: Don't wait for the thickened epoxy to harden. Lay it out all at
: once,

Yes, do it all at once. I re-checked Vaclav's instructions and he does not mention any delay between laying in the thickened epoxy around the sacrificial gasket and laying on the glass or carbon fiber layers. I followed his online instructions closely and had it work beautifully the first time. I mixed in some graphite powder in the thickened epoxy to get a nice deep black in the ring. Just be sure to lay in the thickened epoxy carefully to avoid and voids/bubbles.