A router guide collar is a useful accessory that threads onto a router base and guides the router along a pattern or template. The one safety concern with guide collars is that they can loosen and possibly fall off, causing damage to your work or maybe an injury. You can make sure that your guide collar won't loosen by using PTFE ahead tape (also called teflon tape) to wrap around the treads. You can find this special tape in the plumbing section of most hardware stores. Subscribe to this channe