Using The Sanding Solution
to Sand Inside Hollow Forms

Sanding inside hollow forms is now
much easier thanks to The Sanding Solution

Overview: For most of us, the evolution into turning hollow forms comes rather quickly in woodturning. Although many of us start out with turning pens, bowls, platters or other types of projects, the desire to turn hollow forms is strong and unyielding. There is something intensely satisfying about turning a hollow form and exploring the many different facets of these elegant artistic forms.

In the early days of my studio, I turned all of my hollow forms using a technique known as "blind hollowing," using traditional arm brace style hollowing tools. Back then, the real challenge was learning to turn the interior when you can't see what you're doing, hence the name blind hollowing. Thankfully, new captured (anti-torque) hollowing tools are available that significantly reduce the amount of time necessary to become proficient with turning hollow forms.


Captured Hollowing Systems

Most of the newer captured hollowing systems offer a laser guide accessory that allows you to know exactly where your cutting tip is located inside the form. Once setup, the laser projects a red dot on the surface that indicates the end of the cutting tip. The laser guide can also be set to show a pre-determined wall thickness - for example 1/8."

Using Lyle Jamieson's laser-guided
hollowing system on a Maple hollow form

When you near the correct thickness, the laser's red dot will change from a round dot to an oval shape. Once you've reached your preset thickness, the oval laser dot will fall off the side of the form and disappear from view. (Note: The laser will appear on the lathe bed, but it will no longer show on the form when you reach the preset thickness).

All of these improvements have made hollow form turning easy to master, even for beginning woodturners. They have also made it easier on the turner, since the lathe and tool rest are taking all of the vibration and torque generated during the hollowing process when using captured systems. Traditional arm brace hollowing tools are still popular with many turners, especially with those who long ago mastered the necessary blind hollowing skills, so there is something for everyone.


Sanding Inside Closed Forms

While there are lots of new hollowing tools available for you to choose from today, there are still very few ways to effectively sand the interiors of your hollow vessels. Back in the early days of my studio, I used a modified boring bar that was drilled at an angle to accept standard 2" hook and loop sanding mandrels to sand the interiors of my hollow forms.

When the interior hollowing had been completed, I removed the primary boring bar and installed my modified sanding bar for sanding the interiors of my forms. This worked to a treat at the time, but the sanding mandrel was fixed into position with a grub screw and did not rotate. This left an interior surface that occasionally contained residual sanding scratches. To get rid of them, I would use a smaller bar by hand (with the lathe off) to hand sand the interior walls to remove any remaining scratches. This was not an easy task, but it got the job done.


The Sanding Solution

The Sanding Solution's inertia-powered sander

Thankfully, I no longer have to use my old modified boring bar to sand the interiors of my hollow forms. These days, I use a sanding tool called "The Sanding Solution." This is a passive, or inertia type of sander (non-powered) that uses the rotational force of the spinning work to rotate the sanding pad. This tool can be used in many different ways to sand the exterior and interiors of woodturning projects.

The Sanding Solution's head is easily
removed for use in boring bars

I've used lots of passive sanders over the last fifteen years and none of them really offered the same smooth spinning action of The Sanding Solution. Another excellent feature of this tool is its removable sanding head. The ability to remove the sanding head makes this impressive tool even better, because you can mount the head in your boring bar and use it in combination with your captured hollowing rig to sand inside deep vessels.

The articulating head can be
positioned at various angles

This means that you can now effectively sand inside deep forms with the same precision and control that you enjoyed when you hollowed your project with your captured hollowing rig… Sweet! Another great feature is the articulating sanding head. This allows you to orient the face of your abrasive in the best possible position when sanding, even under the neck area on your hollow form!

One of many different angles that can
be obtained with the articulating head


Using The Sanding Solution in a Boring Bar

The sanding head is easily removable by loosening the two grub screws that lock the head into the handle of the tool. Once removed, you simply remount it into any standard boring bar and lock it into place with the grub screw on your boring bar. You will need to adjust the angle of the head at first, until you find a good angle that will spin the disk effectively. This takes a minute at most and you're good to go. If you've never sanded the interior of your hollow forms using your captured boring bar system, you're in for a real treat. The control and precision afforded by this mounting is amazing. It makes an otherwise dull task into something that is actually fun!


Using The Sanding Solution's Secondary Handle

Another way you can use this tool is with the supplied handles. If you do not own a captured boring bar or an arm brace style of tool, you can still use this tool for sanding projects some projects that you hollow with scrapers, or other hollowing tools. You can also use it to sand bowls, platters and many other types of projects. The tool can be used freehand on the outside of projects and on the inside of projects like bowls and platters.

The Sanding Solution with 5" and 7" handles mounted

By mounting the optional 16" extension handle you can reach even deeper, but you must use the tool in combination with your tool rest for safety, when the extension handle is mounted. The versatility of this tool allows you to cover a wide range of projects from smaller bowls through deeper hollow forms. The ability to use the tool in a boring bar makes an otherwise difficult task, faster and more efficient. You'll also get a more uniformly sanded surface on the interior, since you can control the head easier than other methods for sanding inside deep hollow forms.

The Sanding Solution with both
handles and the 16" extension mounted


Tips for Use

  • As with any sanding procedure, you should use light to medium pressure when using this tool. Pressing hard will only make your task harder, not easier. In addition, pressing hard will cause excessive heat to be transferred into the wood, which can cause checking. It can also cause the tiny hooks on the surface of your sanding pad to prematurely wear out. The rule here is to sand with the least amount of pressure possible and to frequently change your abrasive sanding pads.
  • The mounting socket on the sanding head is precision machined and must be used with the precision machined sanding mandrels offered by the manufacturer. Two types of precision machined hook and loop sanding disc pads are available, a cream coloured pad for use with course grits up to 180-grit, and a softer gray foam pad that is used with finer finishing grits, 240 and higher. To distinguish these special sanding discs from others in your inventory, they are made with red tops. Abrasive disc holders are available in 2" and 3" sizes.

The Sanding Solution uses precision
machined sanding mandrels

  • When sanding inside vessels, a wave edge abrasive disk will help to eliminate burnishing, or scratches left by the side of the abrasive pad. If you do not have any wave edge disks, you can get a similar effect by using a 3" abrasive pad on a 2" pad. The slight overlap will allow the disk to sand the side of decorative elements instead of scoring them, in case you accidentally brush up against one when sanding.

The manufacturer offers a great instruction sheet on how to use this tool, complete with photos showing proper setup and use on various forms.


Sources

For additional information on The Sanding Solution, please contact Bruce Hoover. The Sanding Solutions Users Guide is located here.


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.