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Powder Coating Masking Problem

In a product that I am applying powder coating there is a hole that should be masked previous to powder application. After the powder application the curing process is based on infrared oven. I faced with 2 situations. 1) On the interface between de plug and de product hole, after curing, the powder coating forms a fragile burr that can drop into the product when I remove the plug and I need to avoid it due to contamination issues. 2) Sometimes the plug is ejected out during the curing process due to increased internal pressure into the product. Can you help me in solve those problems?

Alex Condotta
Manufacturing Process Development - Brazil
January 5, 2010

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Hi there Alex,

It sounds like there are (at least) two possible solutions to the problem you're having.

The first one is simple, though it may not be practical for you: If you can remove the plug after the powder is applied, but before it is cured in the infrared oven, this will keep the plug from "blowing out" due to internal temperatures or powder curing on the part and mask causing a burr. However, depending on how your line is set up, this may not be practical for you.

The second is to have a custom plug made. I don't know the configuration of your part, but if the hole you are masking is large enough then a small air-bleed "valve" can likely be built into a masking part to release heated air while curing, and the part itself can be designed to minimize / eliminate the burr. There are many good masking companies in the U.S. that can help you with a custom plug design: Viadon, Shercon, Echo, EPSI, Argon are just some of the companies that have the expertise to make a good custom molded part for you. My apologies - I don't know if there are any in Brazil, but there may be.

Hope that helps.

David Fuller
- Monee, Illinois
January 11, 2010