One thing I did do was take a couple of pictures of the knee protectors, in order to post them here:
This is the inside of the lower piece resting within the kneecap protector, and you can just see that I have the middle joint taped with blue tape while the glue dries.
Here is the lower piece within the kneecap piece, showing how they will overlap. I am planning to rivet them together, one on each side, so that they can rotate with my knee when I bend it.
After taking these photos, I decided I wanted to start working with the Worbla and see if it lives up to everything I have heard. And so far, it really does. It has a rough side and a smooth side. The smooth side is actually a thin coating of glue. You can warm up the Worbla, and the glue will soften along with it, becoming sticky. When it cools, it's no longer sticky and can be handled with bare hands. A heat gun works perfectly to warm up the plastic, and it softens in less than a minute with the gun held a couple of inches away from the surface. When it gets warm and soft, the plastic darkens just a little bit, becoming almost translucent. The glue isn't quite ready at that point, but you know you're getting close. A few more seconds, and the plastic will become very soft. The glue is also nice and sticky by then, and the piece can be applied to whatever you want at that point.
Here are some more photos of my testing, and my first couple of applications.
Worbla comes in rolls like this. The outer face is rough, but the inner face is smooth (the glue facing).
Here's a piece of scrap Sintra that I used for testing. I cut a small strip of Worbla from the roll, then held it to the Sintra and used the heat gun to warm it up. After a few seconds, the glue melted to the point where it was sticky, and the plastic itself was plenty soft to make it follow this gentle curve.
Same testing piece. I positioned the Worbla such that there was about a quarter inch of excess past the edge of the Sintra. Keeping it nice and warm, it was easy to fold over the edge and stick to the other side.
A better angle showing the Worbla folded around the edge of the Sintra. After it cooled, the glue held it quite firm. I had to use a razor knife to peel it away at all, and even then it required me to reheat the Worbla so that it became soft.
This is a real piece of the armor, part of the breastplate. I ran one strip along the long curve first, overlapping the edge just like the test piece. Then I added a very short piece at the end, and pressed the edges together so that the seam became almost invisible. It shows here, but when it is painted over, you won't see it.
Close-up of the edges and seam.
Here is the piece on place on the breastplate. As you can see, the main breastplate overlaps it, and there is another flap behind and below which will also get a Worbla edging strip like this one. In fact I intend to put this edging on just about every piece of armor that I have.
Here are my vambraces (forearm protectors). I cut the Worbla into one-inch wide strips, attaching just over half an inch along the edge, and wrapping the remaining width over the edge and into the backing. You can see the inside edges at the bottom of the photo, the Worbla doesn't always wrap cleanly along a curving line. I'm not too worried about this, since it the inner edges be hidden when I'm wearing the pieces anyway.
The outer face of the vambraces.
And that is as far as I got in a couple of hours working today. I'll do some more work today, but clearly this is going to take quite a few hours to complete all the decorative edging. The good thing is, the Worbla appears to be just as easy to work with as I have heard from others. It's kind of expensive, especially compared with cheaper materials like Sintra, but for decorative edging and other things it is really nice to work with and you don't need a lot.