introduction to coatings · anodize is a semi-transparent coating • hides small defects in the...

Introduction to Coatings

Field Performance and the Application Process

Linetec is a Registered Provider with The American

Institute of Architects Continuing Education Systems.

Credit earned on completion of this program will be

reported to CES Records for AIA members. Certificates of

Completion for non-AIA members are available on

request.

This program is registered with AIA/CES for continuing

professional education. As such, it does not include

content that may be deemed or construed to be an

approval or endorsement by the AIA of any material of

construction or any method or manner of handling, using,

distributing, or dealing in any material or product.

Learning Objectives

Participants of this course will learn how different

paint and anodize finishes rate when compared to

architectural specifications. Participants will also learn

about the application process to assure a quality

product is provided.

Length: 1 hour

Credits: 1 LU/HSW

Copyright Materials

This presentation is protected by US and International

Copyright laws. Reproduction, distribution, display and

use of the presentation without written permission of

the speaker is prohibited.

Introduction to Coatings: Field Performance and the Application Process

• The Anodizing Process

• Anodize Specifications and Performance

• The Paint Process

• Paint Specifications and Performance

• The Powder Coat Process

• Summary Comparison of all Coating Types

The Anodize Process

What is Anodizing?

Anodizing is the process of electrochemically controlling, accelerating and enhancing

oxidation of an aluminum substrate.

The anodizing process produces an oxide film that is uniform, hard and protects the

rest of the aluminum substrate from deterioration.

Electricity Chemicals

Aluminum

Aluminum Oxide Coating

Aluminum

Barrier Layer

Anodic Pore

The anodizing process thickens the natural oxide film resulting in a heavy aluminum

oxide film of controlled thickness having the hardness similar to that of a sapphire

(second hardest substance known to man).

Aluminum

Oxide

Layer

Oxide Film Structure

Anodize Performance • Avoids aluminum deterioration

• Extremely hard coating

• Similar to sapphire, second hardest substance on earth

• Semi-transparent coating

Anodizing – Multi-Stage Process

• Racking

• Cleaning

• Etching

• Anodize

• Coloring

• Seal Process

Anodize Line

A sophisticated computerized hoist system guides material through the anodize process

Weld Racking

Typically used for stock length extrusions

Clamp Racking

Typically used for cut to size and fabricated pieces

Fixture Racking

Typically used for large volume, identical parts

Anodizing Process – Cleaning

• Alkaline Cleaner

• Removes dirt, water, oils from aluminum surface

• Cleaning process does not remove grease or marker ink

Anodizing Process – Etching

• Immersed in caustic or acid (eco-friendly) bath

• Produces a “matte” finish

• Removed minor scratches and minor die lines

• Will not remove all surface defects

• Etch quality is critical to final appearance because anodize is a semi-transparent coating

• Hides small defects in the aluminum surface, allowing for anodizing of recycled/secondary billet

• Provides a frostier, matte finish

• Lower gloss level, reducing sunlight glare

• Aluminum removed during etch process is reduced by 80%, down to 0.5 mils

• Has the viscosity of water and less likely to collect in small recesses of aluminum extrusions

Eco-Friendly Etch Process

Anodizing Process – Anodic Coating

• Immersed in 15% sulfuric acid

• Charged with electrical dc current

• Aluminum oxide layer formed

• known as clear or satin

• Immersion time = coating thickness

Clear Anodize

Anodizing Process – Coloring

• Champagne, bronze tones, black

• Known as “electrolytic color” or “two-step color”

• All colors in a single tank

• Color dependent on the amount of tin deposited

• Alloy and temper of the aluminum also can affect color

• Amount of tin deposited depends on the time in the tank

• Lightest colors are the toughest to control

Color created by electro-deposition of tin

Anodizing Process – Electrolytic or Two-Step Coloring

Aluminum Substrate

Anodic Pore

Tin Deposit

Anodizing Process – Seal (closing of the pores)

• Immersed in a high purity hydrothermal solution

• Protects anodic coating and coloring from weathering

• Closes and seals the anodic pores

The proper sealing is absolutely essential to

the satisfactory performance of the coating.

The pores must be rendered nonabsorbent

to provide maximum resistance to corrosion

and stains. This is accomplished through a

hydrothermal treatment in proprietary

chemical baths

Anodizing Process – Quality Control Analysis

Champagne

anodize

range samples

Dark bronze anodize range samples

Anodizing Process – Quality Control Tests

• Color

• Visual test to range samples

• Spectrophotometeter (no recommended)

• Coating Thickness

• Isoscope

• Chemistry

• Autotitrator

Anodizing Specifications and Performance

AAMA Anodizing Specification Spec Number: AAMA 611-12

Class I Class II

End Use Exterior Interior or exterior w/regular

maintenance

Film Thickness 0.7 mils 0.4 mils

Salt Spray

Resistance

3000 hours 1000 hours

Color Retention 10 yrs: Fade = 5 Delta E 10 yrs: Fade = 5 Delta E

Industry Product “Labels”

Two-step color Class I

Champagne

Light Bronze

Medium Bronze

Dark Bronze

Extra-dark Bronze

Black

Class I Class II

Clear 215R1 204R1

Strengths of Anodize

• Durability, abrasion resistance

• Metal appearance

• Excellent weatherability (Class I)

Limitations of Anodize

• Limited color choice

• Will not hide surface defects on aluminum (caustic etch process)

• Finish will vary depending on alloy of the aluminum

• Difficult to match anodized sheet with anodized extrusions

• Strong acids/alkalis will quickly deteriorate the aluminum anodized surface

• Field repair is difficult at best, and sometimes not possible

• Chemical attack from acid or alkaline materials - most common occurrence is encountered when mortar or muriatic acid is allowed to dwell, even for a short time

Points to Specify for an Anodized Finish

• Refer to AAMA 611-12

• Class I or Class II

• Color – state “two-step electrolytic”

• Color consistency range <5 delta E

• Eco-friendly (acid) etch process

• creates an aesthetically appealing "frostier" appearance that helps hide small defects in the aluminum

The Painting Process

What is Painting?

• Painting is the application of a protective, decorative organic coating to the surface of a substrate

• Spray Coating Method

• Horizontal paint line

• Vertical paint line

• Coil Coating Method

Painting Multi-Step Process

• Racking

• Pretreatment

• Painting

• Curing

• Quality Assurance

Racking

Pretreatment Process

• Multistage Process

• Cleaning

• Remove surface contaminants, water soluble oil

• Conversion Coating

• Ensures adhesion of the paint

• Adds corrosion protection

• Chrome or chrome-free

Paint Application

• Primer coat (not all paints require a primer coat)

• Color coat / Top coat

• Clear coat (not all paints require a clear coat)

Automatic Spray Bells

Hand Spray Reinforcement

Paint Line in action

Paint Cure Process

• Achieve through baking in a convection oven

• Material must reach peak metal temperature

• Between 350 F to 450 F depending on paint type

• Precision of cure is important for consistent color and gloss

Pigment and Resin left on the Substrate

Resin surrounds

pigment particles

binding them to

the substrate

Solvent escapes

during baking

Primer

Substrate

Quality Control Tests

• Mil thickness

• Color

• Gloss

Quality Control Tests

Spectrophotometers

This instrument

measures color.

This is done to ensure

the project material

matches the approved

color standard.

BYK-Gardner

Color-Guide™ Gloss

This unique instrument

simultaneously measures

color and gloss to make

sure the material meets

the specification.

Quality Control Tests

Test panels can be run with project material.

The AAMA specification tests are then done on

these sample panels to assure a quality

product. The test results should be kept on file

so they can be referenced in the event of a job

site issue.

Some of the tests done are:

•Impact Resistance

•Adhesion (Boiling Water)

•Mortar Resistance

•Acid Resistance

•Mil Thickness

•Pencil Hardness

Test Panels

Job Panels are sent to South Florida for weathering tests

70% Fluoropolymer paint panels cannot fade more than 5 Delta E’s in a period of 10 years, and they

cannot chalk more than a rating of 8 in a 10 year period.

These are critical factors to assure a long-lasting and maintenance free finish

on architectural products.

Environmental Considerations of Paint

• Solvent Vapors (VOC)

• Should be sprayed and cured in a 100% enclosed capture area

• Routed to, and destroyed by, a thermal oxidizer

Environmental Considerations of Paint

• Landfill Waste Reduction

• Applicator should have wastewater recovery system to minimize waste chrome

• Remove all paint-related waste from landfill by fuel-blending and reusing as heat energy

• Utilize paint solvent recycle program

Paint Specifications and Performance

AAMA 2603

South Florida Weathering

Color Retention 1 year – slight fade

Chalk Retention 1 year – slight chalk

Gloss Retention No specification

Erosion Resistance No specification

Dry Film Thickness 0.8 mils minimum

Pretreatment System Chrome or Chrome Free

Accelerated Testing

Salt Spray 1,500 hours

Humidity 1,500 hours

AAMA 2603 Paint Specification

AAMA 2603 is typically an

Interior Specification. Baked

Enamel paints meet the AAMA

2603 spec.

The baked enamel coatings are

harder than the PVDF

(Fluoropolymer) coatings and are

used quite often for interior

application where color retention

is not required. These paints are

less expensive than PVDF paints,

but once again, have poor

resistance to color fading and

chalking.

AAMA 2603 – Baked Enamel Coatings

• Attributes

• Very good hardness

• Achieves AAMA 2603 (only)

• Low cost

• Limitations

• Poor color and gloss retention

• Fair chemical resistance

• Applications

• Interior products

Baked Enamel Systems Manufacturer Trade Names

• Akzo Nobel

• Acro-Bond Plus

• PPG

• Duracron

• Polycron III

• Valspar

• Flurocryl

• Dynapon

AAMA 2604

South Florida Weathering

Color Retention 5 years – 5 Delta E

Chalk Retention 5 years – Chalk = 8

Gloss Retention 5 years – 30% retention

Erosion Resistance 5 years – 10% loss

Dry Film Thickness 1.2 mils minimum

Pretreatment System Chrome or Chrome Free

Accelerated Testing

Salt Spray 3,000 hours

Humidity 3,000 hours

AAMA 2604 Paint Specification

AAMA 2604 is an

“intermediate” specification.

A typical paint to meet this

spec would be a 50%

Fluoropolymer.

A typical application for this

paint would be storefront,

doors and other high traffic

areas. This finish will provide

you with good color and gloss

retention. It will also provide

good hardness and

reasonable abrasion

resistance.

AAMA 2604 - 50% Fluoropolymer Coatings

• Attributes

• Good hardness

• Good color and gloss retention

• Achieves AAMA-2603 and AAMA-2604

• Moderate cost

• Limitations

• Limited gloss range (25-35% reflectance)

• Applications

• Cost-sensitive exterior applications (storefronts, doors, high-traffic areas)

Kynar and Hylar

are not finished

paints, they are

trade names for

the PVDF resin

used in high-

performance

Fluoropolymer

paint coatings

50% Fluoropolymer Coatings Manufacturer Trade Names

• Akzo Nobel

• Aluma-A-Star 50

• Aluma-Escent

• PPG

• Acrynar FX

• Valspar

• Acroflur

• Acrodize

AAMA 2605

South Florida Weathering

Color Retention 10 years – 5 Delta E

Chalk Retention 10 years – Chalk = 8

Gloss Retention 10 years – 50% retention

Erosion Resistance 10 years – 10% loss

Dry Film Thickness 1.2 mils minimum

Pretreatment System Chrome or Chrome Free

Accelerated Testing

Salt Spray 4,000 hours

Humidity 4,000 hours

AAMA 2605 Paint Specification

AAMA 2605 is the

high-end exterior

specification. A typical

paint to meet this

spec would be a

70% Fluoropolymer.

These finishes exhibit

outstanding resistance

to humidity, color

change, chalk, gloss

loss, and chemicals.

A typical application

for this finish is large

monumental

architectural projects.

AAMA 2605 - 70% Fluoropolymer Coatings

• Attributes

• Excellent color and gloss retention

• Excellent chemical resistance

• Achieves AAMA-2603, AAMA-2604 and AAMA-2605

• Limitations

• Limited gloss range (25-35% reflectance)

• Fair hardness

• Higher cost

• Applications

• Exterior products

• Recommended for monumental projects

Kynar and Hylar

are not finished

paints, they are

trade names for

the PVDF resin

used in high-

performance

Fluoropolymer

paint coatings

70% Fluoropolymer Coatings Manufacturer Trade Names

• Akzo Nobel

• Trinar

• Trinar Ultra

• PPG

• Duranar

• Sunstorm

• Duranar XL

• Sherwin Williams

• Shernar

• Valspar

• Fluropon

• Fluropon Classic

• Fluropon Classic II

• Flurospar

Fluoropolymer Paint Coatings

• Kynar 500 & Hylar 5000 are types of fluoropolymer or PVDF resin used in a 70% PVDF resin based coatings that meets the AAMA 2605 specification

• Kynar 500 & Hylar 5000 have a long standing proven track record

• Kynar 500 & Hylar 5000 are the resin part of the paint coating

Resin System

When people describe paint systems, they are typically referring to the resin system incorporated in the paint

Resin System

• 70% fluoropolymer paints – 70% of the resin component is

• 50% fluoropolymer paints – 50% of the resin component is

• Baked enamel – 100% of the resin component is acrylic or polyester

The resin system determines the properties and performance of the paint

Typical gallon of 70% PVDF liquid paint

10% pigment 20% resin 70% solvent

Weatherability • Chalking

• Fading

This is an actual warehouse painted in 1981 with different resin systems

What Causes Chalking Chalking is caused by a degradation of the resin systems at the surface of the finish, due

predominantly to Ultra Violet (UV) rays. As the resin system breaks down, resin particles along

with imbedded pigment

particles lose adhesion

and take on a white

appearance.

Chalking is measured

on a numerical scale.

The higher the number,

the better the chalking

performance.

Failure in the Resin System Causes Chalking

Examples of Chalking

Surface of the paint is breaking down (able to wipe off

with your hand)

A tree brushing against this building has rubbed the paint off

because it had chalked

What Causes Color Fade Fading is caused when substances in the environment attack the pigment portion of the paint

and cause the color to change. Paints that have a high resistance to fading have a lower

reading.

Failure in the Resin System Causes Color Fade

Failure in the Resin System Causes Color Fade

Warranty Information Paint Type Chrome Pretreatment Non-Chrome Pretreatment

Valspar – Fluropon Up to a 20 year warranty

including adhesion

Additional testing and chrome

primer must be used to receive

a 20 year warranty that includes

adhesion

PPG – Duranar Up to a 20 year warranty

including adhesion

No warranty on seacoast

projects. Up to ten years on

other projects

Akzo Nobel – Trinar Up to a 20 year warranty

including adhesion

No adhesion warranty unless

Akzo has tested and approved

the pretreatment system

Fluoropolymer paint suppliers promote Chrome Phosphate pretreatment for the maximum corrosion protection

available.

“Most field failures trace back to improper pretreatment,” says industry expert Manny Mayer. He puts the percentage

at 90% or greater

Points to specify for a painted finish

• Refer to AAMA-2605, AAMA-2604, or AAMA-2603

• Name 70% PVDF resin-based coatings for exteriors

• Specify minimum 40 mg/sq ft chrome pretreatment to ensure maximum long-term adhesion

Environmental Considerations

• VOC’s –Specify all paint applicators must utilize a solvent capture system and thermal oxidizer

• Chrome – Specify all paint applicators must use wastewater recovery system to minimize chrome waste, and applicator complies with all hazardous waste disposal regulations

Strengths of Paint

• Vast choice of color

• Excellent exterior performance (70% PVDF)

• Field touch-up and repainting

• Small batch and custom colors fast and cost effective

• Seacoast performance

• Over 40 years of success in North America

• Available with antimicrobial protection infused in the coating

Limitations of Paint

• Higher cost

• Inconsistent appearance of metallic paints

• Susceptible to scratching, especially the highest-performing 70% PVDF coatings

Powder Coating

What is Powder Coating

• Same basic process as liquid painting

• With the exception of using dry powder rather than wet paint

• A mixture of finely ground particles of pigment and resin, which are sprayed on the surface to be coated

• The dry powder melts and blends in the cure oven

Powder Coating Line

Points to Specify

• Uses the same AAMA specifications as liquid paint. AAMA-2605, AAMA-2604 and AAMA-2603

• Specify minimum 40 mg/sq ft chrome pretreatment to ensure maximum long-term adhesion

Powder Coat Trade Names

AAMA 2603 AAMA 2604 AAMA 2605

Akzo Nobel Interpon D1000 Interpon D2000 Interpon D3000

IFS Coatings Ecuracote 03 Ecoset 04 Fluorset FP / Ecoset 05

PPG Envirocron Duranar

Sherwin Williams Powdera 3000 Powdera 4000 Powdera 5000

Spraylat Arc 2001 Decaflon

Tiger Drylac Series 29 / 17 Series 58 / 68 Series 75

TCI 10000 Series 11000 Series

Strengths of powder coating

• Hardness and scratch resistance – particularly for commercial products like lawn mowers, bike frames and appliances

• Environmentally Friendly – minor VOC emission

• Large job cost may be equal or slightly less than a 70% PVDF liquid coating

Limitations of Powder Coating

• Small custom color jobs

• Warranty - varies by supplier.

• Many are more restrictive and limited as compared to 70% PVDF liquid coatings

• Metallic coatings – can only hold 30% of the metallic flake content as compared to AAMA 2605 liquid coatings

• Touch up – air-dry paint must be matched in a liquid paint for touch-up and field repairs

• Samples and color matches – no in-house blending of powder coatings

• Lead times can be up to 4 weeks

Touch Up Paint

• Does not have the same adhesion or durability as the factory applied coatings

• Will exhibit chalking and fading characteristics noticeably faster

• Should be used as sparingly as possible

• Intended only to cover small blemishes or to touch up exposed cut ends on fabricated parts

Summary Comparison of All Finish Types

Weathering Performance

Finish Options

Paint Systems Anodize Systems

Baked Enamel 50% PVDF 70% PVDF Class II Class I

Color & Gloss Poor1 Good2 Excellent3 N/A Excellent

Chalk Resistance Poor1 Good2 Excellent3 N/A Excellent

Color Options Extensive Extensive Extensive Few Few

Gloss Options 10-90 20-40 20-40 10-804 10-804

Hardness Very Good Good Fair Very Good Excellent

Salt Spray Resistance Poor Fair Good Fair Very Good

Chemical Resistance Fair Good Excellent Fair5 Good5

Effect of Poor Quality Substrate Moderate Moderate Moderate Significant Significant

Initial Cost Low Moderate High Very Low Low

Finish Performance Comparison

1 Meets AAMA-2603 2 Meets AAMA-2603 and AAMA-2604 3 Meets AAMA-2603, AAMA-2604 and AAMA-2605 4 Dependent solely on the individual substrate 5 Except for highly alkaline solutions – very poor performance

Questions

Include this guide specification

for high-performance

architectural coatings

in your Master Spec

Restoration and On-Site Painting Samples for Specified Projects

Copper Anodize Finishes

Antimicrobial Protective Coatings

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