I found a two-piece wood paddle with brass ferrules that washed up on a beach and after repairing it, I have been using it as my primary paddle. However the two halves sometimes twist as I'm paddling and I have to occasionally stop and re-align them. Store bought two piece kayak paddles have these spring loaded thingamajigs that allow the two halves to be locked securely together. Anyone know what they're called and where I could find some?