Troubleshooting Guide - TIGER Coatings

2.4 Poor Wrapping Scenario: With one sided gun positioning only minimal film thickness can be achieved on opposite side.Possible causesCorrections, testing, proceduresPowder flow too low or too highOptimize system parameters, adjust air flowTemperature of the part too high after dry-off oven or preheatingAllow adequate time for cooling (less than 40 C / 104 F]Insufficient groundingUse clean hooks, test transfer resistance ( 1 MW), checkdiameter of hooksSupplemental air flow is too high or too lowAdjust air speed and powder cloudUnsuitable particle size distributionConsult powder manufacturerInsufficient charging of the powderAdjust high voltageGun voltage too highPoor or wrong positioning of the partsGun defectiveAdjust voltage to suit part geometryAdjust hanging configurationConsult equipment and powder manufacturerImg. 2.4.1. Poor wrap-aroundImg. 2.5.1. Powder lumping in the box2.5 Powder lumping in the box Scenario: Lumping in the powder coating in powder boxPossible causesCorrections, testing, proceduresInappropriate storage (temperature too low/too high, inexcess of shelf life)Strain before use, use fresh powderTransport too slow or too warmStrain powder before use, consult powder manufacturerBox feedingAvoid continuous vibratory operationTIGER Coatings GmbH & Co. KG Negrellistraße 36 4600 Wels Austria T 43 / (0)7242 / 400-0 office@tiger-coatings.com www.tiger-coatings.com

2.6 Poor penetration into recesses Scenario: Despite the physical conditions (faraday cage), it is possible to achieve a minimum coating thickness in the corners.With poor penetration procedures penetration depth is very limited. Extreme film thickness variations are noticeable.Possible causesCorrections, testing, proceduresFeed supplemental or tribo air too highChange of lower pressurePowder flow too highAdjust equipment controls to suit partAir speed too highNot enough powder flowAdjust equipment controlsAdjust/optimize equipment parametersInappropriate application, unsuitable nozzleUtilize flat spray nozzle or deflector; Adjust nozzleVoltage too highAdjust/reduce voltageInsufficient charging of powder, defective gunFaraday cage effect due to electric fieldAdjust voltage (increase, test)Contact equipment manufacturerUse tribo equipment and powder; Reduce voltageInsufficient groundingUse clean hooks, test transfer resistancePowder spray too wideUse different gun nozzle of deflectorUnsuitable particle size distributionOptimize through testing; Contact powder manufacturerDistance from gun to part is too big or too smallIncrease or decrease distanceImg. 2.6.1. Additional earthing for hollowsImg. 2.6.2. Rip up caused by poor metal-productionSeite 1110-2016

2.7 Film Thickness too high Scenario: Powder coat layer shows uneven surface prior to curing, after curing shows orange peel, wavy flow, or pinholes.Possible causesCorrections, testing, proceduresParts are too hot coming from dry-off ovenAllow longer cooling time (less than 40 [ C] / 104 [ F]) for partsPowder flow too highLower powder feedPreheat temperature too highCoating time too longLower preheat temperature or allow for cooling (less than40 [ C] / 104 [ F])Lower coating timeUnfavorable geometry of partsChange hanging or gun configurationGun-to-part distance too closeImg. 2.7.1. Film thickness too high (ornateness)Increase gun-to-part distanceImg. 2.7.2. Too thick powder cloud2.8 Film thickness too low Scenario: Substrate shows through and powder coat has grainy flow.Possible causesCorrections, testing, proceduresInsufficient charging of powderTest and adjust voltagePowder flow too lowIncrease powder flowInappropriate particle size distribution/percentage of overspray too highPowder delivery hose too longContinuous and even introduction of virgin powder toreclaim powder; Patio adjusted to actual consumptionOptimize particle size distribution through testingShorten hose; Change hose diameter; Change injectorFluid characteristics of powder not optimalCheck fluidization (see 2.1 poor fluidization)Suction of reclaim system too highLower suction capacityResidence time of parts in front of gun too shortBooth draft too strong to allow powder cloud to deposit onits ownChanged powder supply due to powder deposits in thetransport system, injectors, hose and nozzlePlugged transport system due to foreign materials(e.g. fibers, cleaning residues)Slow down line speed of conveyor; Increase number ofpasses of gun in front of part; Add more gunsChange system configuration; Consult with booth supplierSlow down line speedCleaning of the transport system components, coordinatefeed and atomized air, check fluidizationCommit to cleaning cycles and regular maintenanceInappropriate hanging of partsCheck and adjust hanging configurationInsufficient groundingUse clean hooks; Avoid thin hooks (note voltage loss)Check transfer resistance if systemProcessing of non Tribo powders in Tribo systemsUse Tribo powderTIGER Coatings GmbH & Co. KG Negrellistraße 36 4600 Wels Austria T 43 / (0)7242 / 400-0 office@tiger-coatings.com www.tiger-coatings.com

Possible causesCorrections, testing, proceduresLow level of powder in fluid hopperReplenish powder; Check minimum indicatorToo much overspray in booth due to cleaning cyclesRegular transport of overspray from booth to reclaim systemInsulation of base coat too strongReduce voltage for second coat and lower powder flowUse tribo powder coatingsParticle size too fine due to circulation in systemIntermittent back pulse of filter too long, sudden shift ofpowder particle size (too fine)Gun-to-part distance too highPowder hose causes friction charge of opposite polarity tocharge generated in gunIncrease virgin to reclaim ratioKeep back pulse of compressed air short (e.g. 20 seconds)Reduce distanceChange hose material or ground hose2.9 Film build varies Scenario: Substrate shows through and powder coat has grainy flow. Or powder coat shows uneven surface prior to curing– orange peel after curing, wavy flow, pinholes. These appearances vary on the surface of the work piece.Possible causesWrong positioning of guns in an automated systemInappropriate insulation of base coatCorrections, testing, proceduresEmpirical determination of proper gun positioning.Optimize interval curve of automatic guns. Check conveyor/lift speedAdjustment of hanging or gun configuration Additional groundingNo continuous, even introduction of virgin powder to reclaim powder based on actual consumptionAssure proper functioning of recovery system Adjust virginto reclaim ratioFlapping/swinging of the work piecesAdjust hanging configuration, Test fastening methodUnfavorable geometry of parts (Faraday Cage)Change hanging configuration or gun positioning Use flatspray nozzlesSliding of powder film (in an improperly fused condition)due to conveyor vibrationUneven powder transportGeometry of parts varies greatlyInspect conveyor and chain, Test grounding/chargingTest powder transporting devices for clogging due to foreignparticles or plugs, Test for air pressure variationsOptimize device and gun adjustments to suit work pieceExcessive manual touch-upAdjust automatic guns or possible pre-coatUneven manual touch-upIf possible pre-coat, Train personnelImg. 2.9.1. Unsteady film thickness because of wrong mounting (to narrow distances)Seite 1310-2016

3 Surface Defects3.1 Powder puffs on the work piece Scenario: Powder puffs are powder clusters that in an improperly fused condition are visible as powder hills in the powderfilm. After curing these powder puffs appear as disturbing elevations on the surface.Poor fluidizationPossible causesCorrections, testing, proceduresPowder hose too long or diameter too largePowder too fine (reclaim)Uneven transportSee section 2.1 (poor fluidization)Change hose diameter, Shorten hose, Change configurationAdd virgin powderTest air pressure, Check for pressure variationsClogging of the feed hosesNote hose path, see section 2.2. (clogging of the powderfeed hoses)Powder falls off booth ceilingAdjust/increase frequency of booth cleaning intervalsPowder falls off hanging devicesRemove/ reduce powder coat layer, check groundingPowder build-up on deflector plateCheck atomized airPowder falls off work pieceTest grounding, Check diameter of hosesCatch nozzle wornChange nozzleAir pressure variations in powder supply systemAdjust air pressureLevel in powder supply container varies greatlyReduce distance between minimum and minimum levelGun nozzle defectiveCheck nozzle, replacePowder moistUse dry powder; Check for condensation (temperature difference from powder storage area to coating area), Check airfilter and moisture traps in compressed air systemImg. 3.1.1. Filter residues cause powder spittersImg. 3.2.2. Powder spitters on the cured powder surfaceTIGER Coatings GmbH & Co. KG Negrellistraße 36 4600 Wels Austria T 43 / (0)7242 / 400-0 office@tiger-coatings.com www.tiger-coatings.com

3.2 Craters Scenario: defect – blank area in the powder coat, which extends all the way to the substrate (diameter up to 2 mm).Possible causesCorrections, testing, proceduresInsufficient pretreatment (e.g. oil and grease residues)Test pretreatment if necessary, contact pretreatment supplierRust, white rust on partsAssure clean surface, apply recommended pretreatment,possibly buff or sandblast (sweep) surfaceChemical residue, faulty pretreatmentOil in feed and/or atomizing airTest pretreatment, if necessary contact pretreatment supplierCheck in-line filters and moisture traps in air systemSilicones from chain lubricants or welding spraysUse product without silicon content, educate line operatorsOutgassing from substratePre-heat work pieces, use OGF additiveIncompatibility with powder coatings from other manufacturersSurrounding air contaminatedCleaning of coating and application equipment, contactpowder coating supplierBalance air flows in plant, avoid cross draftsSpin-off-products at the cross-linkage of the powder coating Adjust the powder coating, Consult powder manufacturer,in the curing ovenProvide enough air circulationWork piece moist/wetIncrease drying time/temperatureNote material thickness especially with anodized partsLiquid and powder paint in same plantDefinitely avoid - reconfigure plantBody filler or other compounds not compatibleForced drying, test suitabilityBase coat was cleaned with solventsPreheat work piece or avoid solventsBlasting media decontaminates surfaceDo not reclaim blasting mediaBack ionization effectAdjust application, use tribo if possibleInstead of rough texture effect only penetration-to-metaland craters visibleInsufficient coating thicknessImg. 3.2.1. Crater caused by oil in the compressed airImg. 3.2.2. Crater caused by oil residueSeite 1510-2016

3.3 Pin Holes Scenario: surface defects – development of fine pores on the surface,also leads to change in gloss levelPossible causesMoisture content of powder too highPre-reaction of powder coatTrapped airFilm build too highIncompatible with other powder coatingsWith rough textures, instead of effect development onlypinholes developVery porous work piecesOut-gassing from porous work pieces (cast parts, zinc galvanized material, magnesium castings, anodized materials)Corrections, testing, proceduresTesting through drying of powder/test storage conditionsIn cold climates, watch for condensation in powder (coldstorage area to warm coating area)Check storage parameters, storage time exceededConsult powder manufacturerCheck heat up curvePossible slow heat up curveModify powder coatingNote recommendations of powder manufacturerMinimize film thicknessClean equipment/boothConsult powder manufacturer (if necessary change)Film thickness too low (see 2.8 film thickness too low)Check for satisfactory work pieces, possible surface is toorough from sand blastingPreheat partsModify powder coatingCast anodized materials not scaled and driedImg. 3.3.1. Pinholes caused by too coarse steel resourcesTIGER Coatings GmbH & Co. KG Negrellistraße 36 4600 Wels Austria T 43 / (0)7242 / 400-0 office@tiger-coatings.com www.tiger-coatings.com

3.4 Picture framing effect Scenario: Higher film build of coating on the edges of the part due to wrap, therefore uneven flow.Possible causesCorrections, testing, proceduresPowder particles too rough/unsuitable for particular applicationStrain powder to optimize particle distributionConsult powder coating manufacturerDistance from gun to work piece too lowAdjust/increase distanceVoltage too highAdjust voltage to suit partUneven film thickness, especially in fine textures or metalliccoatingsFeed air/powder flow too highImg. 3.4.1. Boil up of the coating caused by a too high film thicknessAdjust parameters or work piece suspensionAdjust powder flowImg. 3.4.2. Bacon edge at the same film thickness on materials with 0,7 resp. 3 mm3.5 Elevations, Enclosures (other colors), Contaminations Erscheinungsbild: im Pulverlackfilm eingelagerte Fremd- oder Pulverlackpartikel (andersfarbig)Possible causesCorrections, testing, proceduresContamination through conveyor chain or chain lubricationetc.Cleaning of the equipment/check sieve for contamination ortearsFibers from broom and cleaning clothsUse suitable cleaning apparatus and materialsContamination of powder surface due to airborne dirt fromoutside of booth (e.g. surrounding air, floor, polishing area,blasting areaIsolate booth area, clean surroundings with vacuumAvoid cross draftsBalance air flows in plantAvoid polishing in booth and oven areaInsufficient polished welding areas, metal shavings, welding Control finishing process- repeat if necessary Improve polidrops, milling flawsshing stage and pretreatmentContamination from equipment cleaningDeposits from dust and powder particles in the oven (toomuch convection inside, powder that doesn’t adhere, isblown onto work pieces of different colors)Deposits of dust and powder on cured work piecesVacuuming is more effective than compressed air (powder isnot airborne)Reduce air speedInstall pre-gelling curing stageDo not cure other colors at the same time in ovenDust free cooling zoneAvoid draftsSeite 1710-2016

Possible causesDirt and color particle transfer between adjoining boothsContamination from warehousingInsufficient cleaned guns and hosesCorrections, testing, proceduresIf possible reconfigure areaEnclose boothsAssure orderly warehousing, Close powder bags and boxes,Separate by powder typeCareful cleanining of guns and hosesImg. 3.5.1. Bead of sweat on a work pieceImg. 3.5.2. Surface defect caused by a foreign bodyImg. 3.5.3. Fibers in the powder coating surfaceImg. 3.5.4. Clothing fiber in the powder coating film (cured)Img. 3.5.5. Bitter pits caused by metal sliver in the undergroundImg. 3.5.6. Uneven surface caused by poor zinc coatingTIGER Coatings GmbH & Co. KG Negrellistraße 36 4600 Wels Austria T 43 / (0)7242 / 400-0 office@tiger-coatings.com www.tiger-coatings.com

3.6 Blistering Scenario: Elevations of differing size in the powder coat, no adhesion due to enclosures at the part surface.Water on work piecePossible causesCorrections, testing, proceduresCheck dryer and hanging configurationWater in scooping type of work piecesNote geometry, drying time and temperature or changehanging configuration; Air blast work piecesCorrosion, oil and grease residuesOptimize pretreatmentOver coatingAssure flawless first coatOver coating of liquid paintCheck suitability of base coatOver coating of filler areasSalt residues or chemical remnants on the work piece surface, insufficient wettingFilm thickness too high, powder accumulations, powderdrizzles off work piece on edges and cornersDry or cure filler; Check suitabilityCheck pretreatment, final rinse stage, and drying of media/chemicals during transport inactionCheck system parameters; Reduce film thicknessBreak in zinc layer, double zinc layer, corrosion under the zinc Avoid double zinc layers; Ensure flawless zinc layerlayerImg. 3.6.1. Corrosion as bubble causaleImg. 3.6.2. Bubbles caused by corrosion after pretreatmentImg. 3.6.4. Bubbles caused by corrosion after pretreatmentImg. 3.6.5. Bubbles caused by tassels in the galvagnized plateSeite 19Img. 3.6.3. Bubbles caused by outgassing at the die-cast aluminium10-2016

3.7 Drip Developments Scenario: Running or dripping of the gelling powder coat off the work piecePossible causesFilm thickness too high (with wire or sheet metal parts)Corrections, testing, proceduresReduce film thicknessPowder slides to the edgeIncrease voltage; Check groundingHeat up rate too high or inappropriateReduce heat up speed; Control oven temperatureSubstrate temperature is too high (from preheating ordryer), therefore film build too highPowder accumulation on inside corners from drizzled offpowder coatingImg. 3.7.1. Drop formation caused by a too high film thicknessIncrease cooling time (max. 40 [ C] / 104 [ F]) between dryoff oven and booth; Optimize film thicknessOptimize system parameters and blast off effectImg. 3.7.2. Drop formation3.8 Orange peel Scenario: Poor flow (orange peel look), short or long waviness of powder coat layer, noticeable only after curing.Possible causesHeat up cycle of parts too slowCorrections, testing, proceduresDetermine heat up curve and increase (especially with partsof high wall thickness)Substrate temperature exceeds the melt temperature of the Check substrate temperature (max. 40 [ C] / 104 [ F])powder, causing excessive film buildIncrease cool down phasePowder coating material too reactiveConsult powder manufacturerUnsuitable particle size distributionOptimize particle size distribution; Consult powdermanufacturerShift in particle size distribution, portion of reclaimedpowder too highFilm thickness too high or too lowIncompatibility with other powder coatingsPowder stored too long/pre-reactedVoltage too highUneven wall thickness (thick to thin)Back ionization effectTextured work piece surfaceAir speed too high at oven entranceOptimize deposit results of powder gunsIncrease lift intervalsCheck system parametersClean booth, check compatibilityConsult powder manufacturerCheck storage.If powder is too old, exchangeOptimize voltage; Change to low ionizing application ortribo gunsOptimize oven temperatureReduce voltage; Increase distance from work piece to gunOptimize texture, check work piece surfaceReduce air speed (max. 0

Film build too high Check geometry of part Reduce powder flow . Powder flow too low or too high Optimize system parameters, adjust air flow . Temperature of the part too high after dry-off oven or pre-heating Allow adequate time for cooling (less than 40 C / 104 F] Supplemental air flow is too high or