Get the knot and familiarize yourself with how the knot fits in the hole. It will usually only fit one way.
Once you have that figured out simply get your glue and apply it to the picket wall of the knot hole AND to the outer edge of the knot itself.
Install the knot back in the hole and position for best fit.
Wipe off any excess or drips and let it dry! That's it!!
Here is a video to show you how....
If you have any questions, please contact us and we will be happy to help you!