Do you know where Ed sources his carbide rods? I have made several scraper burnishers, but am always looking for a cheap, reliable source for rods. I don't mind buying them in bulk, eg., 10 or 50 at a time.
I think burnishers work better with ferrules, since the carbide is very short, and there is a lot of lateral pressure, which makes it easy to split out the handle. Are they 6 mm or 1/4" ø? I prefer Imperial dimensions, because they fit the brass compression nuts I use.