How to Sharpen a Bowl Gouge? Detailed Guide
You can’t be a woodturner without sharp tools. And a sharp bowl gauge is essential for making a stunning bowl. Most of the time, these gauges are not ready to do fine work right out of the packet. So, they must be shaped, sharpened, and honed to fit your needs.
Although a bit tricky, knowing how to sharpen a bowl gouge is one of the most important skills for any woodturner to master. And sharpening once won’t do either.
A frequently used tool like a bowl gouge will only stay sharp for so long. Therefore, you must also know when to sharpen it again so that your woodworks remain uninterrupted.
What is Sharpening?
When you talk to woodturners, you’ll notice they use the word sharpening and grinding interchangeably. Don’t let it confuse you.
Grinding theoretically means removing a great amount of metal that we don’t do while sharpening. A grinder is mainly used to sharpen the lathe tool and not the bowl gouge.
While sharpening, we are only removing a small amount of steel. Sharpening is, therefore, not doing anything else other than restoring the sharp cutting edge of the bowl gouge.
How Does Sharpening Work?
When we use a bowl gouge, its sharp edge gets dull over time. So, it needs to be restored to work again. And the area that you need to pay attention to here is the bevel, which is the flat but round area around the sharp edge.
It is important to grind the entire area of the bevel and not just the edge. This means, while applying the sharpening technique, we are actually smoothing out the whole surface of the bevel. This results in the restoration of a sharp and crisp cutting edge on the bowl gouge.
When to Sharpen?
There are several indicators to let you know when to sharpen the bowl gouge. The main indicators are color, temperature, results, and time.
Bowl gauges are made from high-speed steel (HSS), which sometimes turns blue as you grind. There is nothing to worry about as this doesn't soften the steel. If you notice a color change, maybe it is time to practice your bowl gouge sharpening techniques.
Dulling down of the bowl gauge increases friction while turning. This friction causes the tip of the gauge to heat up. If the tool becomes too hot to hold, don’t put it in water, but rather keep it in dry air to cool down. You can also lay it on any metal surface to dissipate heat faster.
The performance of turning is reduced with the dulling down of the bowl gouge. So, the easiest way to tell if the performance is decreasing is when you notice it producing chips or dust of wood rather than making longer shavings.
Another smart indicator is when you actually feel that you need to sharpen the gauge. If you can’t remember when you last sharpen the tool, it is probably time to sharpen it again.
It actually comes down to the usage of your bowl gouge. If you think you’ve used it enough, then probably you should sharpen it. But in case it hasn’t been used that much, then don’t bother at all.
The Sharpening Angle
The angle for your bowl gauge mainly depends on your personal preference. This will determine how you maneuver the tool, create each cut on the lathe, or even how you stand.
Usually, woodturners shape their bow gouges into three basic styles based on the angle; traditional, fingernail, and swept-back styles. Some other approximate gouge sharpening angles are 40-40 grind, modified fingernail, Irish grind, and micro bevel grind.
We do encourage different angles for beginners to hone their skills and find out which suits them best. Bevels which are closer to 30 degrees give a better tool control. So, starting with a relatively short bevel might be a good start for beginners.
The Grinder and the Stone
Set up your grinder high enough so you can easily see what’s being accomplished. Check if the whole machine is balanced so that there is no vibration during the sharpening process.
As for dressing up the stone, give a few strokes across the running wheel with a diamond wheel dresser. This will expose a fresh layer, removing any embedded metal particle of its surface.
Mark the Bevel Black
Sharpening the gauge requires precision, and in order to get that, marking the bevel helps out a lot. Since the whole surface of it needs to get grinned, blackening it lets you know which part got neglected.
You can use a felt-tipped marker to darken the bevel surface to see the part of it, which ends up touching the wheel.
Maintaining a continuously smooth and sharp cutting edge consistently is the ultimate goal of sharpening a bowl gouge. So, each time you go to the sharpening wheel, you must be consistent.
Achieving consistency requires practice since the bevel surface area is tiny, and only a small amount of metal is removed. To restore the sharpness, you don’t want to do additional grinding and reduce your gouge to a stub.
Using a Jig
We suggest using a fingernail sharpening jig to make things easier, although lots of woodturners do it by hand. Undoubtedly, this is a great skill to have.
Sharpening a bowl gouge with a sharpening jig is very simple, quick, and efficient. You can have a sharp cutting edge within a few seconds if you do it properly. The result will also be consistent and repeatable.
Sharpening the Gouge
Here’s six simple steps to follow in an order;
1. Positioning the Gouge
The first step is to position the gouge in the jig with the pointed leg of the jig facing down and backward. Tighten the thumbscrew completely. Now, loosen the sliding jig holder so that you can adjust the angle.
2. Adjusting the Angle
To adjust the angle, place the jig leg into the arm end of the hold and touch the bevel on the wheel. Of course, make sure the wheel is off beforehand. You can slide the holder to adjust the angle.
3. Verifying the Angle
A nice trick to ensure your angle is correct is by sliding the wheel little with your hand while touching the bevel on it. The wheel will scratch the bevel surface, and you can check if the scratch is continuous. If it is so, then the angle is correct.
4. Turning on the Grinder
Tighten the extension holder. Turn on the grinder and get it up to its proper speed. Now using fluid movements, the bowl gouge is to be rolled from one end of the bevel to the other.
5. Maintaining the Gouge at the Center
Try to keep the gouge at the center of the wheel. Give the same amount of time to all areas of the bevel against the sharpening surface.
6.Finishing Up and Inspection
After a few seconds of sharpening, remove the gouge, and inspect the progress. If the cutting edge is smooth and the bevel is shining all the way through, then you're done. Should you see any spot or interruptions in the smoothness, then go back to the wheel.
7. Sharpening without a Jig
This is fairly the same process as before, less the adjustments of the gouge to the jig. You might want to try keeping your hand steady while sharpening. Practice keeping the angle fixed on the wheel quite a few times before you turn it on.
Adjusting the angle is also similar to the previous method. Coloring the bevel helps out a lot here. When you slide the wheel keeping the bevel on it, an even stripe through the top to the bottom of the bevel will show if the angle is right.
Your hand might shake a bit at the beginning, but don’t worry. With a bit of practice, you’ll be a pro at sharpening a bowl gouge in no time.
Learning how to sharpen a bowl gouge is as easy as sharpening the gouge itself. At first, the task might seem daunting. But the entire process eases after spending a few sessions at the grinding wheel, and sharpening becomes like an old habit.