkage of high dft, Antifouling

Corrosion at special weak points

12 38 Welding seams, burned areas, poor dft, porous coatings, pin holes

Total 32 100 (26 analysed cases, multiple nominations possible)

Frequency of typical coating failures in submerged areas

Coating Failures


Coating system:

3 coatings of ice resistant epoxyd each 175 µm = 525 µm1 Sealer-coating 75 µm2 coating of biocides each 100 µm = 200 µmtotal dry film thickness (dft) 800 µm

Solvent retention

Coating Failures


Coating FailuresOsmotic Blistering


1. Cathodicpolarisation

2. Na-Ions migrationthrough the coating

3. Alcalic situationin the blister

4. Osmotic pressure and growing

Anode

Coating FailuresTypical Appearance of Osmotic Blisters


Coating failures: CrackingBreakdown where the cracks can penetrate at least one layer of the coating that can lead to a complete failure.Main cause:

1. Excessive DFT of paint2. Plastic structural deformation exceeding the elongation properties of paint film and3. Localised fatigue stress due to improper design.

Coating Failures


Coating failure: FlakingLoss of adhesion, lifting of the paint from the underlying surface in form of flakes or scales.Main cause: 1. Improper surface preparation

2. Incompatible paints3. Contamination between layers4. Excessive curing time between layers

Coating Failures


Coating failure: Sags and Runs

Sags and runs: Paint running or hanging like curtains on vertical surfaceMain cause:

1. Too thick wet paint2. Too much thinner 3. Spray gun very close to surface

Coating Failures


OutlookIMO Coating Performance Standard BWT

• Application to ballast tanks on all types of ships• Intention is a minimum useful life of the coating of 15 years• Coating Requirements (Primary/Secondary Surface Preparation, Coating

Selection, Coating pre-qualification, etc.)• Verification and Inspection Requirements• Implementation of a „Coating Technical File (CTF)“ sort of „Logbook“ for the

Coating• specification of the applied coating system• record of shipyard’s and ship owner’s coating work• criteria for coating selection, job specifications, inspection, maintenance and repair shall be

documented• CTF shall be kept on board and maintained throughout the life of the ship

Rules and Standards


Coating requirements

• Selection of the coating system• Coating type• Coating pre-qualification test• Job specification• NDFT (320 μm – 90/10 rule)

Rules and Standards


Amendments to SOLAS Regulation II-1/3.2• Presently:

• Regulation 3-2 „Corrosion prevention of seawater ballast tanks“• Applicable to oil tankers and bulk carriers constructed on or after

July 1st, 1998• Amendment:

• Regulation 3-2 „ Corrosion prevention of seawater ballast tanks in all types of ships and double-side skin spaces of bulk carriers“

• Compliance with the IMO Resolution MSC.215 (82)

Rules and Standards


Primary Surface Preparation

• Grit Blasting to Sa 2 ½• Steel profile 30-75 μm• Max. relative humidity 85%• Steel temp. more than 30 above dew point• Water soluble salt limit equivalent to NaCl 50mg/m2

• Compatibility of zinc silicate shop primer.

Rules and Standards


Secondary Surface Preparation (1)Rules and Standards

• Steel condition to ensure even distribution of coating at the required NDFT

• Removing of all sharp edges (radius 2 mm or 3 pass grinding).

• Grit blasting to Sa 2 ½ on damaged shop primer• If shop primer has not passed pre qualification tests

then at least 70% of intact shop primer to be grit blasted to Sa 2.0


Secondary Surface Preparation (2)Rules and Standards

• Surface treatment after erection• Profile 30-75 μm • Dust• Water soluble salts limit after blasting/grinding 50

mg/m2• No oil contamination


Miscellaneous

• Ventilation (drying – curing period)• Environmental conditions (rel. humidity / dew point)• Testing of coatings (no destructive tests – measure DFT

of each coat and after completion of final coat)• Repair (to be marked, effected, reported)

Rules and Standards


Implementation DatesPSPC/SOLAS Amendment: Adoption by IMO at MSC82 in December 2006

All types of shipsSize ≥ 500 GTContracted on/after 1 July 2008 orIn the absence of a contract Keel laying on/after 1 Jan. 2009 orDelivery on/after 1 July 2012.

Tanker and Bulk Carriers

Contracted on/after 8 Dec. 2006 (with adoption by IMO)

IMO CSR

WBT PSPC

19 Months

Dec. 2006 – IACS adopted a Procedural Requirement PR 34

Implementation


Implementation procedure

• Accepted on 1 January 2008 if no objections of certain conditions have occurred

• If accepted then enter into force on 1 July 2008 under consideration of the application dates

Rules and Standards


Further Actions

• Development of a similar standard for void spaces currently in process

• Development of a standard for maintenance

Rules and Standards


Further International Guidelines from IACS

• Definition of coating conditions in „GOOD“, „FAIR“ und „POOR“ acc. to IACS Recommendation 87

• Assisting surveyors, owners, yards, etc.

• Intended for survey, assessment and repair of coatings in ballast tanks

• www.iacs.org.uk Guidelines and Recommendations

Rules and Standards


Thank you for coming!

Think of maintenance!!!

Closing


Germanischer Lloyd Academy

Vorsetzen 35

D - 20459 Hamburg

Germany

Phone: +49 40 36 149 195

Fax: +49 40 36 149 7429

[email protected]

http://www.gl-group.com/glacademy

Contact


Thank you for your attention!

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