Hollowing Tools:
An Introduction

Hollowing Tools Overview: One of the hottest areas of interest in woodturning today is turning hollow forms. From the simplest designs to the most elaborate, there is something for everyone to get excited about. Hollow forms can offer a great opportunity to showcase beautiful grain patterns in wood, or they can act as a blank canvass where you can explore a limitless number of embellishments like colouring, piercing, inlaying, burning, overlays, segmented layering, metal leafing, deconstruction, multi-media and more.

Hollowing with the Jamieson
boring bar system with laser guide

If you've been thinking about getting into turning hollow forms, you've no doubt found out that there are many manufacturers offering hollowing tools. These range from small handheld tools all the way up through boring bars that are several feel long. Deciding which tool to purchase can be difficult, since there are so many choices. The first step in deciding which system to purchase is to decide what type of hollowing you would like to do.

Do you want to turn small forms, medium forms or very large forms? What is your lathe capacity? Do you want to use freehand hollowing tools (where you hold the tools in your hands), or do you prefer one of the captured systems (where the hollowing tool is supported, or captured with a secondary toolrest)? Do you want to use a laser for guide during hollowing? What is your budget for tools and accessories?

By answering questions like these, you can pare down your choices to a few systems and then drill down on the specific features of each system to decide which tools are best for your needs. If you're going to be turning hollow forms for the first time, I recommend that you start with either a hand held system (for very small forms like ornaments), or one of the captured systems for medium and larger forms.

Below are a few of the hollowing systems that I use in my studio for turning hollow forms that range in size from very small (2" – 4") to large hollow forms (18"+ in height). Some of these hollowing tools are used freehand; others are captured systems that are used with laser guides. No matter what size lathe you have, from a mini-lathe all the way up to a large heavy-duty lathe, there are hollowing tool systems that will meet your needs. With all of the great hollowing tools that are on the market, there has never been a better time to get into hollowing!

Small Handheld Hollowing Tools

Small hollowing tools are typically handheld and are used for turning smaller projects like weed pots, vases, holiday ornaments, boxes and similar projects. The main limiting factor with these systems is the overall size (shaft diameter) of the tool, which limits the distance you can use the tool unsupported off the tool rest.

Another factor is the size of the project you wish to turn. For example, if you want to turn a miniature holiday ornament, the ¼" shaft on some tools may be too large. In cases like this, most turners choose to make their own micro hollowing tools. A future edition of Lathe talk will discuss simple ways to make your own micro hollowing tools.

Kel McNaughton: Kel McNaughton (Kelton Tools) makes hollowing tools in various sizes that will turn small, medium and large projects. Kel's smaller tools are typically used in Kelton handles freehand and are excellent tools for working with smaller projects like delicate vases and ornaments. By using a small diamond hone on the front face of the cutter, you can easily resharpen the cutting tips. If you want to try hollowing on small projects first, these are great tools.

Various hollowers from Kelton's systems
for captured and free-hand hollowing

Robert Sorby: Robert Sorby's mini hollowing tool set that features a fixed cutting tip, or a swivel tip for better access in tight quarters. These tools are typically used on small hollow forms and vases where the tool does not need to reach very far off the tool rest. They also work very well when turning larger ornaments. Sorby offers a wall thickness gauge for maintaining a uniform wall thickness when turning.

Robert Sorby handheld hollowers

Dennis Stewart: Dennis Stewart’s Omni Pistol is a hollowing tool handle that will accept standard cutting tips that are mounted directly in the end of the handle, or on a curved shaft that is held by the handle. This tool will accept standard 1/4" components in the end of the tool and offers a cushioned grip for comfort. If you like to make your own hollowing tools with 1/4" shafts, this is a good tool to use as a master handle/holder.

Captured Systems with Lasers

When I started turning hollow forms many years ago, nearly all of the systems that were available were used freehand, typically in some type of arm brace handle. This style of hollowing was referred to as "Blind Hollowing," since you were unable to see the cutting tip inside of your project during turning. Blind hollowing was difficult to master and could be fatiguing if you turned for a long period, since the tool was inserted in a handle that was braced on your arm.

Today's newer hollowing systems feature two significant improvements over the older freehand hollowers. First, these new systems are captured, where the weight of the tool is supported in a secondary toolrest. This means that the lathe and its toolrest take all of the stress from hollowing, instead of your body. Secondly, these hollowers offer a laser guidance system that can be set to show you exactly where your cutting tip is located inside the form when you're hollowing. No more blind hollowing!

The laser can also be set to show a gap from the cutting tip, for example 1/8". This gap would represent the desired wall thickness you wish to have on your completed form. When turning the hollow form, the laser will show a red dot on the surface of the project until you reach the proper wall thickness. Once the correct wall thickness is reached, the laser will fall off the surface indicating that you have reached the correct thickness.

Having come from the "old school" of blind hollowing with an arm brace for many years, I can tell you that these new hollowers are the best improvement in hollow form turning that I have seen since I opened my studio. With a captured system and a laser, even novice turners can create hollow forms with ease and confidence. They are easier on your body and far more accurate than blind hollowing. If you want to turn small through large hollow forms, take a serious look at a captured system with a laser.

Kelton Hollowing Rig: The Kelton Rig features a unique "A" frame design to hold the hollowing bar, which eliminates the rotational torque produced during hollowing. This design is fully adjustable for length of the boring bar, as well as the rake angle of the cutter. This hollowing system will accept hollowing bars with 1/2", 5/8" and 3/4" diameter shafts from Kelton, as well as other bars of a similar diameter from other manufacturers. A super heavy-duty 1.5" diameter boring bar extension is available for turning extra deep forms up to 18" or off the toolrest.

Kel McNaughton hollowing
system with laser rig

This heavy-duty hollowing rig offers a safe, easy and controlled method to create hollow forms. The optional laser guide mounts on the hollowing rig and allows you to know exactly where your cutting tip is located inside the vessel. This is a great hollowing rig if you want to turn deeper vessels and you prefer using a captured system instead of a long boring bar.

Kelton 1.5" diameter extra deep boring bar

Jamieson Boring Bar System: Lyle Jamieson's Deep Hollowing System utilizes a "D" shaped receiver handle to hold the boring bar and is used in conjunction with a secondary toolrest. The "D" handle effectively stops the rotational torque created during hollowing, allowing you to hollow your projects with ease and confidence. The optional laser system allows precise control of the cutting inside the form and can be set to indicate a particular wall thickness.

Lyle Jamieson "D" style hollower with dual
purpose boring bar, requires secondary toolrest
for "D" handle. Optional laser rig is available

The standard 3/4" diameter boring bar will allow you to turn with the bar up to 12" off the tool rest. Lyle also offers a 1.125" diameter jumbo boring bar, for turning deeper hollow forms. The jumbo boring bar will allow you to turn up to 18" off the toolrest. The 3/16" cutters are fully adjustable and are easy to resharpen.

Large Arm Brace Systems

These hollowing systems feature an arm brace handle to hold the hollowing bars. This style of hollowing is known as "Blind Hollowing" and requires a high level of skill to master. However, it should be noted that all of these systems could also be used in the handles of a captured system like the Kelton, or Jamieson systems. Although I use captured systems for most of my hollowing these days, some projects benefit from being finished with an arm brace system.

Dennis Stewart: Dennis Stewart's hollowing tools were the first hollowing tools I ever purchased and I used them for many years when I first opened my studio. This system has undergone many upgrades since those early days, but the heart of the system remains the same, an arm brace handle that will accommodate straight and bent hollowing tools. Most of the cutting tips used with this system are the standard 3/16" square cutters. You can also mount teardrop scrapers for finishing cuts.

Dennis Stewart arm-brace style hollowers. This was
my first set of hollowing tools back in the day...

Don Pencil Scorpion System: Don Pencil's Scorpion hollower is an arm brace style hollower, but there are several improvements that make the system nice to use. The hollowing bars are chrome plated, making it easier to move along the toolrest. The chrome plating also makes the hollowing tool shafts resistant to rust and extractive buildup. In addition, the padding on the handle and forearm is very comfortable, making it much easier to hollow for longer periods. Don also offers different sizes of the forearm section, to give a better fit for each individual turner.

Don Pencil arm-brace style hollowers
(cutters removed for sharpening)

John Jordan: John Jordan makes an excellent arm brace hollowing system. It features one of the best curved blade designs on the market. The hollowing blades are also coated to reduce rust. This system uses standard 3/16" square cutting tips, which can be easily replaced when necessary.

John Jordan arm-brace style hollowers

The arm brace handle accepts 1/2" (with optional adapter) and 3/4" diameter boring bar hollowing tools. The curved blade orients the cutting tip in the correct position to reduce the rotational torque created when hollowing. Setscrews are underneath the top of the bar, making removal and replacement of the cutting tips much easier. John's boring bars can also be used in captured hollowing systems if desired.

Robert Sorby: Robert Sorby's RS2000 hollowing system is very similar to the Dennis Stewart hollowing system. The RS2000 features an arm brace handle that holds standard ¾" boring bars. The cutting tips are fully adjustable and are easy to remove/replace if necessary. An adjustable side handle is available that provides additional control of the tool when hollowing.

Robert Sorby RS-2000 arm-brace
style hollowing system

Other Hollowing Systems and Boring Bars

Woodcut Pro-Forme: Woodcut's Pro-Forme Hollowing tool is one of my favorite freehand hollowers. The M2 HSS cutter head on the Pro-Forme produces a shaving, instead of chips like many other hollowing cutters. The cutting head features a safety gauge that limits the cutting depth to help prevent catches. The hollowing shafts are available in three standard configurations a straight shaft, a slightly curved shaft and a deeply curved shaft. These Pro-Forme hollowing tools feature a 5/8" diameter shaft that will reach up to 10" over the toolrest. A very comfortable and well-cushioned tool handle is available to use with this hollowing tool system.

Woodcut Pro-Forme hollowers

Trent Bosch: Trent Bosch's Total Access hollowing tools can be used in Bosch handles freehand, or used in captured systems from other manufacturers. These hollowers are available in 5/8" and 3/4" diameters and very well made with an excellent surface finish. The cutting tips are easily removed for replacement. The straight bar features an excellent tapered shaft, increasing the clearance when working inside your form. Trent's hollowing tools are easy to use and very well made.

Trent Bosch hollowers will fit in
many different hollowing systems

Mike Hunter: Mike Hunter makes a unique line of super sharp round carbide cutters that are fitted into handles that can be used freehand, or as an insert for all of the popular hollowing tool systems. These round carbide cutters can last up to 100 times longer than a traditional M2 HSS cutter and never require sharpening. When the cutter dulls, simply rotate it to a new sharp surface. When you have used the entire sharpened surface on the cutter, it can be replaced.

Hunter #3 and #4 carbide handheld tools. 3/16"
square and round ended inserts are also available
to fit most hollowing systems

These cutters can produce a very smooth surface straight off the tool, eliminating the need for secondary operations to smooth the interior walls on your projects before sanding. The tools pictured are the #3 and #4 Hunter straight tools. A new line of bent "Swan Neck" Hunter tools has just been introduced as well for better access in tight quarters and under the shoulder area on hollow forms.

Large Boring Bars: Large boring bars are useful when working a very long distance off the tool rest. These hollowing tools are always used with a secondary tool rest to help support the heavy weight of the bar. Most large boring bars feature lead shot in the handle to help dampen vibration when hollowing. There are many different types of large boring bars available and many turners even make their own. If you want to go deep, this is one way to produce tall forms.

This 4' long deep boring bar handle can be used
with standard 3/4" boring bars and with larger
(necked down) boring bars as well, for
extra deep hollowing

Hook Tools

Kelton: Kel McNaughton also makes hook tools that can be used for hollowing. Hook tools can be effective on many different types of hollow forms, but they tend to have a steep learning curve with some turners. When mastered, hook tools are a great to use on smaller forms whose design can accommodate the straight shaft of the tool.

Kelton hook tools

Martel hook tool insert for boring bar.
Diamond sharpener is shown below cutter

Closing Thoughts

These represent only a few of the many different hollowing tools that are currently available for hollowing. New articulating systems have been recently introduced, as well as new systems for mini-lathes. No matter what your budget is, you can find a hollowing tool system to suit your needs. These hollowing systems are available from most of the major turning supply stockists. Some are available directly from the individual turner as well. Happy hollowing!

Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.

Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.

Steve is also the current and founding President of the Lone Star Woodturners Association, Inc., an AAW member chapter. The LSWA is a 501(c)3 non-profit educational organization dedicated to teaching and demonstrating the art and craft of woodturning.

Steve is also a featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles in an upcoming issue.