WELCOME ESTEEMED DELEGATES - ESI Africa

WELCOME ESTEEMED DELEGATES

It is with great appreciation that this workshop is being hosted.

This workshop will empower you to address the ‘Weakest

Link’ found on all Utility infrastructure throughout Africa. This

is a 1st of a kind event, presented by a panel who are

passionate contributors in the field of corrosion.

We are going to share this information with you.

Protect your Critical Assets - HRCSA

Africa’s largest power Utility is leading the way by implementing a specialized joint sealant technology. In collaboration with various Stakeholders, this proven and tested technology protects the “Weakest Link” against Crevice Corrosion.

Utilities depend on structural integrity and longevity of assets with the aim to minimise maintenance.

Crevice corrosion, second to vandalism, is the largest threat that Utilities face.

For new and weathered metal and concrete infrastructure, these speakers, with years of interaction with a variety of Stakeholders, who are all experts in the fields of Metallurgical Science, Industrial Coatings Technologies and Energizing Sub-Sahara-Africa, will provide you with a detailed insight into Crevice Corrosion and how to reduce Crevice Corrosion related maintenance.

“Projects provide new challenges and solutions

through successful interventions”.

Today we are sharing this information with you.

SCOPE OF TODAYS DISCUSSIONS

What is the Weakest Link

Nut & Bolt Corrosion

Protection Methods - Passive Barriers

- Active Seals

Chemistry of HRCSA

Training Requirements

SOLAR ARRAY ASSEMBLIES

USES DIFFERENT

METALS

ALUMINIUM

STAINLESS STEEL

COPPER

GALVANIZED STEEL

CHALLENGE

PHOTOVOLTAIC MODULES

Designed for an operational life span of more than 25 years

in the field.

Entire installation including the fasteners, should target a

similar life span - but

The Fasteners are corroding.

The Fixing Brackets are corroding.

CREVICE CORROSION

FASTENERS

CREVICE CORROSION

THE WEAKEST LINK

The fate of a complex steel assembly may be determined by

the vulnerability of its smallest and least considered

components.

The fasteners holding the assembly together are the areas

where corrosion starts first, where the effects of crevice

corrosion has the most serious consequences.

MOST SERIOUS THREAT TO ASSET OWNERS

WHY DO BOLTS RUST SO EASILY?

In steel bolted systems, large components are assembled and

secured, using relatively small nuts and bolts.

Assemblies are everywhere - Lattice Towers, Substations,

Water Reticulation Systems and other metal infrastructure.

In the joins, Differential Aeration Corrosion is the just one of

the causes – The Greatest Threat.

ALL STRUCTURES MOVE

Pulsation, Vibration & Thermal Fluctuation

Weight Loads, Thermal Fluctuation, Lateral

Deflection (wind)

AT THE FASTENERS WHERE JOINTS ARE CLAMPED

PIPELINES

&

MACHINERY

LATTICE

STRUCTURES

BOLT CORROSION - DIFFERENTIAL AERATION

CORROSION

CROSS-SECTION OF CORRODED NUT & BOLT

NUT & BOLT CORROSION EXPLAINED

BOLT PROTECTION AGAINST CORROSION

HOT DIP GALVANIZING OF FASTENERS FOR

PROTECTION

WHEN HOT DIP GALVANIZING, THREADS OF THE NUT

ARE OVERSIZED TO CREATE SPACE FOR THE ZINC

BY DOING SO THE TENSILE STRENGTH OF THE BOLTS

ARE WEAKEND

LOAD

DISTRIBUTION

The first two

threads hold 57%

of the load

If the first thread

fails, the rest

follow in a domino

effect

TENSILE STRESS VS. SHEAR STRESS

Failure occurs in the threads at the fastener’s weakest

point, made weaker by oversizing.

The amount of tension created in a bolt not only

depends on the strength of its body but on the shear

strength of its threads.

Thread pitch engagement needs to be close to 100%,

to develop the full ultimate strength of the bolt.

CORROSION

“Bimetallic corrosion occurs when 2 metals, with different

potentials, are in electrical contact while immersed in an

electrically conducting liquid. Because the metals have different

natural potentials in a liquid, a current will flow from the anode

(more electronegative metal) to the cathode (more

electropositive metal), which will increase the corrosion on the

anode.” Corrosion Exclusively Vol.2 Issue 2, 2016 p26.

WHAT CAUSES CORROSION?

Moisture (electrolyte – H2O)

Oxygen (O2)

MULTI Metals (fasteners, washers, flanges, welds)

Allowing - CORROSION CELL FORMATION

ATHMOSPHERIC VAPOUR

PLANTS - DEW METAL - CONDENSATE

CORROSION CELL

COMPONENTS:

WATER (H2O)

OXYGEN (O2)

ELECTRON FLOW

(Electric current)

Iron (Fe)

ANCHOR BOLTS & FOUNDATIONS

CONDENSATE RUNDOWN

ANCHOR BOLTS & FOUNDATIONS

ANCHOR BOLTS & FOUNDATIONS

HOW TO PROTECT YOUR ASSETS?

• FASTENERS

• BRACKETS

• EQUIPMENT

COMPONENTS

• MEMBER

INTERFACES

• JOINTS

• ANCHOR BOLTS &

FOUNDATIONS

PROTECTIVE COATINGS

TWO TYPES

PASSIVE

BARRIER

ACTIVE

SEAL

PASSIVE BARRIER COATINGS

PASSIVE

BARRIER

EPOXIES

POLYURETHANES

INORGANIC ZINC COATINGS

POLYSILOXANE (SILICONE)

WEAKNESS HARD & CRACK - ALL STRUCTURES MOVE.

NO CHEMICAL REACTION WITH METAL.

LEADS TO UNDERCREEPAGE.

ARE ALL INERT LAYERS OF COATINGS FORMING A PASSIVE SHELL

PASSIVE

BARRIER

ACTIVE SEAL COATINGS

HOT DIP GALVANIZING

HIGH RATIO CALCIUM

SULFONATE ALKYD

(HRCSA)

ACTIVELY REACTS WITH THE SURFACE OF THE METAL

SUBSTRATE

ACTIVE

SEAL

HOT DIP GALVANIZING

PROVIDES ACTIVE SEAL PROTECTION

Zinc Carbonate Layer (Not easily removed)

CATHODIC PROTECTION – Zinc (ANODE)

is electro-negative to carbon steel

HOW TO MITIGATE CORROSION?

Eliminate the electrolyte

or

Prevent the flow of electrical current

or

Prevent oxidation

or

Modify the environment

HRCSA DOES ALL OF THESE!

Eliminates the corrosion cell (exclude electrolyte)

&

Prevents the flow of electrical current (bad conductor)

&

Prevents oxidation (exclude oxygen)

&

Modifies the environment (raise the pH > 10)

HRCSA: PERFORMANCE BY FORMULATION

HIGH CORROSION RESISTANCE – Due to the

chemical reaction of the mild sulfonic acids in the HRCSA

with the Zinc Carbonate Layer (not easily removed) on the

metal surface of the Zinc - The pH is lifted to pH > 10.1

This modified environment actively mitigates corrosion.

HRCSA COATING: PERFORMANCE BY FORMULATION

HIGH CORROSION RESISTANCE – Due to the

chemical reaction of the mild sulfonic acids in the

HRCSA with the Zinc Carbonate Layer (not easily

removed) on the metal surface of the Zinc

The pH is lifted to pH > 10.1. This modified

environment actively mitigates corrosion.

HRCSA COATING

HIGH RESISTANCE TO UNDER-CREEP - high

affinity of the calcium sulfonate for bare metal resists the

formation of under-creeping

ADHESION BY MEANS OF

VAN-DER-WAALS FORCES –

POS & NEG ATTRACTION

HRCSA COATING

MOISTURE DISPLACEMENT - HRCSA has a higher

affinity for metal than water (hydrophobic).

The Calcite (CaCO3) platelets prevent oxygen and water from reaching the

substrate, eliminating the electrolyte needed for corrosion and oxygen

needed for oxidation

HRCSA RED PENETRANT & TOP COAT

HRCSA IS COMPATIBLE WITH CONCRETE

Uncontrolled steel chemistry explained…

PROBLEM : STEEL CHEMISTRY

HDGASA

“We are confronted with imported steel chemistry that is not always

conducive to a quality hot dip galvanized finished product

Imported steel have shown that the percentage Si and P content is not

controlled, leading to differences in hot dip galvanized steel surface

finishing’s

Uncontrolled steel chemistry has a direct influence on the quality of the

surface finish of hot dip galvanized steel”

Volume 10 Issue 3 2013 Hot Dip Galvanizing Today

KIPTS EVALUATION: DUPLEX & OVERCOAT SYSTEM

Eskom LES requested that the HIGH RATIO

CALCIUM SULFONATE ALKYD (HRCSA) be tested

before any application to steel will be considered.

ESKOM EVALUATIONNov 2013 – Nov 2015

HIGH RATIO CALCIUM SULFONATE ALKYD (HRCSA) AS

AN ACTIVE DUPLEX COATING FOR GALVANIZED STEEL

LOCATION: Koeberg Insulator Pollution Testing Station (KIPTS)

POLUTION LEVEL: CX5+ (ESKOM)

DURATION: 24 MTHS

KIPTS EVALUATION: DUPLEX- & OVERCOAT SYSTEM

TO DETERMINE PRODUCT PERFORMANCE BASED ON

VARIOUS DEGREES OF SURFACE PREPARATION

PROCEDURES DUE TO ON-SITE APPLICATION

KIPTS 2nd HIGHEST POLLUTION ZONE IN THE WORLD

KIPTS EVALUATION

SUBSTRATE PREPARATION PROCEDURES

• No Prep

• Wire brushing & dusting

• Wire brushing & water washing

• Wire brushing, water washing with salt removal

additive

SAMPLES PROVIDED

OLD & NEW GALVANIZED STEEL

SAMPLES MOUNTED

THEN COATED WITH HRCSA

NEW

GALVANIZING

SURFACE

PREP: NONE

8760 HRS

13 Nov 2013 13 Nov 2014

NO CORROSION

OR

UNDERCREEPAGE

27 Months

815 Days

19 560 Hours

NO

UNDERCREEP

OR CORROSION

AT SCRIBE

HRCSA TESTING

MILD STEEL PANEL

GRIT BLASTED TO

NEAR WHITE METAL

FULLY COATED WITH

EPOXY

THEN ½ COATED WITH

HRCSA

EACH HALF SCORED

KIPTS NOV 2013

HRCSA TESTING

NOV 2014(12 months later)

CORROSION &

UNDERCREEPAGE ON EPOXY

(PASSIVE BARRIER)

NO CORROSION OR

UNDERCREEPAGE ON HRCSA

(ACTIVE SEAL)

ENLARGED PIC

NO PROTECTION AT

SCRIBE (EPOXY)

DIRECT CONTACT

WITH ATMOSPHERE

UNDERCREEPAGE

CAUSING

DELAMINATION

AND ACCELERATED

CORROSION

3RD PARTY TESTING IN USA

U.S Army Corps of Engineers

(2 866 hrs)

PowerTech Inc. – Canada

(4 000 hrs)

Kentucky Transport Authority

(5 000 hrs)

Federal Highway Authority

(ALT – 6 840 hrs)

(Marine – 24 month) – Outdoor

Nov 2012

SA SALT FOG TEST RESULTS (ASTM B117) 1 500 HRS

Testing Laboratory: Metlab Germiston (SANAS approved)

RESULTS

The coating showed no defects after

1500h salt fog exposure.

A cross cut scribe was made through

the coating down to the metal

substrate and no under-film creep

occurred at this scribe mark during

the test period.

SA SALT FOG TEST RESULTS (ASTM B117) 1 500 HRS

Discussion of Results

The results showed excellent corrosion protection for the

period tested [1500h].

Rule of thumb - 1000h salt spray exposure test = 3 yrs

marine exposure

HIGH RATIO CALCIUM SULPHONATE ALKYD

Formulated as an overcoat & encapsulating system for

Hot dipped galvanizing

Red lead based coatings

Aluminium-Zinc coatings

Zinc-rich primers & topcoats

Direct to metal (DTM) and concrete

Passive barrier coatings (except silicone, bitumen)

ANTI-CORROSION COATING

I’m now going to hand over to

Gary Watson (President of Watson Coatings Inc.)

and

Rick Noles(Sales Director of Watson Coatings Inc.)

CALCIUM SULFONATE CHEMISTRY

WATSON COATINGS INC.

TYPES OF CALCIUM SULFONATE

• LUBRICANTS & GREASES

• FUEL ADDITIVES

• THICKNERS FOR CONVENTIONAL COATINGS

• CORROSION INHIBITORS FOR CONV. COATINGS

• AVAILABLE IN WATER-BASED AND SOLVENT-BASED

• GELLED OR OVERBASED RESINS

GELLED or OVERBASED RESINS

“WATER-BASED RESINS HAVE NOT PROVEN TO

PROVIDE THE PROTECTION OF SOLVENT-BASED”

• USED AS RESINS IN ACTIVE SEAL COATINGS

MODIFIED WITH ALKYD RESINS AND WAXES

• MODIFICATIONS INCREASE WATER RESISTANCE,

WETTING OF THE SUBSTRATE AND FIRMNESS OF THE

COATING

• MUST HAVE A HIGH RATIO OF CS TO THESE MODIFIERS

TO MAINTAIN MAXIMUM CORROSION RESISTANCE

HRCSA FORMULATION

Coatings both passive and active seals are made up of a combination

of resins, pigments, solvents and additives.

Differences in coatings and their performance are the direct results of

these components and the ratio’s that are used in their

manufacturing

In the case of HRCSA it is the calcium sulfonate resin that provides

the excellent corrosion resistance, water resistance, adhesion to bare

metal and galvanizing

HRCSA TESTED & APPLIED

Applications in the US are as old as 1998 in its current

formulation giving WCI almost 20 years experience

Multiple US DOT’s apply the HRCSA to steel bridges.

By multiple independent testing agencies, departments of

transportation, the US ARMY and actual field applications across the US and more recently by ESKOM in SOUTH AFRICA

CONTACT DETAILS

CONTACT THROUGH:

RUSTOPAK (Pty) Ltd

E-mail: info@rustopak.com or admin@rustopak.com

+27 82 789 2582 / +27 87 807 9217

URL: http://www.rustopak.com

TRAINING ON THE HRCSA

I’m going to ask Carl Havemann from Corrosion

Enterprises to explain the training that is needed to

apply the HRCSA to conform with ISO Quality

Management System.

CORROSION ENTERPRISES

PAINT APPLICATOR & SUPERVISOR TRAINING

PRESENTER - CARL HAVEMANN (CEO)

PAINT APPLICATOR TRAINING

MISSION

PROVIDE TRAINING AND UP-LIFTMENT TO THE WORKER

TRAINING TO INCLUDE THEORYAND PRACTICAL

PROVIDE CONSULTING SERVICES

COURSES

COATING APPLICATOR COURSE

SURFACE PREPARATIONBRUSH AND ROLLER APPLICATIONSPRAY PAINTING

PAINTING SUPERVISOR COURSE

Certificate issued on passing the exam

TYPICAL PAINT SUPERVISORS TOPICS

THE SPECIFICATION DOCUMENT AND ITS USE

SAFETY

USE OF PAINT DATA SHEETS

USE OF THE QUALITY CONTROL PLAN (QCP)

USING THE COLOUR STANDARD (SABS 1091)

SURFACE CLEANLINESS TO ISO 8501:1:1988

QUALITY MANAGEMENT DOCUMENTATION

• The PROJECT CONTRACT document

• SAFETY

• The PAINT SPECIFICATION document

• Paint DATA sheets (PDS & MSDS)

• The QUALITY CONTROL PLAN (QCP)

ENVIRONMENTAL CONDITIONS

AIR TEMPERATURE

STEEL SURFACE TEMPERATURE

HUMIDITY

DEW POINT

SUBSTRATE INSPECTION

• Surface Cleanliness (Sa & St)

• Water break-free on galvanizing.

• Dust and Debris(SABS 769)

• Soluble Salts(SABS SM 770)

• Dry Film Thickness(SABS SM 141)

• Adhesion Test (ASTM D3359)

PAINT FAILURES

• Pinholes• Cracking• Flaking• Blistering• Crocodiling• Wrinkling• Chalking• Fisheyeing• Blushing• Not curing or drying

SAFETY : PERSONAL PROTECTION EQUIPMENT PPE

• Overalls

• Safety Shoes

• Eye and face protection

• Hard Hat

• Gloves

• Masks (Gas/Dust)

• Ear Plugs

CONTACT DETAILS

CEO: Carl Havemann

Mobile: +27 83 400 2847

E-mail: carl@corrosionenterprises.co.za

THANKING YOU FOR YOUR INTEREST IN DRIVING INNOVATION

FORWARD!

YOU ARE WELCOME TO ASK ANY QUESTIONS YOU MAY HAVE…

Contact Details

Rustopak (Pty) Ltd

Tel: +27 82 789 2582 / +27 87 807 9217 / + 27 44 620 2478

URL: http://www.rustopak.com