I wanted a book safe and didn't like the versions that I saw that looked like they were hacked out with a rusty hatchet. So I came up with my own way of making one.
Thick book - find a book that will look like it belongs in the bookshelf. Don't put "The Works of Shakespear" in a shelf with electronics books just because it was the right size. It looks out of place. Better to use that book "10,000 Electronic Diagrams" that you never use anymore. You can get really nice thick well built books for free or very cheaply at garage sales, library sales, old book shops or just around the house. Just ask for permission if it's not your book.
A sharp utility knife or single edge razor blade or exactco knife
Band saw (recommended) or coping saw (useable)
6 min. epoxy or thin super glue - I like 6 min. epoxy because it is thick and will stay where you put it and I'm sensitive to the fumes of super glue.
Strong cloth or paper to reinforce the binding if necessary.
Step 1: Removing The Cover
Lets get started!
The better book will have a binding that looks like this. The cover of the spine is separate from the actual spine of the book and you can just cut down the hinge line and separate the cover from the pages.
If the cover is not separate from the spine carefully peel it away after you have cut at the hinge line.