Here's a few shots of casting a custom builder's plate for a new boat. It's fun and easy!
First, carve yourself a pattern and make a petrobond/olivine sand mold inside your casting flask:
Next you melt some silicon bronze alloy in a crucible, and then pour it into your prepared sand-mold:
When you break open the mold and pull out the part with tongs. . .
. . .don't be surprised if it catches fire again once exposed to a fresh source of oxygen. This is perfectly normal.
Now you just have to cut off all the sprues and risers, clean off the carbonized residue and give it a good polishing.
Next you'll need something to mount your builder's plate on, so gather up some cedar and oak and whatnot, and make one of these.
The final step is to screw that plate on with matching bronze screws. There, now that wasn't so hard, was it?