The Art of Stripping Coated Parts: A Guide for Powder Coaters

As someone who’s been in the powder coating industry for a decade, one of the recurring challenges I’ve seen is stripping the finish off coated parts. Every seasoned powder coater knows the pain of removing an old coating to reapply a fresh layer. Today, let’s delve into the two primary methods of stripping: Mechanical Stripping and Chemical Stripping.

Need more reference, check out this blog post.

Mechanical Stripping

Mechanical stripping, while effective, requires a hands-on approach. Here’s what you need to know:

1. Sanding/Buffing: This technique, though straightforward, is labor-intensive. Taking it from experience, having one of my employees, Dave, spend hours sanding down a part to its bare metal, I realized that while this method is invaluable for certain projects, it isn’t the most time-efficient.
2. Blasting: At our Californian workshop, we often resort to blasting, especially when we’re restricted from using other methods. The choice of abrasive media is crucial. For example, when we worked on a vintage car restoration, we had to be careful with our abrasive choice to ensure the car’s intricate details remained intact. While less aggressive media like sand preserves the part’s details, stripping requires a more aggressive approach using steel shot or garnet. It’s a delicate balance between the effort you’re willing to put in and the final appearance you aim for. Remember, a rougher texture left by aggressive blasting means more powder to achieve a smooth finish.

Chemical Stripping

For workshops handling bulk refinishing tasks, chemical stripping comes as a boon. Here’s what I’ve learned:

1. Dedicated Strip Tanks: In our shop, we noticed a significant increase in stripping jobs, prompting us to consider dedicated strip tanks. These tanks ensure the part’s profile remains undamaged, which is crucial for parts with intricate details.
2. Using B17: This solvent, commonly found in many workshops (including ours), is a lifesaver for occasional stripping jobs. However, a word of caution: it’s aggressive. We had an incident where one of our newer employees, Jake, didn’t take the necessary precautions, resulting in minor chemical burns. Safety first! Always use protective equipment like face shields, goggles, rubber gloves, and respirators. Rinsing the parts thoroughly after the stripping process is equally crucial to neutralize the solvent’s effect.
3. Greensolv Strip Tanks: For regular stripping tasks, devices like Greensolv’s strip tanks have been game-changers. They simplify the stripping process, recondition the solvent, and filter out the residue, ensuring a cleaner and more efficient process.

A Word of Caution

Whether you opt for mechanical or chemical stripping, remember that once the parts are stripped down to bare metal, they’re vulnerable to rust. In our shop, we’ve had instances where stripped parts left untreated for a while showed signs of flash rust. It’s imperative to seal or treat these parts immediately before coating.

Final Thoughts

Stripping is an art as much as it is a science. Each part, each project, demands its unique approach. By understanding the nuances of mechanical and chemical stripping and learning from our experiences, we can ensure a smooth and efficient process, delivering impeccable results every time.