first fish drumming

[Low T]

I did my first fish yeaterday, a perch, I made a half cast of plaster, cleaned and filled the fish, closed it up and this morning I see some drumming on the wall/back side of the fish. Do I worry about this, or inject it with glue?   

[Todd B]

I have never had this happen to me before.  But if the front show side is fine I would not worry about it.  Noone is going to see it.  My question is what is causing it to drum?  I have mounted fish without any glue before and never experienced drumming. 

Todd B

[den007]

How would you get drumming with fish fill? Especially on day 2 of the longer drying process. I can't even picture this.

[Frank E. Kotula]

Take a syringe fill it with regular caulk and inject the area that has a void in it.