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