The authoritative public forum
  for Metal Finishing since 1989
-----

Powder Coating Complicated Piece, How To?

Powder Coating- we have a part we need to powder coat with a fairly complicated design around corners and with fairly tight tolerances.. This is a new process and I'm just fishing for some ideas. I'm new to powder coating so simple ideas are good too. Is masking an option? and if so.. with what? Thank You.

Tom Greifenkamp
- Cincinnati, Ohio USA
2001

---

It is probably important to know exactly what you are trying to powdercoat in order to offer the best advice.

Masking is possible with powdercoat. You can try taping off areas, or capping/plugging the ends so that no paint enters the part. If tolerances are tight and you must hold critical dimensions, you can try e-coating the part instead. It offers an equivalent performance without the thickness.

Rachel
- Orion, MI USA
2001

Ed. note: Since 1989 this forum has enjoyed the camaraderie & warm aloha which real names & locations afford. If you're not into that spirit, those who do post with their real name may be less likely to engage with you.

Sorry for the lack of information-

If you could imagine having to coat a pair of pliers. Everything has to be coated except where the two halves come together and pivot and the flat section that actually does the grasping. The material must insulate the base metal (SS). I'm not too familiar with e-coating but the nature of it sounds as if it won't insulate. If I'm wrong, please fill me in with some details.

Sincerely,

Tom Greifenkamp
- Cincinnati, Ohio USA
2001

---

2001

You should work with your supplier to see if what you want to do is possible. They should have experience to share and hopefully know the limits of their capabilities. Also, I agree with the previous answer of looking into electrocoat (e-coat).

Most e-coaters and powdercoaters can mask areas, and it is not uncommon. However, masking is put on and taken off by hand. Handling each part twice by hand adds a lot of cost to your process. You will also have to experiment with what type of masking is most effective. You can use plugs, tape [green powder coating tape] (affil link), caps, and more. If this is a complicated part, you should also figure out proper racking. If you go to e-coat, you have to worry about contact points and getting an even current density across the part to achieve an even, tightly controlled thickness across your part.

Tim Neveau
Rochester Hills, Michigan

If your part doesn't have to be pretty you should check into autodeposition, then post-machining the areas that need to be clear.

Autodep is made exclusively by my competition, Henkel, but when it's right for the application it's unbeatable. Post machining may even be cheaper than masking depending on the part.

Autodep is a different animal from e-coat, e-mail me if you want a contact on a shop that can do it.

Jeff Watson
- Pearland, Texas
2001

---

If you are doing the coating yourself electrostatically, you may experience the same current density problems that platers have. You might want to try heating the part to the powder cure temperature, then dropping it into the powder. I have not tried this, but understand that it works quite well. I'd guess that you would also want to oven cure the part to ensure total cure. For those of you that have not tried powder coating, it is terrific. I'll never (wet) paint again.

Best Regards,

C. Barry Ward
- Atlanta, GA, USA
2003