On Friday, May 15, 2015 at 11:48:39 PM UTC-5, wrote:
I just did the same thing. I hope my brush isn't ruined. I soaked it in hot soapy water and it is still hard..

My personal opinion is that most people don't clean their paint equipment properly. Not brushes, not rollers, not guns... none of it.

If you have a brush with dried material on it, it is now a "dusting" brush. No longer will it give a satisfactory finish.

Once the material has dried and lost its plasticity, it is simply a hard resin or even plastic. You can revive the to some extent with a good quality stripper, or do the right thing and clean brushes and rollers immediately after use with the correct solvent.

BTW, using a pet comb, a wire brush or any other kind of device to "comb" or tear out the dried residue will ruin the brush for everything except painting rough sawn exterior materials. The flags (flagging) on brush bristles that leave the fine finish are torn apart and in some cases completely off the brush when a wire comb or brush is used on them. Additionally, they will not remove any of the dried residue in the brush well, so in effect you are simply wasting time unless you need a good duster.

Robert