Can Rust Ruin Powder Coating if It’s Not Cleaned Off First?

Powder coating is a highly durable method of finishing a material or part, and the coating will be capable of holding up to even the most extreme environments. However, there are certain limitations associated with the coating, one of which is that the coating will not set in well if there is debris on the material before coating.

For example, can rust ruin your powder coating in Washington? Rust is a particularly problematic issue you may have to deal with on a metal substrate. We frequently have customers ask whether simply powder coating over rust is a feasible option, rather than having to go through the rust removal process. Here’s an overview of what you should know about rust and powder coating if you are going to be coating metal.

Rust and powder coating

The rust removal process can be difficult, but it’s necessary if you are planning to powder coat a piece. Rusty metal will be very difficult to clean, and if the metal part is not perfectly clean before powder coating, you will have a much harder time getting it to stick.

That’s not to say it will be impossible for you to get the powder to stick—powder coating gets applied with a static charge, so it is at least possible to get powder to stick and cure on top of rusty metal. However, the chances of this happening are much lower than if you’re working with clean metal, and even if you succeed, the chances of the finish actually lasting will also be significantly lower.

Over time, powder coating on top of rusty metal is more likely to result in outgassing, bubbles or surface imperfections that result in a poor finish. The rust will also continue growing underneath the powder coating over time. Because the powder coated finish is only going to be as strong as the surface underneath it, the growth and flaky nature of the rust could result in the powder falling off.

So, while there is a possibility you may be able to get a powder coat to stick on top of rusty metal, it will be harder to accomplish, and you’re more likely to have long-term issues with the integrity of the finish. This is why it’s so important to properly clean the metal before you begin the powder coating process, which will include removing any rust that’s present on the metal.

With regard to the best methods to use to remove rust, it really depends on the extent of the rust, the kind of metal you’re working with and the size of the part. In some cases, the media blasting process you use to clean the metal material before powder coating might knock all the rust loose. In other cases, you might need to rely on chemical rust removal products to get rid of more stubborn rust spots on your metal surfaces.

For more information about powder coating over rust in Washington, we encourage you to contact Powder Vision Inc. today.