Woodturning Scrapers are extremely versatile and are used for a wide spectrum of applications: surface smoothening, bowl finish work and interior enlargement are some examples.
Novice woodturners believe that having a set of roughing gouges and chisels is all you need. Although you can accomplish a lot with those tools, you should invest some time in learning the scraper and applying it to your projects. The impact this tool will make on your work is absolutely worth learning how to use the tool.
In this article, I will go over some of the common scrapers and how to properly use them for different applications. I will cover the different styles of scrapers ranging from narrow gauge to heavy duty bowl scrapers. Finally, I will touch base on how to properly maintain a scraper in your inventory; the biggest focus being on sharpening your tool.
Woodturning Scraper – The Main Purpose
Every tool in a woodturner’s arsenal is aimed at removing wood from a larger block in order to create the desired shape. Although this goal is shared by all tools, the process of removing said wood varies. A different outcome can be achieved by leveraging the different ways a tool interacts with the surface of the wood.
A wood scraper falls into a category of tools which will ride the surface and remove a thin layer of grain while smoothening out the surface. Unlike a gouge, the wood lathe scraper blade is positioned lower than the tool rest of the lathe in order to receive the wood. Although it may seem like a small detail, the surface is subjected to a lot less stress which results in a much smoother finish.
The Wide Array of Scrapers
Scrapers come in many shapes and sizes. Depending on your particular application, you should choose a certain type of scraper.
If you are getting started in woodworking, it is highly recommended to invest in a medium-sized round nose scraper. Although it may not be suitable for all applications, it’s easy to work with, can be used in many projects (such as turning a baseball bat) and is generally the first stepping stone in learning scrapers.
Round Nose Scraper – Also known as the “dome-shaped scraper”, this tool is often used for work on bowl surfaces. The blade is curved at the edge which allows a skilled woodturner to work with curved surfaces. The width of the blade, as well as the curvature radius, can vary. A smaller radius will typically allow you to work on a wider range of surfaces, but will require more precision and take more time if you’re working on a surface with less of a curved feature.
Left/Right Side Curved Scraper – This tool will provide you with a blade with a curved surface which varies as you progress from the tip to the end. the tip will start off as a straight blade and gradually morph into a curve on the specified side. The curve is generally of a larger diameter than the one on the round nose scraper which means that you can leverage this tool for large diameter bowls.
Square Scraper – The square scraper features a straight blade perpendicular to the tool handle. It is the perfect tool for working on spindles, furniture poles, pens and other flat surfaces. By using this type of scraper, you can easily smoothen out a surface while creating a perfectly straight design. Skilled woodturners can vary the angle of this tool to create “V” cuts.
Other Types – While shopping for a scraper, you will notice a lot more options. Specialty scrapers are used for niche applications. For the purpose of this tutorial, we will focus on the most widely used tools and assume that as your experience grows, you will know how to select the right scraper for your application.
Scraping The Surface
The difference between cutting and scraping is in the angle at which the tool is positioned as it relates to the surface it comes in contact with. In other words, assuming a rest tool height to be at the same level as the center of your spindle, the tool will cut if the blade is positioned higher than the handle. If the blade is placed below the tool handle, the tool will scrape the surface.
To understand this concept better and what is actually happening, picture yourself with a simple knife. If you position the knife blade first and start moving it into the wood, your blade should cut into the wood. As you live the blade, you’re left with a wood shaving which will increase in size as you make your way deeper into the surface. On the flip side, if you drag the blade across the same surface, you will notice that the blade is barely making contact and removing only a thin layer off the top.
What is the Burr?
The action of scraping is relying heavily on the heel of the blade called the burr.
The burr is difficult to see as it presents itself as a minuscule bump right before the edge of your blade. However, it’s easy to feel and if you slide your finger away from the tool, you will feel it immediately.
The burr is created by sharpening the scraping tool. As the scraper comes in contact with a grinding wheel, metal is removed from the bevel. Although it seems that metal has completely vanished, small “lips” are formed on either side of the blade as metal is trying to scape.
The burr will happen naturally as you work with any tool, but you would usually remove it by sanding it down. In the case of a scraper, you want to leave the burr as is.
Forming a Burr by Burnishing
Another way of creating a burr on a scraping tool is by burnishing the edge. In short, you are forcing the sharp end of the blade against a fixed object in order to create a lip as it deforms.
A typical rig to get this done will consist of a pivot pin and a burnishing pin. As you move the tool around the pivot pin and force it again the burnishing one, the tool forms a burr.
This method is primarily used for traditional woodworking scrapers and less for woodturning ones.
Working with a Woodturning Scraper
If you’ve worked with gouges, you will have an easy time transitioning into scrapers. However, you do need to pay attention to your tool positioning and to make sure that you aren’t using your scraper as a gouge. If you are new to woodturning, I would advise learning how to use a gouge properly before diving into scrapers. However, many of the principles apply to both tools.
Position the tool rest at the same height as the center of your object. Place the blade on the tool rest horizontally. Allow the bevel of the tool to ride the surface of the wood. This step seems unnatural to most beginners, but you’re letting the tool slide against the surface without actually cutting or scraping. This is done in order to feel the surface and properly position your tool where it needs to engage.
Once you’re ready to strike the wood, raise the handle of the scraper (notice that if you’re using a gouge you should be lowering the handle). As the burr makes contact with the wood, it will begin to scrape a thin layer from the surface. Do notice that exercising more force does not allow the tool to scrape more; the volume removed is limited by the depth of the burr. Remember, the goal of your scraper is to smoothen out the surface; not to remove large volumes of lumber.
Heavy Duty Bowl Scrapers
If you enjoy turning bowls, you will definitely benefit from learning how to use a scraper and applying the technique before the finish. A skilled woodturner will be able to leverage a heavy duty scraper on the interior and exterior of their bowl and give it an excellent finish.
Although not extremely practical in my opinion, some individuals are able to turn complete bowls by using only a scraper. Here’s an excellent video showcasing exactly that.
Conclusion on Scrapers
Scraping Tools are an excellent addition to any woodworker’s toolbox. They provide an easy way to work the surface after completing your piece.
The tool is used very similarly to a gouge or any other woodturning tool but does require you to raise the handle instead of lowering it. It takes a little time to get used to but isn’t extremely challenging.
Lastly, properly sharpening your tool and making sure that the burr is present is crucial. Scrapers don’t get dull, but rather lose their burr and just stop removing wood. Keeping an eye on how the burr is doing is important.