Troubleshooting Guide

TROUBLESHOOTING GUIDE

Power Supply Problems

Trouble		Causes		Solutions
FLUIDIZED BED
1	Dusting – Powder blowing out of the hopper.	I	Air pressure too high	I	Adjust air regulator to lower pressure in the fluid bed.
1	Dusting – Powder blowing out of the hopper.	II	Powder too fine	II	Reduce the amount of reclaim added to virgin powder.
2	Ratholing – air blowing large jet holes through the powder surface.	I	Powder level too low	I	Add powder until the hopper is 2/3 full when fluidized.
		II	Packed or moist powder.	II(A)	Manually loosen the powder and fluidize it well with clean dry air.
		II	Packed or moist powder.	II(B)	Check compressed air for high humidity.
		III	Obstructed membrane.	III	Check the bottom of the bed for plastic, cardboard, or other large obstructions.
		IV	Blocked or broken membrane.	IV	Check the membrane for blocked pores from dirty air supply, cracks, or holes.
HOSES AND PUMP VENTURI TUBES
3	Blocked from Fusion – Hard Buildup	I	Normal buildup	I	Clean or replace parts.
		II	Air pressure too high	II	Turn down air settings on pumps and guns.
		III	Moisture in air supply	III	Check the air supply for clean, dry air.
		IV	Composing of powder feed hoses	IV	Check hoses.
		V	Worn venturi tubes and wear parts	V	Replace worn parts.
		VI	Powder too fine	VI(A)	Reduce the amount of reclaim added to virgin powder.
		VI	Powder too fine	VI(B)	Check the particle size of virgin powder.
		VII	Powder type or formula.	VII	Some resin types tend to have more impact fusion. Check with your powder supplier.
RECLAIM EQUIPMENT
IV	Contamination in reclaim powder	1	Reclaim in-line sieve torn, missing, or inoperable.	1	Repair sieve or replace if necessary.
		II	Powder or dirt falling in the spray booth from conveyors or hangers	II	Clean conveyor regularly (or continuously) before it enters the powder spray booth, strip hangers as needed.
		4	Contamination of parts entering spray.	III	Check cleaning and pretreatment equipment and ensure proper part drainage before the part enters the spray booth.
		IV	Contamination from plant air circulated through the spray booth.	IV	Isolate the spray booth area. Preferably, enclose it in a room with filtered, humidity-controlled air.

Cured Finish Appearance Problems

Powder Application Problems

Trouble		Causes		Solutions
1	Poor charging – inadequate powder buildup or wrap-around	I	High voltage source not providing enough KV at charging electrode or grid.	I(A)	Check if the high voltage source is on. Systematically check electrical continuity from the voltage source to the electrode (grid), including cables, resistors, and fuses.
				I(B)	Replace missing or broken electrode (grid).
				I(C)	Clean electrode (grid) insulated by powder buildup or impact fusion.
		II	Poor earth.	II	Check earth from conveyor rail (or rub bar when used) through hanger to part. All contact areas must be free of powder buildup, heavy grease, and other insulating material.
		III	Powder delivery (feed) is too high.	III	Turn down powder feed until all material passing through the charging corona (field) is adequately charged.
		IV	Excessive moisture in powder and air.	IV	Moisture in humid air will tend to dissipate the charge on the powder particles. Control the humidity in the powder spray area.
		V	Powder too fine.	V	Reduce the amount of reclaim added to virgin powder.
		V	Powder too fine.	V	Check particle size of virgin powder.
		VI	Powder type or formula.	VI	Some resin types charge better than others, and some formulas are designed for low film application. Check with your powder supplier.
		VII	Powder delivery air too high.	VII	Turn down air setting or move gun position further away from the part.
2	Poor penetration – powder will not coat Faraday cage area (holes, grooves, channels, inside corners, and recesses).	I	Powder delivery too low.	I(A)	Turn up powder delivery air setting.
		I	Powder delivery too low.	I(B)	Use gun barrel extension.
		II	Poor earth.	II	Check earth. See powder application problems, poor charging section, cause 2.
		III	Powder spray pattern too wide.	III	Select a smaller deflector or use a suitable slotted barrel end cover. Consult your equipment supplier.
		IV	Voltage too high.	IV	Turn voltage setting down so powder builds on part edges and leading surfaces do not repel powder from corners.
		V	Powder velocity too high.	V	Turn air settings down so powder/air stream does not blow powder out of corners.
		VI	Poor gun placement.	VI	Adjust gun position so powder cloud has a direct path to recess.
3	Backionization – Powder layers are repelled from the part in spots.	I	Voltage too high.	I	Turn down voltage setting.
		II	Gun positioned too close to the part.	II	Charge gun placement further away from the part.
		III	Poor earth.	III	Check earth. See powder application problems, poor charging section, cause 2.
4	Powder feed surging or spitting – interrupted powder feed.	I	Insufficient air pressure or volume.	I	Check air supply piping to equipment is large enough. Enough air volume must be provided so that when other equipment such as reverse air cleaning in reclaim housing pulses. Air pressure to powder feed does not drop.
		II	Hoses kinked, flattened, or too long.	II	Check powder feed hoses. See powder supply problems, insufficient feed, cause 2.
		III	Hose pump venture tubes or guns clogged with powder.	III(A)	Clean hose, venturi tubes, and guns.
				III(B)	Check air supply for moisture that causes powder compaction.
				III(C)	Check powder flow properties.
				III(D)	Check spray booth air humidity.
5	Poor spray pattern. Not a symmetrical powder cloud (not applicable using special deflectors for the desired effect).	I	Worn E/S Gun parts	I	Replace worn feed tubes, on surfaces, deflectors, and covers.
		II	Impact fusion build.	II	Check gun parts as needed.
		III	Delivery (feed) too low.	III	Check air supply, increase air for powder feed.
		IV	Hoses, venturi tubes, or gun blocked with powder.	IV	Clean hoses, venturi tubes, and guns.

Trouble Shooting Tips To Maximize The Benefits Of Powder coatings :

Powder Application Problems

Trouble		Causes		Solutions
1	Poor charging – inadequate powder buildup or wrap-around	I	High voltage source not providing enough KV at charging electrode or grid.	I(A)	Check if the high voltage source is on. Systematically check electrical continuity from the voltage source to the electrode (grid), including cables, resistors, and fuses.
				I(B)	Replace missing or broken electrode (grid).
				I(C)	Clean electrode (grid) insulated by powder buildup or impact fusion.
		II	Poor earth.	II	Check earth from conveyor rail (or rub bar when used) through hanger to part. All contact areas must be free of powder buildup, heavy grease, and other insulating material.
		III	Powder delivery (feed) is too high.	III	Turn down powder feed until all material passing through the charging corona (field) is adequately charged.
		IV	Excessive moisture in powder and air.	IV	Moisture in humid air will tend to dissipate the charge on the powder particles. Control the humidity in the powder spray area.
		V	Powder too fine.	V	Reduce the amount of reclaim added to virgin powder.
		V	Powder too fine.	V	Check particle size of virgin powder.
		VI	Powder type or formula.	VI	Some resin types charge better than others, and some formulas are designed for low film application. Check with your powder supplier.
		VII	Powder delivery air too high.	VII	Turn down air setting or move gun position further away from the part.
2	Poor penetration – powder will not coat Faraday cage area (holes, grooves, channels, inside corners, and recesses).	I	Powder delivery too low.	I(A)	Turn up powder delivery air setting.
		I	Powder delivery too low.	I(B)	Use gun barrel extension.
		II	Poor earth.	II	Check earth. See powder application problems, poor charging section, cause 2.
		III	Powder spray pattern too wide.	III	Select a smaller deflector or use a suitable slotted barrel end cover. Consult your equipment supplier.
		IV	Voltage too high.	IV	Turn voltage setting down so powder builds on part edges and leading surfaces do not repel powder from corners.
		V	Powder velocity too high.	V	Turn air settings down so powder/air stream does not blow powder out of corners.
		VI	Poor gun placement.	VI	Adjust gun position so powder cloud has a direct path to recess.
3	Backionization – Powder layers are repelled from the part in spots.	I	Voltage too high.	I	Turn down voltage setting.
		II	Gun positioned too close to the part.	II	Charge gun placement further away from the part.
		III	Poor earth.	III	Check earth. See powder application problems, poor charging section, cause 2.
4	Powder feed surging or spitting – interrupted powder feed.	I	Insufficient air pressure or volume.	I	Check air supply piping to equipment is large enough. Enough air volume must be provided so that when other equipment such as reverse air cleaning in reclaim housing pulses. Air pressure to powder feed does not drop.
		II	Hoses kinked, flattened, or too long.	II	Check powder feed hoses. See powder supply problems, insufficient feed, cause 2.
		III	Hose pump venture tubes or guns clogged with powder.	III(A)	Clean hose, venturi tubes, and guns.
				III(B)	Check air supply for moisture that causes powder compaction.
				III(C)	Check powder flow properties.
				III(D)	Check spray booth air humidity.
5	Poor spray pattern. Not a symmetrical powder cloud (not applicable using special deflectors for the desired effect).	I	Worn E/S Gun parts	I	Replace worn feed tubes, on surfaces, deflectors, and covers.
		II	Impact fusion build.	II	Check gun parts as needed.
		III	Delivery (feed) too low.	III	Check air supply, increase air for powder feed.
		IV	Hoses, venturi tubes, or gun blocked with powder.	IV	Clean hoses, venturi tubes, and guns.

Cured Finish Physical Problems

Trouble		Causes		Solutions
1	Poor impact resistance, poor flexibility.	I	Undercured	I(A)	Increase oven temperature.
		I	Undercured	I(B)	Increase dwell time in the oven.
		II	Poor cleaning or pretreatment	II	Check pretreatment equipment and chemicals.
		III	Film thickness too high	III	Reduce film thickness by adjusting application equipment.
		IV	Change in substrate thickness or type.	IV	Check substrate with supplier.
		V	Powder resin type or formula	V	Check with powder manufacturer.
2	Poor adhesion	I	Poor cleaning or pretreatment	I	Check pretreatment equipment and chemicals.
		II	Change in substrate	II	Check substrate with supplier.
		III	Undercured	III(A)	Increase oven temperature.
		III	Undercured	III(B)	Increase dwell time in oven.
		IV	Powder resin type	IV	Check with powder manufacturer.
3	Poor corrosion resistance	I	Poor cleaning or pretreatment	I	Check pretreatment equipment and chemicals.
		II	Undercured	II(A)	Increase oven temperature.
		II	Undercured	II(B)	Increase dwell time in oven.
4	Poor chemical resistance	I	Undercured	I(A)	Increase oven temperature.
		I	Undercured	I(B)	Increase dwell time in oven.
		II	Powder resin type or formula	II	Check with powder manufacturer.
5	Poor pencil hardness / poor abrasion resistance	I	Undercured	I(A)	Increase oven temperature.
		I	Undercured	I(B)	Increase dwell time in oven.
		II	Powder resin type or formula	II	Check with powder manufacturer.

Dusty Coating & Poor Mechanical

Sr. No.	Problem type	Possible cause	Solutions
1	Dusty coating	Higher percentage of sludge in phosphate bath, poor rinsing	Clean and filter the bath, improve water rinsing
2	Poor mechanical	Poor degreasing, higher thickness, and coarse phosphate coating, passive metal	Improve degreasing, check activation bath, dipping time, and accelerator in phosphate bath, improve metal reactivity

TROUBLESHOOTING GUIDE

Powder Application Problems

Powder Application Problems

Quick LInks

Manufacturing Facility

Branch Offices

Mail us at (Sales)

Social Media