Masking Threaded Nuts and Bosses

Question:

What can I use to prevent paint from getting into the threads of nuts and bosses? We have tried a variety of plugs, including a special design, without satisfying our customer. Is there a coating (Teflon) that can be used? Our cure oven typically runs at 410F and the product is in it for 30 min. J.N.

Answer:

I am not exactly sure what your customer's complaint is. Most times silicone plugs and caps have been very effective at masking threaded nuts and bores. Obviously, you must select the right plug for a given size hole. Tapered plugs are easier to use and quickly release when they are removed, but they can leave areas (at the tapered end) that are not well protected. There are many companies that offer masking devices listed in the Suppliers database at www.pfonline.com or in the 2001 Products Finishing Directory and Technology Guide. I suggest selecting a company with a robust product line to find a masking device to suit your needs.