Product View | Watersports Warehouse - watspo.com We have improved the water sealing capabilities of our rivet by replacing the small rubber washer with a much larger countersunk foam membrane. This is the industry standard structural tri-locking riv We have improved the water sealing capabilities of our rivet by replacing the small rubber washer with a much larger countersunk foam membrane. This is the industry standard structural tri-locking rivet. Black anodized finish. Designed with a grip thickness range of .375" to .562". Roto-molded kayaks are about .200" thick, so the part you are riveting must be between .175" and …