Good morning to all:

I have to modify some engine castings to make them solid, non-shelled pieces; these parts will be placed on the web for customer download, but the client I'm doing the work for doesn't want the inside of the casting to be seen; think of it as permanently filling in a jello mold.  Is there a simple trick to doing this?  Thanks in advance for any replies!  (I cannot post any pics because of confidentiality reasons)