How to remove powder coating?

How to remove powder coating?
Powder coating can be removed by sandblasting the surface of the coated part with an abrasive media, using a chemical stripper, or by prolonged exposure to high temperatures (usually above 750°F) that degrade the surface quality

Common methods for stripping coated parts
For most powder coaters, stripping the surface of coated parts can be a real pain in the ass. There are several ways to remove coatings from parts before recoating with powder, but we will focus on the two most popular stripping methods: mechanical stripping using sandblasting and chemical stripping using a dip tank.

mechanical peeling
Mechanical stripping usually involves sanding, polishing or sandblasting to remove the old coating.

Sanding or polishing is very simple, but it is often the most laborious method of removing previous paint. This is a valuable technique for repainting powder-coated parts. Unfortunately, restoring parts to bare metal requires a lot of care, effort, and time.

powder coating sandblasting

Sandblasting is a better option for stripping parts when other methods are unavailable or not permitted. Choosing the right grinding media is key. Most sandblasting operations are performed to clean and prepare the metal stock for coating. It is not uncommon for sandblasting systems to be used to remove scale and rust as well as provide some texture to the surface of parts that require coating.

Stripping paint or powder coating off a part is a similar but slightly different process. When cleaning raw metal parts, you can use less abrasive media like sand or glass to help maintain the part's surface detail and prevent accidental damage. Stripping parts often requires more corrosive media such as steel shot, garnet, or aluminum oxide.

All of these grinding media have different particle sizes, leaving different abrasive grain profiles. Keep in mind that if a deep mil profile is left, more powder will be needed to cover up the rough texture left by the powerful sandblasting. If you choose a finer grit, you will spend more time sandblasting the part, but you can preserve fine surface details, such as decorative scrolling. It's really a balancing act of figuring out how much labor you want to put in versus how smooth you want the final look of the coated part to be. On the one hand, more spray time obviously means your costs will increase. On the other hand, using a larger particle size will require you to apply more powder to cover the part, and you may have to deal with a more noticeable "orange peel" appearance on the surface of the finished part.

chemical peel
For those coaters who refinish a large number of parts on a daily or weekly basis, chemical stripping may be a viable option, especially if the parts are not particularly large. If your customer performs extensive paint stripping work, a dedicated paint stripping tank can remove previously applied coatings without damaging the contours of the part being refinished.