Scrapers are not only one of the most useful tools you can have when working with raw, unfinished wood, but they are also extremely useful when used during the finishing stage of your guitar.
The typical scraper that we normally take about here is usually made from a harden sheet of steel, between 1/32″ and 1/16″ thick. The edge is filed with a smooth mill file and then the edge is curled with a burnishing tool, or the shaft of a high-quality screwdriver which has harden steel shaft.
These scrapers can make short work of wood scratches and are an ideal instrument to use in close working conditions where it is difficult to use sandpaper. Also, they leave a glass-smooth surface that needs very little additional attention prior to finishing operations begin.
There are many things that can be used as a scraper, as long as the tool has a very sharp edge, it will work as a scraper. I have used such things as single edge razor blades, Xacto knife blades, old pieces of saw blades and – well you get the idea.
As for finishing operations, I find that the single edged razor blades works remarkably well as it is easy to grasp, has a very sharp edge and can easily be replaced when dull. I typically use these scrapers to clean off both plastic and wood bindings, work in confined areas, use on end-grain wood, cleaning off stain from binding on the guitar body, peg-head and fretboard areas.
You can even slot a dowel and insert the safety blade and you have a tool that can be set to a specified width of cut, which really works great for edge bindings, as you can pull it around the guitar body without the worry of cutting into the guitar wood which is adjacent to the binding and purfling.
Place a negative hook angle on the razor blade by dragging the entire edge of the blade along a hardened burnisher to curl the edge to form a burr. This really works great for the harder woods and leveling finish repairs quickly and the best thing is when it is dull, you just toss it and quickly make another one.
Using The New Scraper:
You will find that while a scraper with a negative rake will work really well for hardwoods, it will not work all that will with softwoods, as they tend to pull out the grain. If you wish to work with a scraper on softwoods, you should employ a positive rake of the scraper which will minimize this tearing action. Overall? I basically only use scrapers on the hardwoods and for finish cleanup and save the sandpapers for the raw softwood tops.