Inventing the BAKEWELL Silicone Rubber Powder Coating Plug
It may be a cliché that need is the mother of invention but, in the case of the Bakewell Silicone Rubber Powder Coating Plug, it’s certainly true. As powder coating took over from wet paint spraying in the early 80s, a new need was identified. AFAC, or Applied Fastenings and Components as the company was then known, devised the perfect solution – The Bakewell SIlicone Rubber Powder Coating Plug—and it’s still selling strongly to this day!
Back then, the company’s business mainstay was supplying fasteners to sheet metal workers. If a customer required a female thread, either a weld nut, rivet bush or self-clinching nut would be supplied. Once assembled, these solutions provided a far stronger captive thread than simply tapping a hole through the sheet metal.
Happy clients all round? Well, no! There was still an issue. Sheet metal components tend to need protection from oxidization. In other words, they are painted, plated or given an electro-static powder coating. The problem with this is that exposed threads can become contaminated by the coating process, leaving them unfit for purpose when it comes to the final assembly.
AFAC had already solved this problem with regard to male threaded studs, so it was natural we should start casting around for a way of protecting the female threads. The existing solution of using PVC tapered plugs was fine for wet painting—but they couldn’t take the heat generated during powder coating. Diligent research suggested there was a material that would be just perfect for the job—silicone rubber. Able to withstand temperatures of up to 315°C while remaining flexible, it made the perfect solution for thread masking.
Careful thought went into the design of the new plug. Tapered in shape, it had a cylindrical head for easy handling. It was trialled in a range of sizes to ensure it sealed the thread, while leaving approximately one third of the plug out of the hole. This allowed electro-static attraction to draw the powder under the cylindrical head to cover the component right to the very edge of the hole. With generous help from a local powder coater, the new plug was tested and declared a success!
The Bakewell Silicone Rubber powder coating Plug has now been in production for over 30 years, in a range of colour coded sizes, and it continues to be an invaluable masking tool for all powder-coating operations. It’s the original hole-masking solution—devised and designed by AFAC!
