try gluing a metal tube (stainless?) into your stem
This is probably the way to go. I think Vermont Freehand has the tube.
your pipe design is something similar to the ornsby pipe
Yes. That's exactly what I have in mind.
Would your designs be suitable as Falcon bowl types?
Actually, that's what the blocks were cut for. I bought a dozen or so of these on eBay, and if I remember correctly the seller said they were old Dr. Grabow blocks designed for the Falcon bowl type.
I've made one pipe (see below) from them, but the chamber wall is so thin that the bowl gets too hot to hold. If I thicken chamber wall I can't have a shank at all. The briar is pretty nice with minimal flaws. Anyway, I'm having fun with what I have and I think the metal tube may be my solution.
Metal plus hot smoke equals condensation.
Bummer! I think I'll still give it a try, but we'll see how it smokes
Here's a pic of the pipe I made and the size of block that I'm working with. As I said, the chamber wall is too thin.

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