A good ground to your parts is essential for good powder coating results. A dedicated ground rod is recommended.
This rod can be used to ground both the parts and the booth. Often we see a hook or bar attached to the booth and the parts hung inside the booth for coating. As this relays on the continuity and cleanliness of the hooks to make the ground thru the booth, it is also recommended to also have a ground cable to hook directly to the part.
The better your grounding, the better the powder will stick and the fewer problems you’ll have. Having a good ground is essential, especially when applying multiple coats. It can be as crucial as any other part of your powder coating process. Here are few things to check so you are getting the best ground and not wasting powder, while having a high-quality finish and staying safe. From our training manual:
Grounding Rod – Using the copper rod in the ground 6-10 feet is the best start. If the ground is sandy or in dry soil, add water to the area around the rod and allow it to soak.
Rack and Hooks – when using a rack and hooks make sure the area where you connect the clamp is cleaned before it goes into the curing oven. Powder will accumulate in expose areas that are not being use to hang part. An easy solution to prevent the paint from curing in these areas is to use high temp tape. Keeping the hooks clean so they are well grounded is one of the best ways to guarantee the powder sticking to the part at a higher rate. It may feel like too much time is spent on cleaning the hooks but it will be more affordable when you have a higher transfer of powder to your parts which will lead to less powder wasted.
Parts – making sure your parts are grounded can be more difficult with larger parts. When you have large parts, try to clamp directly to them. Powder coat the area you can and then move the clamp and finish the area where the clamp was.
Issues that result from poor grounding include issues with back ionization, an inability to successfully apply two coats of powder, getting shocked regularly, excessive powder waste, poor powder buildup, low or no coverage in faraday cage areas, and a multitude of similar problems.