csioct192010solublesaltnon-vendorspecificshow_2

How to Avoid Premature How to Avoid Premature Coating FailuresCoating Failures

Presenter: Regis DoucetteChlor*Rid Intnl., Inc.

(201) [email protected]

Proper Removal of Soluble Salts After Detecting Their Presence

CSI Webinar 10/19/10

AwarenessRecognitionElimination

Objective: Reduce liability of premature coating failure from corrosion with better knowledge and field-tested specification detailsGoal: Achieve full life cycle coating performance

Coating project costs: 80/20 rule applies 80% Surface Preparation 20% Coating

Why salts are a big issue?Why salts are a big issue?

Lead based coatings are banned.– Lead formed insoluble salts.

Visual standards are insufficient.– Salts are nonvisible.

Specifications may not adequately address nonvisible contaminants.– Residual salts are a leading cause of premature coating failure.

Testing and removal is always much less than the cost of premature failure.

Salts are a controllable variable!

Uhlig and Revie’sUhlig and Revie’sCorrosion & Corrosion ControlCorrosion & Corrosion Control::

““The most important single factorThe most important single factorinfluencing the life of a paint isinfluencing the life of a paint is

the proper preparation of the metal the proper preparation of the metal surface”surface”

H. Mitschke’s award winning 2001 JPCL article: A 1µg/cm2 increase in chlorides has the potential to reduce coating life by 50%.

Reality CheckReality Check

“Prior to 1995, it is estimated that at least 3 out of 4 contractors suffered major failures during projects or shortly thereafter. Most coatings did not survive more than 5 to 7 years. Now with changes, including (soluble salt remover), we have an approximately 70 to 90% reduction in lifecycle costs, have reduced premature coating failures and increased service life.”

Non vendor specific edit

What are Soluble Salts?What are Soluble Salts?

Ionic contaminants Water soluble inorganic compounds Primarily chlorides, sulfates, and

nitrates Non-visible contaminants Can bond electrochemically to the metal substrate

SourcesSources Marine environments (sea water-chlorides) Abrasives (chlorides/sulfates) De-icing salts (chlorides) Environmental fallout & acid rain

(sulfates/nitrates):– Stack gases– Auto/vehicle emissions

Chemical processes/plants & power plants (many combinations of salts)

Water and sewage treatment facilities Lightning

Sulfuric Acid Reigns Supreme

http://www.turi.org/library/turi_publications/massachusetts_chemical_fact_sheets

http://www.turi.org/library/turi_publications/massachusetts_chemical_fact_sheets

Sulfates

Chlorides

Nit

rate

s

Non-visibleNon-visible

Visually clean substrates are not adequate

Soluble salts require testing to be detected

Which salt is the problem? - Primarily dependent on service environment

•Pinky fingerprint approximates 1 square centimeter

•M&M candy sliced into one million pieces --single slice = 1 microgram

•Salt packet from McDonalds for fries --disolved in water

--then spread over 1,000 sq ft would deposit 1 microgram per square centimeter

µg/cm2

Microgram per square centimeter

Relative Size ChartRelative Size Chart40 mil

Perspective -- SizingPerspective -- Sizing

Hair

Beach Sand

Detrimental Effects of SaltsDetrimental Effects of Salts

Interferes with adhesion Accelerates corrosion Causes blistering of coatings

Corrosion CellCorrosion Cell

A corrosion cell consists of 4 components

An anode ( “-” provided by steel itself) A cathode ( “+” provided by steel itself) A metallic pathway (provided by steel itself) An electrolyte (salt + moisture = electrolyte)

Cathode

Anode

Metallic pathway

Electrolyte

Coating failure

Corrosion products

Electrolyte—the Electrolyte—the ONE and ONLYONE and ONLY variable we variable we can control is…can control is…

Salts are hygroscopic = Draw moisture

All liquid applied coatings are permeable and salts will draw moisture through the coating film, thereby providing the electrolyte needed for corrosion activity

Some coatings are less permeable than others

Osmotic BlistersOsmotic Blisters

The same hygroscopic action which causes corrosion also causes osmotic blistering

The hygroscopic action of salts builds up pressure within a blister which can exceed the bond strength of the coating

A. B.

A = Fingerprint effect B = Random test sample location would yield imperfect results

Salt Corrosion CycleSalt Corrosion Cycle

Iron +Salt + Moisture = RUST + Acid

Fe + 2H+ → Fe+2 + H2↑

Fe+2 + O2 +4H+ → Fe+3 + 2H2O

Fe+3 + 3Cl- → FeCl3

2FeCl3 + 3H2O → Fe2O3 + 6HCl

Without remediation, repeat reaction cycle

Detecting Soluble SaltsDetecting Soluble Salts

Lab analysis

– Time consuming and costly. Field testing

– Conductivity

– Ion specific

Testing for SaltsTesting for Salts

Two parts: Extractions Analysis

Detecting Soluble SaltsDetecting Soluble Salts Extraction methods

• Swabbing (DI water) [25 – 35%]

• Patch Cell (DI water) [45 – 60%]

• Wet filter paper (DI water) [??]

• Magnetic cell (DI water) [45 – 60%]

• Sleeve method (proprietary acid solution) [80%]

• Boiling (lab; destructive field sample) [90 – 95%] Quantitative analysis(Sources: SSPC TU4; Third party laboratories)

Analysis methods

Two distinct methods: Conductivity – measures all conductive constituents. Ion specific – measures the specific ion of concern; chloride, sulfate, or nitrate.

Conductivity Method

Measures everything conductive in the sample. Many species are not detrimental to the coating film nor induce premature coating failure. Measures all minerals. Conversion to chloride level is an estimate.

Assumes a lab correlation based on 100% chlorides. Conductivity and reactivity are different.

ABCDEFGHIJK--LMNOPQRS

Conductivity vs Chloride Ion Specific19 panel tests with derived index for analysis

Plotted test points sorted by ascending values of Chloride Ion Specific results.

Sorted by ascending values of Conductivity results.

Ion specific method:Ion specific method:

Measures the specific problematic ion. Can measure different ions – chlorides, sulfates, and nitrates. Reagent liquid chemicals can measure chlorides, but usually result in a range ( > to < ).

Ion specific method Ion specific method limitations:limitations:

Quantab strip: Lot specific factor for calculation. Does not read below 30 ppm;

• 7.5 µg/cm2 equivalent with Bresle and 3 ml DI. Reagent liquid chemicals can measure chlorides, but usually result in a range ( > to < ).

Chloride Analysis by Ion Chloride Analysis by Ion Detection TubesDetection Tubes

Sealed ampoule, break both ends and immerse in extract solution

Cl- read from calibrated tube in PPM and micrograms per square centimeter

ISO 8502-5

Analysis of SulfateAnalysis of Sulfate

Electronic turbidity method– Add barium chloride to extract solution to form

BaSO4

– Measure absorbency/transmittance New Field Test Kit ISO 8502-11

– Maryland Bridge– I-95 Delaware– Casciano Bridge near Newark A/P

Analysis for NitratesAnalysis for Nitrates

Dip pillow end of nitrate strip into extracted solution for 2 seconds

Wait 1 minute and compare color on pillow to color on comparator card

– NASA Gantry

– St. Lawrence Seaway

Criteria for Chlorides:Criteria for Chlorides:

Units = µg/cm2

* Equivalents

SourceSource Immersion Immersion AtmosphericAtmospheric

SuppliersSuppliers 2 - 5 2 - 5 5 - 155 - 15

NAVSEANAVSEA 33 55

NAVFACNAVFAC NDND NDND

IMOIMO 3*3*

DNVDNV 22 22

Risk Levels for Soluble Salts:Risk Levels for Soluble Salts:

Soluble saltSoluble salt ChlorideChloride NitrateNitrate SulfateSulfate

UnitUnit µg/cmµg/cm22 µg/cmµg/cm22 µg/cmµg/cm22

Low RiskLow Risk 0 to 30 to 3 0 to 50 to 5 0 to 100 to 10

Medium RiskMedium Risk 3 to 83 to 8 5 to 105 to 10 10 to 2010 to 20

High RiskHigh Risk >8>8 >10>10 >20>20

Cumulative RiskCumulative Risk Threshholds for each, but risk additive &

not independent nor mutually exclusive How much weight should go on thin ice?

Chlorides

Sulfates

Nitrates

Units for Soluble SaltsUnits for Soluble Salts

Surface Concentration:– Micrograms per square centimeter– Abbreviated (µg/cm2)

Solution Concentration:– PPM (parts per million)– Convert to µg/cm2 based on volume and

area

Note: 10 mg/m2 = 1 µg/cm2

StandardsStandards

SSPC Guide 15– extraction procedures– analysis procedure– units, conversions

ISO – chloride ion, sulfate ion– conductivity– extraction

Removal

The electrochemical attachment of salts to

the substrate (adsorption) are greater than

the forces applied to remove them.

Bonding strength

Why are salts left behind if theyare water soluble?

Surface Preparation MethodsSurface Preparation Methods Ultra High Pressure washing

- Profile impact- Salt mitigation

Abrasive blasting & Pressure wash (3000 psi min) cycles with water.- Multiple passes.

- Bonded salts.- Time and cost.

Wet abrasive blasting - Micronic particles. - Rinsing required. Abrasive blast followed a soluble salt REMOVER

wash. - Cost effective.

Coatings Economics

Goal: Achieve lowest cost/ft2/yr for the expect coating lifeTotal Surface Area:Total Surface Area: 90,000 ft90,000 ft22 Service: Tank LiningService: Tank Lining

Insufficient Surface Prep:Insufficient Surface Prep: $500,000$500,000 5 yr coating cycle5 yr coating cycle

Proper Surface Prep:Proper Surface Prep: $515,000$515,000 15 yr coating cycle15 yr coating cycle

Cost/ftCost/ft22/yr (today’s $):/yr (today’s $): Cost /yr over 15 yrsCost /yr over 15 yrs

Insufficient Surface Prep:Insufficient Surface Prep: $1.11/ft$1.11/ft22/yr/yr

Proper Surface Prep:Proper Surface Prep: $0.38/ft$0.38/ft22/yr/yr

Based on actual experience by NAVFAC since instituting revised specifications in 1995.

Coating Life Cycle Comparisons

0

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Year

Init

ial Pro

ject C

ost ($

K)

Proper Surface Prep Insufficient Surface Prep

SummarySummary

Awareness:– Salts may be present

Recognition:– Incorporate testing in specifications– Testing to quantify levels present

Elimination:– Traditional surface prep methods may not remove

salts adequately.– Cost effective use of acidic soluble salt remover– Test to verify prior to coating.

Uhlig and Revie’sUhlig and Revie’sCorrosion & Corrosion Corrosion & Corrosion

ControlControl::

“…A poor paint system on a “…A poor paint system on a properly prepared metal surface properly prepared metal surface

usually outperforms a better paint usually outperforms a better paint system on a poorly prepared system on a poorly prepared

surface”surface”

Strive for ProductsStrive for Products

Proven Efficient Improves Adhesion Assists in removal of surface oils Cost effective Safe Easy to use Environmentally friendly

Ten Best Management Practices

• Industry Associations• Quality Control• In Service/Field

Surface Preparation of Soluble Salt Surface Preparation of Soluble Salt ContaminatedContaminated

Steel Substrates Prior to CoatingSteel Substrates Prior to CoatingNACE International Publication 6G186NACE International Publication 6G186

The purpose of this technical committee report is to increase the industry awareness of the following:

• The effects of various nonvisible soluble salt contaminants on a coating’s performance;

• An approach to risk assessment regarding the costs of soluble salt removal versus the risk of future

coating failure;

• Identification of the indicators of salt contamination; and

• Various methods of salt contamination removal.

Section Headers as presented on Page 1 of this report, verbatim



Appendix B

Preparing a Specification

B1 Specification requirements regarding salt testing are usually driven by the specification writer’s knowledge of salt test kits….

B2 Some of the basic components of a specification associated with nonvisible soluble salts include, ….(next slide)

B.3 Numerous sampling methods are described in SSPC-Guide 15. ….

B.4 Appendix C is an example of a portion of a written specification for a lining that incorporates these components.

Appendix B has been provided courtesy of the Salt River Project (SRP)…Tempe, AZ



(a) Identify a field test kit or method for extraction and the method of analysis for each type of salt contaminant;

(b) Determine at what point in the project activity testing occurs, taking into consideration surface preparation methods and procedures;

(c) Choose the number of tests to be performed or a method for identifying the number and frequency of testing;

(d) Give guidance on or select test locations;

(e) State what level of soluble salt contamination is acceptable (see the product data sheet for the coating, or consult the coating manufacturer); and

(f) Indicate remediation method(s) and subsequent retesting for previously noncompliant surfaces.



•Effect of Salt Contamination on Coating Performance•Risk Assessment•Salt Contamination Sources•Water-Soluble Salt Contaminants (Chlorides, Nitrates, and Sulfates)•Recognition and Identification of Salt Contaminants•Field Tests to Detect the Presence of Salts•Salt Removal Methods•Project-Specific Sampling Protocols and Acceptance Criteria

Section Headers as presented on Page 1 of this report, verbatim



•References•Appendixes:

– A. Area-Based Sampling Protocol and Testing

– B. Preparing a Specification– C. Example Lining Specification

Section Headers as presented on Page 1 of this report, verbatim (continued)


Steel Substrates Prior to CoatingSteel Substrates Prior to CoatingNACE International Publication NACE International Publication

6G1866G186www.nace.org

Store

Members free; non-members $31

Technical Guide #15The Society for Protective Coatings

Draft Version American Petroleum Institute

Specification

BEST PRACTICES (BMP)BEST PRACTICES (BMP)

Unified Facilities Guide Specifications

Societies

Quality Control Called in specs—Warranty ONLY

Repeated mentor advice to test for salts rather than risk fiasco

Specification


Several pages address similar to Dewpoint, RH, Temp. KEY Criteria

QC Caring

Quality Control -- Fleets & Structures proper washdown should not harm assets

Concrete and other repairs, intercoat adhesion issues

Specification


Pipelines/structures when redoing CP clean properly

In Service/Field

NAVSEA: 009-32 Standard ItemNAVSEA: 009-32 Standard Item

Chloride limit: 3 µg/cm2 immersion. FY-10: Water wash to meet the limit after abrasive blast.

– Can require multiple washes. FY-11 (Prelim): Allows the use of an approved salt

remover.– Approval via the F718 from the coating manufacturer

ONR funded research at Carderock and CTC, Johnstown support efficacy and acceptability of an established and time tested soluble salt remover.

Surface Preparation IssueSurface Preparation Issue

Industry standards are generally visual. Present coatings cannot tolerate salts. Non-visible contaminants are getting more attention. Soluble salt removal is critical to coating life cycle

performance.

Enclosed LifeboatEnclosed Lifeboat

Courtesy of US Coast Guard

Cable for aft hookCable for aft hook

PRIOR VIDEO and these next 5 slides courtesy of US Coast Guard


Case 1Case 1Type: Crude Oil Tanker DWT: 135,000

Age Of Vessel : 16 Years,

Total Steel replacement : 1,200 Metric Tonnes

Case # 1..

Renewals were carried out on various internal structures in Cargo & Ballast tanks including areas on the bottom plating


Case 1Case 1Case 1.. Cont’d..

The

Final

Product

Arrival Condition

The renewal Process on the Ship....


Type: Oil Tanker , DWT: 108,628 Age Of Vessel : 15 Years,

Total Steel renewal was : 150 T .. And steel renewal was Limited only to Ballast tank areas…

Case 2..

What happened : Case # 1 = 1200 Tonnes and Case # 2 = 150 Tonnes.

Reason : The Ship owner in Case # 2 did better Preventive Maintenance during her trading Years!!

Case 2Case 2


The B-307 was flown to Dulles in The B-307 was flown to Dulles in 2003 for delivery to 2003 for delivery to the the

SmithsonianSmithsonian

Boeing Removes Corrosion Inducing Salts from Ditched Aircraft

Repairs:Repairs:

Incorporating Salts into Incorporating Salts into a SPECIFICATIONa SPECIFICATION

THE GOOD THE BAD

and THE UGLY

WHAT IS A SPECIFICATION?WHAT IS A SPECIFICATION?

(Class response)(Class response)

A specification is the “legal A specification is the “legal written word” requiring a written word” requiring a

contractor to perform certain contractor to perform certain tasks.tasks.

The GoodThe Good

Specify- State in detail (Webster’s College Dictionary)

A specification should clearly state what is required of the contractor.

A specification should sequentially delineate each course of action.

The BadThe Bad Do not repeat statements in a specification.

State it only once. Even a slight change in verbiage will give different meanings to the intended meaning.

Do not use ambiguous statements such as “or equal”. If “or equal” is used clearly state

what is equal.

The UglyThe Ugly Do not use long sentences. Short sentences are

more easily understood.

Use concise and accurate industry language. mg/cm2 is not micrograms per square centimeter.

PPM does not convey the correct information regarding contamination on a surface.

Specification LanguageSpecification Language(answer these questions)(answer these questions)

What Where When How How many

WHAT?WHAT?

What salts need to be tested:What salts need to be tested:chlorides, sulfates and/or chlorides, sulfates and/or

nitrates nitrates

WHERE?WHERE?

Where are the tests to be taken:Where are the tests to be taken:in corroded areas, at welds, on in corroded areas, at welds, on the floor, on the ceiling, on the the floor, on the ceiling, on the

sidewalls etc. sidewalls etc.

WHEN?WHEN?

When are tests to be taken:When are tests to be taken:

before and/or after surface before and/or after surface preparation, after a storm re-preparation, after a storm re-contaminates the surface etc.contaminates the surface etc.

WHY?WHY?

Test because the specification Test because the specification requires a maximum acceptable requires a maximum acceptable

level be achieved prior to level be achieved prior to coating application coating application

HOW MANY?HOW MANY?

Test per specified frequency:Test per specified frequency:

(5 tests per 1000 sq ft. or part (5 tests per 1000 sq ft. or part thereof)thereof)

SALTS IN A SPECIFICATIONSALTS IN A SPECIFICATION1. Test before preparation (this is a baseline)

2. Wash before preparation if salts do not meet specification (prevent possible impregnation)

3. Prepare surface

4. Test after preparation (this establishes if remediation is required)

5. Remediate if necessary

6. Retest to establish if specification is met

Test Where?Test Where?

Test at locations of corrosion

Test at locations of coating failure

Test at weld seams

Exactly Where Do I Test?Exactly Where Do I Test?

On metal loss areas- 70% of total tests. Next to welds (30%) (vertical and

horizontal). If no metal loss areas are visible, select

areas representative of the surface as a whole.

Areas not washed by rainfall

When do I test?When do I test?

Prior to surface preparation (this establishes a starting base level)

After surface preparation but prior to coating (this determines if further surface cleaning is needed)

After decontamination (if salts meet the required level, coating may progress).

Between coats if coating has become contaminated.

How many tests do I take?How many tests do I take?New Construction/Complete New Construction/Complete

Removal/ReplacementRemoval/Replacement

Five (5) tests for the first 1000 square feet (1002 meters) or part thereof.

Two (2) tests per 1000 square feet for the next 3000 square feet (3002 meters) or part thereof.

One (1) test per 2000 square feet (2002 meters) on the remainder or part thereof.

Ft2 (m2) Number1,000 (100) 52,000 (200) 5+2=73,000 (300) 5+2+2=94,000 (400) 5+2+2+2=116,000 (500) 5+2+2+2+1=128,000 (800) 5+2+2+2+1+1=1310,000 (1,000) 5+2+2+2+1+1+1=1412,000 (1,200) 5+2+2+2+1+1+1+1=1514,000 (1,400) 5+2+2+2+1+1+1+1+1=1616,000 (1,600) 5+2+2+2+1+1+1+1+1+1=17

REPAIR ATMOSPHERIC– Recommended Number and Distribution of Measurements: Spot Repair for Used Surfaces

How Many Tests??? (Repair)

Ft2 (m2) Floor Measurements Ceiling Measurements Wall Measurements1,000 (100) 5 5 5

2,000 (200) 5+2=7 5+2=7 5+2=7

3,000 (300) 5+2+2=9 5+2+2=9 5+2+2=9

4,000 (400) 5+2+2+2=11 5+2+2+2=11 5+2+2+2=11

6,000 (600) 5+2+2+2+1=12 5+2+2+2+1=12 5+2+2+2+1=12

8,000 (800) 5+2+2+2+1+1=13 5+2+2+2+1+1=13 5+2+2+2+1+1=13

10,000 (1,000) 5+2+2+2+1+1+1=14 5+2+2+2+1+1+1=14 5+2+2+2+1+1+1=14

12,000 (1,200) 5+2+2+2+1+1+1+1=15 5+2+2+2+1+1+1+1=15 5+2+2+2+1+1+1+1=15

14,000 (1,400) 5+2+2+2+1+1+1+1+1=16 5+2+2+2+1+1+1+1+1=16 5+2+2+2+1+1+1+1+1=16

Tank Linings – Recommended Number and Distribution of Measurements: New and Old SurfacesThat Require Full Coating

(EXTERNAL SURFACES AND STRUCTURES)

How Many Tests??? (Tanks)

MAINTENANCE PAINTINGMAINTENANCE PAINTING

Atmospheric/Immersion

For the first five (5) spots one (1) test per one (1) spot.

Remainder of structure - one (1) test per five (5) spots.

Where, When, How Many and Where, When, How Many and Allowable LevelsAllowable Levels

ACCEPTABLE LEVELSACCEPTABLE LEVELS

Immersion at Ambient TemperatureImmersion at Ambient Temperature

Chloride Nitrate Sulfate

Low Risk 0 to 3 0 to 5 0 to 10

Med Risk 3 to 8 5 to 10 10 to 20

High Risk >8 >10 >20

Atmospheric at Ambient Atmospheric at Ambient TemperatureTemperature

Chloride Nitrate Sulfate

Low Risk 0 to 7 0 to 10 0 to 15

Med Risk 7 to 15 10 to 20 15 to 30

High Risk >15 >20 >30

Uhlig and Revie’sUhlig and Revie’sCorrosion & Corrosion Corrosion & Corrosion

ControlControl::

“…A poor paint system on a “…A poor paint system on a properly prepared metal surface properly prepared metal surface

usually outperforms a better paint usually outperforms a better paint system on a poorly prepared system on a poorly prepared

surface”surface”

1. A fast, cheap job is not good. 2. A cheap, good job is not fast.

3. A good, fast job is not cheap.

Summary of Key PointsSummary of Key Points

Soluble salts are widespread Salts cause coating failure Levels of acceptance Field methods for extraction Field methods for analysis Specification writing

csioct192010solublesaltnon-vendorspecificshow_2

Documents

removal of soluble salts

adequatesoluble salts

residual salts

coating life

combinations of salts

formed insoluble salts

soluble salts0

cost of premature failure