I've successfully removed the knots from about 8 brushes so far. Today I was working on an Ever Ready, as soon as I inserted the drill into the knot the entire handle shattered. It looks like it had a really thin plastic shell over plaster. The fur seemed to be glued into a thin plastic cup, which was glued to the plaster, not very well as it snapped into pieces as well. Any thoughts on how this could have been prevented? It's by far the cheapest materials I've seen in a brush, any idea if that signifies a more recent product?