Built a skeletal frame for the inside of the shin parts. This is to provide hard points for connecting the armor to other parts, and to help the foam keep its shape.

It's made from 1/2" PEX tubing.
Then I slipped the structure into the shin...

And since PEX doesn't adhere well to any normal adhesives, I made some retainers to hold it in place.

I ran out of PEX T-connectors (Home Depot only had 9 in stock) so I moved on to the belt. Did the belt buckle with the Templar Cross.

And here's the whole belt in place.

Not too bad for an afternoon's work, even after 3 hours of church, eh?