Evolution of Coating Applications Methods & Technology For Eastern NACE Conference

By Doug KlingensmithPresident of USI NACE Member

268050

Does This Look Familiar? Innovation & Tech has the answers

The First Paints

• Found in prehistoric caves

• Using simple ingredients such as soil water & animal fats

The 3 P’s of Coating Effectiveness

1.Preparation2.Preparation3.Preparation

Substrate Preparation

• Key reminder – The product you are applying is only as good as your preparation.

• Follow application directions from manufacturer.• Follow structure owner specification if available.• Both may include items such as:– Atmospheric conditions

• Moisture• Wind• Humidity• Temperature

Substrate Preparation Continued

– Cleanliness of pipe• Standards by NACE, SSPC, ISO• Structure owner specification

– Anchor pattern• How aggressive?

– Elimination of spurs and sharp edges– Transition issues• Overlap• Tapered edge

Humidity, Temperature – Weather Conditions

Pipe Conditions – Record your findings.

Substrate Preparation

How well did you prepare the steel?

How clean is your air supply?

Blasting set up.

The 3 P’s of Coating are:Preparation, Preparation & More Preparation.

Conventional Grit Blasting

Newly Developed Bristle Blasting

Pneumatic Electric

MBX Bristle Blaster

APPLICATION EQUIPMENTAPPLICATION EQUIPMENT

• Before we examine the various Application Equipment available, we must first consider the following:

– SHAPE AND SIZE OF THE OBJECT TO BE COATED• (SPEED OF APPLICATION / MASKING / CUTTING IN)

– VISCOSITY OF THE MATERIAL (GRADE OF MATERIAL FROM HVLP SPRAY TO TROWL GRADE)

– APPLICATION PROPERTIES OF THE MATERIAL (SINGLE OR 2 PACK MATERIAL / POT LIFE / MIXING / WFT REQUIED)

– WHAT CONDITIONS ARE LIKELY TO AFFECT THE APPLICATION AND FINISH OF THE COATING? (REQUIDED DFT / FINISH REQUIRED / PERCENTAGE OF THINNER ADDED, SURFACE CONDITION, NUMBER OF COATS)

BRUSH & ROLLER

• Advantages:– Techniques are relatively simple

to master.– Equipment cost is low.– 100% “Transfer Efficiency”.– Negligible lost of product due to

equipment.• Disadvantages:– Application is relatively slow.– Difficult to eliminate Brush

Marks or “Orange Peel” from roller application.

BRUSHES• To achieve a quality finish, use a quality brush. Forked bristles

with a good “stock”.

• For very viscous materials, the brush may be cut down to aid application.

• Achieving an acceptable and smooth finish when brushing can be a difficult. A lot depends on the properties of the coating material, the dimensions of the work, and the skill of the operator.

• The operator must try to maintain an “open” edge to be able to work with the “Wet Edge Time” of the material. Also, when painting vertical surfaces, “Laying Off” vertically on the final stroke will aid flow.

ROLLERS

• The choice of rollers is increasing all the time. Both the “SLEEVE” material and its “PILE” can be chosen to suit a particular application.

• APPLICATION ROLLERS: – Such as, Mohair, Wool, High Density Foam, Nylon

etc.

• EFFECT ROLLERS: – Such as, Sponge, Stipple, – Rag, etc.

Application Continued• Hand Applied– Bell hole application– Girth weld application– Risers– Anywhere spray

application is not needed or possible

Coating Tips

• Don’t forget about the pot life of the product.

•Man is my wrist sore. Where is the power mixer?

MIXERS• DRILL and • EPI-MIXER

• For mixing at High Speed.

• Good for mixing Larger Units of “Liquid” Coating or small quantities of screeds.

• Particularly if the Pot Life is Short, or the coating is difficult to mix by hand.

Coating Technology Applications

Two-Part Epoxy Application

• Cartridge Format– Pinhole repair– Small diameter field

joint– Small scrapes and

abrasions– Test lead repair kit

Coating Tips

• Icicle formation at the 6:00 position due to improper roller application.

• Difference between spray application and roller application.

SPRAY APPLICATIONS• Many types of equipment are available. Choice depends mainly on

the viscosity of the product to be sprayed, and the working environment.

• Advantages over Brush & Roller Application ?– Spray Application is much quicker.– Reduced labor costs.– Quality of finish is higher.

• Disadvantages ?– Use of equipment and techniques is more skilled. – Equipment can be very expensive.– Transfer Efficiency is lower than 100 %– More loss of product due to equipment.

Method of Atomization• TABLE OF GENERAL PROPERTIES FOR SPRAY EQUIPMENT

Application Equipment

Material Viscosity

WorkingPressure

Application Speed Atomization Quality Transfer Efficiency

Conventional Air Spray Low - Medium 40 - 100 psi Medium - Fast Excellent 35 - 45 %

HVLP Low 40 - 80 psi Slow - Medium Good - Excellent 45 - 70 %

Airless Spray Medium - High 1500 - 5000 psi Very Fast Fair 55 - 80 %

Air Assisted Airless Medium - High 500 - 1500 psi Fast Good 55 - 75 %

Wet Electrostatic(Induction)

Low 40 - 80 psi Medium Good - Excellent 60 - 80 %(+ 5-20 %)

Conventional Air Spray• Used for “FINE FINISHES”. • Eg: Trains / Automotive / Furniture Applications Disadvantages:

Very Poor Transfer Efficiency Due to High Bounce Back.

ATOMIZATION

AIRLESS SPRAY GUN• Coating is pumped under EXTREME

pressure through an ORIFICE.

• This action ATOMIZES the paint AND produces the FAN, without the use of air at the tip.

• The Airless Spray Motor may be driven by compressed air or electricity.

Typical Unit

Changing Fan Pattern

Airless Spray Application– Handles Medium to High

viscosity materials. – Application Rates are

very high.– Used for “INDUSTRIAL

FINISHES”. Eg: Bridge / Ship / Structural Steel Coating.

– Very Good Transfer Efficiency Achieved.

– Can only be used for 2 Pack materials if the “Usable Life” is long.

PLURAL FEED HOT AIRLESS SPRAY

• These units are used to spray –2 Pack materials that have a short “Usable

Life” or –2 Pack materials that are too viscous to

spray at ambient temperatures.

For example:–Many solvent free 2 component Epoxies

or Polyurethane's

Plural Hot AS Schematic

Epoxy Unit

Fast Set Polyurethane Unit

PLURAL COMPONENT GUNS

• Various plural component guns are available

SOLVENT FREE EPOXY APPLICATION

• Graco Xtreme Mix Plural-component spray machine

Gracy Xtreme MixPlural Unit

Epoxy Application Clip

• Spray Applied– Large rehab projects– Plural component

spray– Economical

•Advantages ?– Materials may be easily

heated.– Short Usable Life’s are

not a problem.– Negligible waste.– Higher material

temperature provides faster working rates and better atomization.

– Shorter and fewer down times.

•Disadvantages ?– Units are very

expensive (but may be hired).

– Operation of units is more skilled. (Requiring 2 operatives).

– Equipment is bulky.– Larger compressors

required.– Longer start up times.

Plural Feed Spraying

High-solids, cartridge spray systems save time. Ideal for jobs that are too

small for Plural Spray

A 450mL cartridge can cover 6 to 7 sqft at 25-40 mils.

Intended Uses

• As a patch material• As a girth weld coating• As an internal lining• As a stand alone coating for pipe

rehabilitation• In a wide variety of other field applications

where corrosion protection of metal is required

Q & A

• Various Application Equipment• Brush & Roll• Conventional Spray• Heated Plural Spray Units• Portable High Solids Cartridge Spray

Summary

• Correct selection of application equipment with fully trained personnel can result in a fast, stress free application which in turn will result in a better quality finish.

• This in turn will lead to better protection and reliability of your valued assets and minimize potential issues with the DOT or the public

• Lowering your company’s Life-Cycle Cost and increasing corporate long-term profits.

Thank YouDoug Klingensmith

NACE Member268050