Silicone Caps

To ensure a tight, leak-proof seal, measure the outer diameter (OD) of the stud or shaft you need to mask. Select a silicone cap with an inner diameter (ID) that is 2–5% smaller than the stud's OD to create a necessary interference fit. Additionally, choose a cap length that is just long enough to cover the required area; excessive length can trap air, which may expand during oven curing and cause the cap to pop off.

Our silicone masking caps are made from high-grade silicone rubber rated for continuous operating temperatures up to 250°C (482°F). This thermal stability ensures they will not melt, deform, or transfer silicone oils onto your parts during high-temperature processes like powder coating or e-coating.

Powder bridging occurs when coating accumulates at the transition point between the cap and the part, leading to jagged edges when the cap is removed. To prevent this, use flanged silicone caps. The built-in skirt or flange acts as a barrier, tapering the powder away from the critical edge and ensuring a clean, sharp masking line upon removal.

Yes, silicone caps are designed for multiple reuse cycles, significantly reducing consumable costs. In powder coating applications, the cured powder typically flakes off easily when the flexible cap is squeezed or rolled. For cleaning, mechanical removal (flexing or tumbling) is recommended. Avoid soaking the caps in aggressive chemical strippers, as this will degrade the silicone and shorten their lifespan.

Yes. If our standard cap range does not match your stud diameter, shaft geometry, or application requirements, we can manufacture custom moulded silicone caps to your exact specifications. Custom caps are particularly valuable for non-standard geometries, flanged designs, or high-volume production lines where a perfect fit eliminates rework and improves throughput. Quotations are typically provided within 24 hours, and samples are available within 2 to 3 weeks. Contact us to discuss your requirements.