Closing clinch knots?

I have trouble completely closing a clinch knot and wonder if there is something wrong with the knot.

Q. I have trouble completely closing a clinch knot and wonder if there is something wrong with the knot. --Bill Kerns, San Diego, CA

Almost all knots are a form or a combination of a clinch, nail or overhand knot. For example, a blood knot is simply two clinch knots, while a Duncan loop and a uni-knot are just a form of clinch knot. When a clinch knot is closed, the tag end usually loops away from the main line. If the tag end is gently pulled until it lies alongside the spirals or coils previously made and then lubricated, the knot will close easily.

-Lefty