How to Use a Center Finder

Riveting is a fast, no heat way of connecting components.  But finding the center of metal blanks can be tricky. So this tutorial shows you how to use a center finder to make riveted earrings.  Finding the true center especially of round metal blanks is much easier with this simple carpenter's tool. All kinds of components - bead caps, rondelles, small metal blanks, can all be used to stack up unique designs. 

How to Use a Center Finder
The center finder tool has two sets of ridges at 90 degrees on one side and at 60 degrees on the other. You can use either side for round blanks.  Just place the round blank firmly against the two ridges. 
While still holding the blank against the tool, flip it over and use a pencil to make a line against the edge which denotes the diameter.  You don't have to draw a line from edge to edge. Rotate the blank and make another mark.
I found it more accurate to make 3 lines to mark the center.  It makes sense to use sharp pencils as broad lines will lead to inaccuracies.
The flower blank is just a modified circle so do the same as for round blanks.  But I think I have to be extra careful and maybe place one petal into the corner where the ridges meet.  I was slightly off center for the flower blanks as you can see from one of the images below.  So I repunched the hole i.e. made it a bit bigger towards what should have been the center of the blank.
You don't really need this tool for squares as you can just get the center by drawing diagonals.  Note that the 60 degree side of the tool cannot be used for squares (unless you are coming up with off center designs).  One corner needs to be wedged into the corresponding corner of the tool.
One word of warning. Do not use marker pens on patinated discs. They are difficult to get off - they do not rub off and mild solvents like isopropanol didn't work and removed some of the patina!!  I found that out the hard way.