The other day I was cleaning one of my pipes and I realized I have a chunk of cake missing in the bowl. Figure I didn't let the pipe rest as it was my second pipe that smoked better than the first and thus got smoked a lot. So I'm curious as to what I should do to fix it. Should I just ignore it and let it rebuild itself (haven't as I figured the uneven cake could cause the pipe to crack), or get a reamer and ream it so its all the same thickness? And since it's happened once now, is there a way to prevent this from happening again?