It’s not popular, but I use silicone in all of my brushes. It allows me to swap out later if I need to, but you would be amazed how difficult it is to do once it is cured. It doesn’t destroy the brush, but it takes more effort than you can imagine
I used silicone on a series of brushes with coins that I made for a group buy last year and no complaints yet but I did wonder if there wasa "usual" way - it seems not!. I will stick [hahaha] with silicone!!!
He's not installing the knot, he's attaching a metal coin to a metal brush. I second the two stage epoxy advice. You can buy them in a dual chambered syringe at any Wal*Mart or equivalent.
Do not use gorilla glue on a brush handle. Ever. The whole "get it wet to activate it, and the expansion as it dries, it's just not recommended. If it doesn't split the handle (easy to do on vintage handles), it will bubble up into the knot. If you watch it like a hawk for the first 10 minutes or so, you can wipe away excess as it bubbles up. I've used it, once. It does work, but there are much better options out there. Edit: you could use it to attach the coin, though.
I also use two part epoxy. At the moment I'm using J-B Weld, as it's very strong. Plus I found a great deal on Amazon for their large tubes.
