Loon’s UV Knot Sense is a great thing to have in you vest. Simply coat your knots with a thin layer and let the sun do the rest. It will create a coat increasing the strength of all your knots. Also works great to repair flies when you’re on the river. On sunny days it will cure in a matter of a few seconds, cloudy days a little longer. For indoor use, use Loon’s UV mini Lamp.