binks spray tips november 2008 surface preparation - general anything you don’t want to see in the...

Binks Spray Tips

November 2008

Surface Preparation - General• Anything you don’t want to see in the final

finish must be removed from the surface

• Surface must be clean • Lint Dirt Oil• Contaminant• Substrate determines pretreatment

The greatest single cause of paint failure is poor surface preparation

Surface Preparation - Trash Defect

Introduction - Why Spray?

• Increase Quality

• Increase Production

• Reduce Costs - Paint and

Labor

• Government Regulations

• Coatings Change

• Maintenance Reduction

Introduction - Have we changed?

Coatings - Wet Film Thickness Gauge

Viscosity - Characteristics

• The Property Of Liquid Which Enables It To Resist Flow

• Measured By The Time Required For A Given Volume Of Liquid To Flow Through A Small Hole In The Bottom Of A Metal Cup Under Controlled Conditions.

• Standardized at 77o F

Viscosity - Cups

• Accuracy Is Best In Middle

Of Cups Range

Types Of Cups• Ford• Fischer• Zahn• DIN• Others

Viscosity - Cups

• Accuracy Is Best In Middle

Of Cups Range

Types Of Cups• Ford• Fischer• Zahn• DIN• Others

Viscosity - Cups Range Specifications

Zahn 1 31- 60 Ford 2 37 - 110

Zahn 2 19- 60 Ford 3 23 - 110

Zahn 3 11 - 60 Ford 4 16 - 120

Zahn 4 10 - 60

Zahn 5 10 - 60

All times in seconds Gardner Company

Viscosity - Cups Range Specifications

Zahn 1 31- 60 Ford 2 37 - 110

Zahn 2 19- 60 Ford 3 23 - 110

Zahn 3 11 - 60 Ford 4 16 - 120

Zahn 4 10 - 60

Zahn 5 10 - 60

All times in seconds Gardner Company

Viscosity - Timing

Atomization - External Mix Air Cap

Atomization - Air Cap Ratings

• Type– Pressure

– Suction

• Finish Material– Type

– Viscosity

– Flow Rate

• Operating Pressure Range

• Air Volume (CFM) Required

Atomization - Internal vs External Mix Caps

Internal External

Air Spray Guns - Three Ways To Feed

• Suction Feed

• Gravity Feed

• Pressure Feed

Air Spray Guns – Fluid Feed Types

Suction Gravity Pressure

Air Spray Guns – Major Components

Atomization - Nozzle Combination

Atomization - Suction Vs Pressure Feed Cap

Suction Pressure

Atomization - Air Cap Selection

• Volume of air (CFM) available

• Material feed system: suction or pressure

• Type and volume of material to be sprayed

• Size of fluid tip

• Size and nature of object being sprayed– (Pattern size)

Spray Gun Technique - Arcing

Spray Gun Technique – Too Far / Too Close

Spray Gun Technique - Gun Distances

Spray Gun Technique – Tilting the Gun

Spray Gun Technique - Vertical

Spray Gun Technique - Pattern Size

Spray Gun Technique - Open Work

Spray Gun Technique - Horizontal

Spray Gun Technique - Wide Mat'l

Spray Gun Technique - Corners

Troubleshooting - Spray GunFluid Leaking from Packing Nut

Packing nut loose

Packing worn or dry

Air leaking from front of gun

Sticking air valve stem

Foreign matter on air valve or seat

Worn or damaged air valve or seat

Broken air valve spring

Bent valve stem

Air valve gasket damaged or missing

Troubleshooting - Spray Gun

Fluid Leaking from Front of GunPacking nut too tight.

Fluid tip or needle worn or damaged

Foreign matter in tip

Fluid needle spring broken

Wrong size needle or tip

Dry packing

Troubleshooting - Spray Gun

Fluttering

Material Level Low

Fluid Passage Obstruction

Loose or damaged fluid tip/seat

Dry or loose needle packing

Material too heavy (suction)

Air vent clogged (suction)

Troubleshooting - PatternsRight/Left - Top/Bottom Heavy

Reverse the air cap 180o. If the problem reverses, the problem is with the air cap. If not, the problem is with the fluid tip/needle.

Troubleshooting - Patterns

Center Heavy

Spreader adjustment in too far

Atomizing pressure too low

Fluid pressure too high

Fluid tip incorrect size for material and flow

Troubleshooting - Patterns

Split Pattern

Fluid needle adjustment in too far

Atomization air too high

Fluid pressure too low

Spray Gun Maintenance – Rule #1

Spray Gun Maintenance - Lubrication

Use Spray Gun Lubricant

Spray Gun Maintenance - Air Cap