If you are unable to sharpen a cabinet/card scraper using conventional methods, there are a few alternative approaches you can try:
Replace the blade: If your current scraper blade is too damaged or difficult to sharpen, consider purchasing a new one. Many woodworking supply stores sell replacement blades that can easily fit into your cabinet scraper.
Use a burnisher: A burnisher is a hardened steel rod that can be used to create a new edge on a scraper blade. It works by deforming the metal on the edge of the scraper, creating a burr that functions as the cutting edge. While it may not be as precise as traditional sharpening, it can still produce a functional edge for your scraper.
Try a file or sandpaper: If you have a coarse metal file or some abrasive sandpaper, you can attempt to smooth out any nicks or imperfections on the scraper blade. Be cautious with this method, as it may take some patience and skill to achieve the desired edge.
Seek professional help: If you're still struggling to sharpen your cabinet scraper, consider reaching out to a professional woodworking tool sharpening service. They have the expertise and specialized equipment to sharpen the blade properly and restore it to its optimal cutting performance.
Consider a scraper plane: Instead of using a traditional cabinet scraper, you could try a scraper plane. A scraper plane is a hand plane with a built-in scraper blade that can be adjusted and replaced easily. This might be a more straightforward option for maintaining a sharp edge, especially if you find traditional cabinet scrapers challenging to sharpen.
Remember that cabinet scrapers are meant to be versatile and disposable to some extent. While sharpening is an essential skill for a woodworker, it's not always possible or practical to sharpen certain tools repeatedly. If all else fails, don't hesitate to explore the above alternatives or invest in a new scraper blade or tool.