The Process of Building the Base for the New Anvil

This is the base mostly assembled.  We glued up two blocks of poplar for the lid and base.  We then drilled a hole in the top to allow for air flow and to add sand.  We through bolted two threaded rods in the top and bottom to hold the lid and base in place.  The walls are made out of 3/4" marine grade plywood to help stand up to the elements since the base lives outdoors.  The base was assembled with wood glue and screws.  The inside was then painted to seal it and the seams were caulked with silicone caulk to keep out moisture.  The screw holes were puttied over and the flaws in the plywood were also puttied over.

We then polyurethaned the outside of the box to seal the wood.

Here we are filled the based with sand.  The sand takes out some of the bounce, which helps to prevent the anvil base from "walking" on the concrete.

Here we are adding the metal banding to keep the sides from bowing after we added all of the sand.

Here it is all strapped, filled with sand and with the lid in place.

Here we are bolting the anvil brackets in place.

Here it is all finished and pretty. 

Things I would have done differently.  I would have planned the bracket and through bolt placement out a little better, since they are pretty close to each other right now.  After some abuse the through bolts are also taking a bit of a beating and the lid is starting to sink.  Other than that it's holding up pretty well so far.