Powder Coating Tips

HotCoat Powder Coating Tips and Usage

Required Items  |  Work Area Setup  |  Preparing the Part  |  Curing Prep   |  Preparing to Powder Coat Application of Powder  |  Curing the Powder  |  Clean-Up  |  Reusing the Powder  |  Removing Cured Powder Warnings & Safety Tips  |  Environmental Concerns  |  Troubleshooting  |  Powder Coating 101  

Required Items

Before you use the HotCoat™ Powder Coating System make sure you have the following:
  • An electric oven or toaster oven large enough to fit the parts you will be coating. Do not use an oven used for food preparation or located in a living area! Do not use a gas oven.
  • An air supply source for the gun. A modest air compressor capable of at least .5 cfm at 5-8 psi (the Paasche® Airbrush Compressor ( #37072 ) works great). You can even use a portable air tank with regulator.
  • A clean, safe, well-lit, well-ventilated work area (see safety guidelines ).
  • An activated charcoal respirator like our Professional Respirator ( #34029 ).
  • A pair of goggles ( #43090 ) to provide eye protection during coating and gun cleaning operations.

Work Area Setup

Ventilation Set up work area to allow for good ventilation. Oven You must have access to an electric oven or toaster oven other than the one used for food, as mildly toxic fumes are liberated from the powder while curing. Used ovens can be found in appliance centers, news papers, and yard sales. The oven must be in good working condition. Containing the powder Put down a clean tarp to collect powder dust for easy cleanup. Do not use a vacuum unless it is equipped with an explosion-proof motor. Electrical Supply Use a convenient grounded 110-120VAC outlet or heavy-duty extension cord to plug in the 6′ power cord. NOTE: Unit must be grounded to work properly and safely! Air Supply Need convenient access to an air line from a portable regulated air tank or air compressor capable of being regulated down to less than 10 psi. The gun uses less than .5 cfm at 8 psi, so a modest compressor will suffice. Storage Store unit and powder in a clean, dry area no hotter than 80° F.

Preparing the Part

Before You Start
    • Remove all items from the box. Compare with list of contents to make sure unit is complete.
Description of parts and function:
  Grease and Oil Removal Metal part must be free of any oil, dirt, or other contaminants before powder coating. Clean with Metal Wash ( #10120 ) or spray down with PRE Painting Prep ( #10041Z ). Wipe and blow dry the part. Masking the Part Once the part is thoroughly dry the powder can be applied. Handle the cleaned part with vinyl gloves to avoid contamination. Finger prints can effect adhesion! Determine how the part should be positioned in the oven before the coating process. Use the High Temperature Plugs ( #10078 ) or High Temperature Tape ( #10027 ) to protect critical tolerance areas. Since the powder will coat around corners be sure to mask all appropriate areas.

Preparing for Curing

Hanging or Placing the Part for Coating Bend wire hooks to hold the part during powder application and curing. Our .041 Stainless Steel Safety Wire ( #43045 ) works well for this application. Don’t use a coated wire as debris from the wire coating may fall on the part during the curing process. High Temperature plugs ( #10078 ) can often be used to support the parts above the trays, and plug bolt holes. Preheating the Oven Before powder coating the part – preheat the oven to the cure temperature indicated on the powder container (usually 400°F, 204°C). Check temperature with an oven thermometer or the Non-Contact Infrared Thermometer ( #43175 ). Use of Oven Tray Make sure the oven is clean. Use aluminum foil to keep racks and oven interior clean. Practice moving part from area where powder will be applied to inside the oven to avoid damaging the uncured powder you will soon apply. Coating Porous Materials In some cases, contaminants in porous materials will cause pits in the powder. Porous cast iron, die cast, cast aluminum and magnesium parts trap contaminants, that, when heated will out gas and cause porosity problems when the powder is cured. See preheating, below. Preheating the Part To prevent porosity from occurring, preheat the part. The time that a part needs to be preheated varies with size. Preheat to between 200°F and 400°F. Use PRE Painting Prep to remove the newly exposed contaminants. Wipe the part repeatedly until no further dirt comes off on a clean white rag. Let the part cool to room temperature before applying the powder. Containing Powder Overspray Put down a clean plastic tarp in the area you will be applying powder to ease cleanup.

Preparing to Powder Coat

Filling the gun with powder Use a clean sheet of paper or a funnel to pour the powder into the cup. Fill the cup no more than 1″ or 2″ with your color of choice. See photo . Tip: Handle powder as if you were handling liquid paint. Use clean disposable gloves when handling powder to avoid contamination. Keep powder containers tightly closed. Attaching the Air Supply to the Gun Connect a low pressure air line to the gun. The gun requires .5 or more cfm at 5 – 10 psi, with 8 psi being ideal. If you do not have an air compressor, a portable air tank with regulator can be used. The air must be moisture and oil free. Caution: Never exceed the 10 psi! Connecting the Ground Clip Connect the ground clip to the part you are powder coating. Grounding the part provides a path for static charges to dissipate. Touch gun emitter to ground clip after each time activator switch is released! See photo . Checking the Gun Spray Pattern Note: Before using the gun make sure that the 3 static tubes are in place and deflector installed. Pull the gun trigger to check the pattern. Unlike regular paint guns, the HotCoat® gun creates a fog of charged particles. See photo .

Application of Powder

Caution: Before plugging in the unit, make sure that all the cords are uncoiled and free to move (do not depress the activation switch). Hold the gun at various positions and angles to get the best application of powder over the entire part. Application of Powder Plug the power supply into a grounded outlet. Maintain approximately 8 inches between the gun tip and part being coated. Depress the activation switch while triggering the gun. Depressing the activation switch energizes the gun, charging the powder. Releasing the switch turns the power off. Once the activation switch has been released, a slight charge will remain in the gun until the emitter is touched to the ground clip. Be sure to touch the emitter to the ground clamp before touching the emitter. Move the gun in slightly different angles to ensure that all areas of the part are covered. Be sure to coat deeper crevices and inside corners first to prevent uneven coating. The coated surface will have a dull opaque coating of powder. Make sure all areas of the part are coated evenly. Powder can sometimes be difficult to apply in deep recessed areas or into corners. Try repositioning the part to allow gravity to help assure coverage in corners and reposition the the gun as shown above. Practice on some scrap pieces of metal to obtain a uniform coating. Before Touching or Cleaning the Emitter The gun becomes less efficient as powder builds up on the gun emitter. To remove powder buildup from the emitter, release the activation switch, and momentarily touch the emitter to the ground clamp (the resulting spark indicates the system is now discharged). Wipe off the electrode with a dry cloth. When you are finished applying the powder to the part, release the activation switch, touch the emitter to the ground clip, set the gun down and unplug the power unit.

Curing the Powder

Loading Part into the Oven Make sure the path to the oven is clear and oven is up to the required cure temperature. Now, using a pair of pliers (if necessary) and wearing leather faced Buffing Gloves ( #31010 ), place the part in the oven. Be sure not to bump or disturb the powder. See photo. Curing the Powder Finish Cure the part in the oven for the time indicated on the powder container (usually 20 minutes). Note: Larger parts may require additional time for a complete cure. During the cure process the powder gradually melts, changing from a dull flat finish to a smooth gloss finish. When coating parts such as intake manifolds or wheels keep checking every 5 minutes until you see the powder start to gloss over. When the entire part completely glosses over, cure for an additional 20 minutes. If after 35 minutes the coating hasn’t flowed out see the trouble shooting section . Make sure you have an accurate timing system. If parts are left in the oven too long, the coating may become rough and will need to be removed and redone. Safety Note: Always cure powder in a well-ventilated area and wear an activated charcoal respirator while curing to protect against unpleasant fumes. Once the curing is complete, allow the part to cool down gradually by turning the oven off and opening the door slightly. Note: Cooling too quickly may dull the sheen of some finishes. Tip: If after curing you notice some areas have been missed, you can recoat the entire part or use our 1-Shot Lettering enamels for touch up. If necessary to improve gloss, or level slight orange peel, cured powder can be wet sanded with 400 grit wet or dry paper and compounded to a high luster with conventional paint polishes or buffed using White Rouge on a Loose Section buffing wheel . Keep the part moving during buffing because localized heat build up will cause melting and leave a rough surface.

Clean Up

Cleaning the Gun When you are finished using a particular color, you must clean the gun before using another color. To clean the unit, unplug it so no voltage is in the unit. To discharge the gun, touch the emitter to the ground clip. Disconnect the air supply. To avoid moisture pickup, DO NOT store powder in the gun-mounted cup! Now the gun is safe to handle. Unscrew the cup, pour the remaining powder back into the can. Using compressed air, clean the discharge and pick up tubes, cup, static tubes, and deflector thoroughly with no more than 30 psi compressed air. (TIP: use clean disposable gloves during all gun cleaning operations). With your disposable nitrile or vinyl gloves on, gently twist off the deflector and remove the three static tubes. Using your blow gun thoroughly clean the inside and outside of all the static tubes and deflector. You may also find it convenient to use the Engine Cleaning Brush Set ( #46035 ). It is important to keep your dust mask on while cleaning the gun. It is NOT RECOMMENDED to recycle the powder that landed on the floor. Only pure, uncontaminated powder is to be returned to the storage can. Powder collected on a clean tarp or from a clean box can be recycled if it is strained through a paint strainer. Keep the powder can tightly closed to prevent moisture absorption. Mixing with other powders and dust can cause pits in the surface. Do not use solvents when cleaning your powder coating system. The gun and components are to be cleaned with compressed air only. To make your clean up even easier, use our 14 Pc. Compressor Accessory Kit ( #43223 ). Using the extensions in this set allow you to blow the powder right out of the gun. Direct air into the nozzle and the pick up tube to make sure no powder remains. The only other cleaning necessary is to clean up the powder on the floor or workspace. WARNING: Powder dust in heavy concentrations is potentially flammable! Due to a possible explosion risk never use an electric vacuum, shop vac, or wet/dry vac to clean up powder!

Reusing the Powder

Powder swept from a clean tarp can be poured through a strainer for reuse. You can only reuse it when you are positive that you had a clean drop cloth and the powder is not contaminated by any foreign matter. Contaminated powder may cause pits and orange peel. Contaminated powder can be safely disposed of in the trash. Caution: Before reconnecting your powder gun be sure to change the air pressure from 30 psi back to 8 psi ! The cup and lid assemblies are designed for no more than 10 psi. Replace your moisture filter regularly, as moisture will build up even when the gun is not in use.

Putting Parts Back in Service

Powder coating is an extremely durable flexible coating. However care needs to be exercised when bolting powder coated components in place. To avoid chipping use washers under nut and bolt heads. Tips on care of powder coated surfaces Powder coated surfaces easily shed dirt. Wash with a dish soap and water solution. Automotive (nonabrasive paint polish) may be used to remove water spotting and enhance the gloss.

Removing Cured Powder

The coating can be removed using Eastwood’s Aircraft and Automotive Paint Remover ( #34069Z ). Remember powder coatings are more solvent resistant than other coatings and may require more time than paint to remove. To speed results, cover the part with a heavy coating of remover and cover the remover with a plastic bag to prevent evaporation.

Warnings

Safety: Read and understand all instructions and precautions before proceeding. This unit uses high voltage, and uses powder which may become flammable under certain circumstances. Eastwood shall not be held liable for consequences due to deliberate or unintentional misuse of this product. DANGER: UNUSUAL FLAMMABILITY HAZARD! Powder coating dust, when confined and suspended in air, poses a definite fire and explosion hazard if ignited. Good housekeeping, adequate ventilation, dust control and isolation from potential ignition sources is required! Sweep up unused powder from the floor. Do Not Vacuum unless the vacuum is equipped with an explosion proof motor! Never smoke while powder coating. Do not apply powder coat near any source of ignition, e.g. open flames, sparks, etc. Do not use a gas oven for curing powder coatings: use only an electric oven that is in good repair. Use the same precautions that you would for liquid solvent based coatings. DANGER: HIGH VOLTAGE! READ AND UNDERSTAND ALL DIRECTIONS BEFORE PROCEEDING! The power supply is a sealed unit and contains no user serviceable parts! Contact with the emitter will result in an unpleasant shock! To eliminate the shock hazard, touch the emitter to the ground clip after each use. (If you have a medical condition or pacemaker check with your doctor before using.)

Electrical Safety Tips

Safety Do’s
  • Make sure you, your work area, and your equipment are dry.
  • If you are using an extension cord, make sure it is in sound condition with no damage or frays, and of the correct wire gauge.
Safety Dont’s
  • Never bypass the ground plug. Grounding is important for operation of the unit and prevents shock.
  • Do not touch the emitter until after the activation switch is released and the emitter has been touched to the ground clip. Once you are spraying the part with the powder, avoid touching the gun to the part or other grounded objects.
  • Do not step on, kink, or pull the wires. Before using the gun inspect the condition of all wires.
  • Do not use a vacuum unless it is equipped with an explosion proof motor.
  • Do not touch or hold the part while coating.
Personal Safety Tips:
  • The powder is considered a nuisance dust and and consists primarily of pulverized plastic (polyurethane or polyester).
  • Wear a Dust Mask to protect your lungs when handling, applying powder and clean up!
  • Oven cure powder coat in an electric oven only . Use an oven other than the one used for food, as mildly toxic fumes are given off by the powder residue during the curing process and may remain in the oven.
  • Oven should be operated in a well ventilated shop or open area, not inside a house or enclosed living space.
  • Always work in a well-ventilated area! Wear an activated charcoal respirator when oven curing the powder.

Environmental Concerns

Powder can be safely disposed of with the household trash. Powder coating minimizes the EPA’s concerns over VOC (Volatile Organic Compounds) and solvents because there are no solvents used when applying powder, or cleanup.

Troubleshooting

Pitted Finish Make sure part is completely cleaned of all contaminants with Metal Wash ( #10120 ) or PRE Painting Prep ( #10041Z ). Coating Porous Materials In some cases, contaminants in porous materials will cause pits in the powder. If this occurs remove the powder coat with Eastwood’s Paint Remover, rinse with water, and spray with PRE Painting Prep. Porous cast iron, die cast, cast aluminum, and magnesium parts trap contaminants that, when heated, will outgas and cause porosity problems when the powder is cured. To avoid this follow preheating instructions below. Preheating To prevent porosity from occurring, preheat the part. The time that a part needs to be preheated varies with size. Preheat to between 200°F and 400°F. Use PRE Painting Prep to remove the newly exposed contaminants. Wipe the part repeatedly until no further contaminants come off on a clean white rag. Let the part cool to room temperature before applying the powder. Orange Peel “Orange Peel” is a rough surface resembles the surface condition that texture of an orange. A certain amount of orange peel is unavoidable especially with polyester based powders. An orange peel condition can often be removed by sanding the part with 400 grit sand paper (wet or dry) and finishing as you would conventional liquid finishes. If you want to buff by hand use Autosol polish. Another cause of rough finish condition is excessive powder build up. You will know if powder build up occurs because the powder will start to stand on its end like hair. If this happens, stop applying powder and with light air pressure blow off some of the powder. If powder does not apply evenly due to moisture build up, replace moisture trap on gun and use fresh powder. Cured powder can be finished in the same manner as liquid paint. Poor Spray Pattern If the gun does not spray, the air pressure could be too low. Moisture could be clogging the Disposable Filter ( #34066 ). Replace if necessary. The level of powder in the cup should be at least one inch deep from the bottom of the cup to flow efficiently through the gun.   Required Items  |  Work Area Setup  |  Preparing the Part  |  Curing Prep   |  Preparing to Powder Coat Application of Powder  |  Curing the Powder  |  Clean-Up  |  Reusing the Powder  |  Removing Cured Powder Warnings & Safety Tips  |  Environmental Concerns  |  Troubleshooting  |  Powder Coating 101