Powder Coating Adhesion Trouble Shooting
Posted: March 22, 2019 By: MattM
What to do when Powder Won’t Stick to a Part
Not much more can be more frustrating than having powder coating adhesion issues part way into your project. At this point you’ve probably invested a lot of time cleaning the part for powder and preparing your powder coating gun and supplies to shoot powder. We decided to give you a quick trouble shooting guide for adhesion issue when powder coating.
- Contaminants on the Surface- Even though you’ve cleaned your part well you may still have issues with powder sticking to the surface because of some hidden oils, dirt, or grease. We suggest pre-baking a part to bake out any hidden oils or grease and wiping it down again with PRE Paint Prep after it cools. For best results you should also media blast the part to clean it and give a texture for the powder to bite into. If your part isn’t clean enough the charged powder may not be able to stick to the area that has a film of oil or grease on it.
- Improper Grounding on the Part- If you’re attaching your ground cable to the part itself it needs to have the best connection it can or your powder won’t stick. That ground connection completes the circuit for the electrostatic charge and is what helps attract the powder to the part. Check your ground clamp to make sure the wire isn’t frayed or broken and that the clamp isn’t coated in old powder. You may also want to make the area on the part is clean and free of paint or other coatings. This problem can occur when applying multiple coats as you may lose a place to attach your ground to. Sometimes you need to get creative with stainless wire to wrap in an area the stay bare to assure a proper ground. We make it a habit to clean out ground clamp of old powder each time when we’re doing using the powder coat gun.
- Improper Booth Grounding- If you’re a serious enthusiast or a professional you probably have a dedicated paint booth for applying powder to your parts and you will want to properly ground the booth itself. This allows you to simply hang or lay parts in the metal booth and they will be grounded without attaching the clamp directly to the part. You can ground a booth by driving a grounding stake deep into the ground and attaching a heavy wire from the stake to the booth for the best dedicated ground. If the stake or jumper wire get loose or broken you may loose your ground connection. You can test if your booth has a good ground by holding the gun a short distance from the side and hitting the powder gun trigger (with the ground clamp on the booth) and you should see the arc jump from the gun tip to the booth. If you don’t see this then you may have a grounding issue. Over time you may also get a buildup of old powder that can cause a bad ground from the booth to the part itself. Always make a habit to clean the booth of old paint and powder before starting a new project.
- Powder Coating Gun Failure- If the power source on the gun fails you may have a similar issue that could make you think it is a ground issue. You can quickly check this by pointing the tip at the grounding clamp and pressing the trigger to see if the arc jumps to the ground clamp. If there’s no spark you may have a bad power source in your gun and should contact the manufacturer.
Hopefully this tips help you diagnose your powder adhesion issues. If you need to replace your powder gun or get additional powder coating supplies you can visit our site HERE.