There are many ways to make a scraper blade for a Biax, or to make a hand scraper. Home shop built ones are common, just do not go too far away from the tried and true until you have enough experience to truly understand what you need and have learned through enough practice to know pretty well what works best for you. A chunk of carbide brazed or silver soldered or clamped to a 1 x 1/8" shank, and a file handle or similar at the other end, and you have a scraper ready to go to work after the blade is ground into something useful for scraping. The tools are not the big thing, the knowledge of how to test machinery and surfaces, along with how to work the surfaces to something correct for the application, is where training and practice and mentors become quite important. In my experience, none of this comes naturally, it is learned from those who understand it.