Many different types of caps and plugs are used to cover threaded
studs, bosses, and holes. The cost is reasonable and they can be reused or left in place. They usually seal the masked area very effectively and they are less likely to "bridge" to the coating and create a rough parting line than a metal mask.
There are many standard sizes available and they can also be custom made to fit a certain product.
Specific sizes can be purchased at a reasonable cost in quantity. Sample kits with a variety of different plugs can be purchased to test different sizes and see what works best in a given situation. It is a good idea to have an assortment of sizes and styles around for product testing.
Caps and plugs are made of PVC, neoprene, silicone and other thermoplastic materials. The correct type for a specific masking job depends on the price and cure process.
High temperature materials are required for powder coating operations. For example, silicone plugs may be capable of withstanding temperatures of 600 °F (315 °C).
Neoprene is usually only good to temperatures of 275 °F to 350 °F
(135 °C to 177 °C).
Select a material that will meet all of the demands
of the process for a fair price.
June 14, 2012