I read somewhere on this site that if I put my brush in water that is too hot I could damage it. This leads to a couple of questions. How hot is too hot and how do I know if I have damaged a brush. I have a boars brush and a fine badger brush from franks shaving. I have put the boars hair brush in water straight out of the electric kettle and it didn't seem to lather properly, but after it dried it seems to be just the same as it was before.