Since the silicone fillets on the last mold didn't have the correct radius, I decided to use a different material to create the fillets. I had some wood filler that I thought would do a good job.

Umm, yeah...not so much. This stuff made a horrible mess. Time to think of something else.

I thought it might work better if I reverted to silicone, so to do a test, I covered a couple test blocks with contact paper. Instead of dragging the radius tool across the silicone...

...I would cover it with waxed paper. The theory is that the silicone won't stick to the waxed paper (nothing sticks to wax, right?) and having the paper barrier between the fillet tool and the silicone would prevent the silicone from being dragged by the tool. I laid down a bead of silicone...

...pressed a piece of waxed paper over...

...and used the tool to form the fillet.

Hrm...during the forming of the fillet, the paper was kind of crinkling. I didn't get a good sense that this was going to work very well.

Here's another view...the light catches the fact that the waxed paper isn't very smooth. Well, nothing to do but let this cure.