Fluid Texturing with the
Arbortech Mini-Grinder

Fluid Texturing Overview: Significant amounts of woodturnings today feature some form of surface embellishment. This after work on the surface of turnings is a natural progression from the singular beauty of a simple and graceful form. Woodturnings with surface embellihments have always appealed to me.

In fact, the magnificent carved and textured vessels of John Jordan (Antioch, Tennessee U.S.A.) inspired me to become a professional woodturner. In a production studio however, there is little time to incorporate labour intensive artistic features into my production pieces. However, I continually strive to discover new ways to add additional artistic elements to my production woodturnings.

Arbortech rotary carving blades (from upper left to lower right) Industrial Carver, Pro-2 Woodcarver, Pro-3 Woodcarver, Mini-Industrial blade, Mini-Grinder steel blade and Mini-Diamond blade. Mini-Sanders in metric 40, 60, 80, 120 grit

The real challenge however, is how to add these artistic elements within the brutally tight time constraints of traditional production work. Thus, an inner battle has always raged in me between the practical production turner and the creative artistic turner. To nurture the creative spirit within, one must occasionally fan the flames of innovation.

In my studio, "Quasi-Artistic" production work has been a pleasant compromise between the rigid confines of repetitive, predictable production work and the supreme inner pleasure derived from pure artistic work. (Quasi-Artistic turnings feature too many artistic/design elements to be called true "production work" yet too few to be called true "artistic work.")

The Birth of Fluid Texturing

When I first began using the Arbortech Industrial Carver, I immediately knew it offered a plethora of uses for woodturners. Initially, I used the Industrial Carver to remove large or unbalanced areas, prior to giving the blank a go on the lathe.

This allowed me to start roughing out at a much higher initial speed, than removing these areas in the traditional manner with a gouge. Subsequently, I found that the Industrial Carver also excelled at removing bark, whilst revolving the piece at a slow speed on the lathe.

This saved many trips to the grinder with my roughing gouge, especially when working with bark that contained large amounts of imbedded grit, or sand. It was during one of these bark-stripping sessions, that my idea for “Fluid Texturing” was born.

Industrial Carver with 100mm (4") blade, fitted to a Bosch 1375-A angle grinder with the clear polycarbonate Pro-Guard attached

On several occasions, I noticed when I had stripped the bark off the log the side grain was left with a nicely textured surface. With my curiosity peaked, I began experimenting on ways to use the various Arbortech tools on the lathe, to rapidly create elegant textures.

The fluidity and speed of this process is quite addictive. Textures can be created in a few seconds that would take significantly longer to accomplish by traditional carving methods.

Texturing a turned piece whilst it is in motion, or “Fluid Texturing” as I call it, completely fascinates me. The textures created by this process add a unique visual and tactile allure to the piece that is difficult, if not impossible to attain by other methods.

In Fluid Texturing, a unique symbiotic relationship is created between the tool and the timber, each dependent on the other, to reveal the beauty of the combined union. The textures created from this union are almost limitless and serve as a catalyst for the exploration of this new artistic form of expression.

Fluid Texturing Basics

Arbortech PTY Ltd, of Australia (www.arbortech.com.au) makes the power carving tools that create my Fluid Texturing embellishments. These rotary power-carving tools attach to standard 4" – 4.5" (100- 115mm) angle grinders. They are one of the few rotary power carver blades that conform to strict European BG safety standards, regarded as the toughest in the world.

The unique design of the safety rakers on each blade produces a maximum 1mm depth of cut with each pass. This eliminates kickback and grabbing, resulting in a smooth and easily controlled tool. The larger 100mm Pro-2 and Pro-3 blades produce an average 3.6 million shaves per hour, which provides rapid and controlled stock removal.

Many turners who use these Arbortech tools texture their turnings off the lathe, whist the piece is stationary (i.e. “static” carving). Others will carve or texture their turnings on the lathe, but the work piece is held stationary. The lathe acts as a carving vice to securely hold the work, whilst the piece is being carved or textured. While I have the utmost respect for these traditional methods, I love the fluidity, speed and creativity offered by using these tools, whilst the work piece is revolving on the lathe.

Production turners like things that move very fast. Actions and movements are continually honed to produce the highest quality work in the shortest time possible. In a production studio, each second is precious and these tools can produce provocative textures in the blink of an eye. The resulting turnings can be sold for more than traditional turnings, with a minimal additional time investment required.

Fluid Texturing with the Arbortech Mini-Grinder

The Arbortech Mini-Grinder is a superbly crafted tool for Fluid Texturing on the lathe. The small head of the tool, coupled with the availability of Tungsten Carbide cutting blades, offers maximum flexibility in the types of textures that can be produced.

The Mini-Grinder can create textures that are very delicate, or strong aggressive designs. These textures capture and reflect ambient light, which gives the impression of visual movement in the piece.

Mini-Grinder fitted
with 50mm (2") Mini-Industrial Tungsten Carbide
blade on a Bosch 1375-A angle grinder

The standard steel blade offers a maximum 10mm depth of cut with a 3mm wide kerf. This blade produces a slightly finer texture than the Mini-Industrial blade, which produces a 4mm wide kerf.

I use both blades for Fluid Texturing, as each produces a slightly different finished texture. On small items where I want a thin, delicate texture, I use the standard steel blade.

The Mini-Grinder utilises a 150mm extension arm, onto which 50mm cutting blades and accessories are fitted. These include the standard hardened steel blades (6 teeth- 40 degree Rockwell C), the Mini-Tungsten Carbide Industrial blade (2 teeth), a dry Mini-Diamond blade and Mini-Sanders in metric 40, 60, 80 and 120 grits.

Mini-Grinder fitted with the 50mm (2") Mini-Sander disk on a Bosch 1375-A angle grinder

Fluid Texturing using the Arbortech Industrial Carver

The larger Industrial Carver with its hollow-ground Tungsten Carbide cutters, mimic a traditional gouge cut. The Industrial Carver sports a precision-machined 100mm diameter blade that produces a 22mm maximum depth of cut, with a 8mm wide kerf. This wider kerf is very useful for Fluid Texturing larger areas, like the exterior walls of hollow forms. The blade features three K-40 grade Tungsten Carbide teeth. The specially designed teeth can be rotated when they eventually blunt, providing a freshly sharpened tooth edge. After all edges are eventually blunted, the cutters can be lapped on a diamond hone, or they can be easily replaced. This tool produces a very provocative, scalloped type of texture. It can create random scallops that appear hand cut, or more compacted designs that texture the entire surface of the turning. Depending on the presentation angle, speed and forward attack depth, numerous variants can be created.

Using the Pro-2 & Pro-3 Woodcarvers for Fluid Texturing

Pro-2 Carver 100mm (4") blade, fitted to a Bosch 1375-A angle grinder with Pro-Guard attached

The Arbortech Pro-2 and Pro-3 Woodcarver blades produce the same texture created by the Industrial Carver, however they require more frequent sharpening.

The Pro-2 Woodcarver blade is case hardened to 62 degree Rockwell C and is sharpened with an Aluminium Oxide sharpening stick, or power stick. The Pro-3 Woodcarver blade is hardened to 40 degree Rockwell C and is sharpened with a standard 1/4" rat-tail chainsaw file.

Types of Textures Created

Many different types of textures can be created with the various Mini-Grinder blades and by using the Industrial Carver blade. Clockwise, counter-clockwise and dual spirals can be easily created. Step back rings, alternating skip rings, fluid continuous sweeps, counter carved diamond sweeps, counter carved step back rings and many other textures are possible. Simply changing the speed of the work piece can create an infinite range of textures. In addition, the specific blade, angle of presentation, rotation direction and which side of the lathe you stand on will also affect the texture created.

Fluid Texturing End Grain

Much like chatter work, the highest quality textures are produced on dense end grain. The Mini-Grinder works best with the lathe running in reverse during most cutting operations. This presents an up turning timber meeting a down turning blade, creating the most efficient cutting action. The result is crisp, clean and well-burnished texture surfaces.

With advanced freehand techniques, unique endgrain textures can be created. I call one of these my Bimini Hut texture, because it reminds me of the Palm frond roofs on thatched huts.

This texture is created using the upper quadrant of the cutting blade on the Mini-Grinder. The tool is gently swept down and back, whilst the work piece is turning at 500 rpm, in reverse. A magnificent slow counter-clockwise spiral results, which is quite provocative.

"Bimini Hut" counter-clockwise, spiral diamond texture on end grain Pecan lamp base. The texture was sprayed with a flat black paint to enhance the piece

Fluid Texturing Side Grain

Side grain can also be successfully textured on many timbers. The denser species work best here as well, but softer species can be successfully textured with proper surface preparation. For softer timbers, you will need to stabilise the fibres in one of two ways. The first and simplest way is to simply flood the surface of the area to be textured, with a dilute Cellulose Sanding Sealer.

Pro-3 Carver 100mm (4") blade, fitted to a Bosch 1375-A angle grinder with Pro-Guard attached

I prefer to use Mylands Cellulose Sanding Sealer, which is diluted 50% with Cellulose thinners. This diluted mixture penetrates the fibres of the side grain very well and can be quickly friction dried. The Cellulose Sanding Sealer stiffens the side grain and allows it to be cut cleanly.

The second method is used on very soft timbers, or those that may contain “punky” areas. For these, I use a thin penetrating epoxy that will penetrate the fibres below the maximum depth of the intended texture.

Tips for Producing Clean Cuts

To produce the highest quality textures, you must have a freshly sharpened blade! Prior to fluid texturing an area, resharpen the standard metal blade on the Mini-Grinder with a small 4mm diameter rat-tail file. If you use the Mini-Industrial blade, hone the face of the cutter with a fine, or very fine diamond hone for best results.

When honing the Mini-Industrial blade, insure that the face of the Tungsten tooth remains flat and true. You do not want to introduce any negative rake on the face of the tooth. Two laps with the diamond hone are sufficient to touch up the edge of the cutter. When using the larger Industrial Carver, sharpening or honing is seldom required.

Step back clockwise ring texture on an end grain Cocobolo box top

Mini-Grinder fitted with 50mm (2") standard steel blade on a Bosch 1375-A angle grinder

The best side grain fluid texturing results are obtained on relatively straight grained, dense stock. If there is too much wave, wild grain, or curl in the piece, you may experience side grain tear-out.

To combat this problem, increase the degree of presentation angle, or reverse your cutting direction. Much like traditional “static” carving, timber generally cuts best in one direction.

If you are experiencing difficulties like tear-out or fuzzy textures, reverse the cutting direction to improve the quality of the cut. Softer timbers may require grain stabilization with thin lacquer, or thin epoxies before Fluid Texturing. If you still experience tear out, the chosen timber may not be suitable for side grain FluidTexturing.

Fluid Texturing Box Tops

Boxes are typically turned end grain and therefore, present an end grain box top available for texturing. The Mini-Grinder excels at end grain Fluid Texturing and the speed and quality of the cut is nothing short of spectacular. Its small size allows it to texture in very tight or restricted areas with relative ease. The Tungsten Carbide cutter and the standard cutter on the Mini-Grinder both work well, although the Tungsten cutter offers a bit more control on very dense timbers.

Suitable Timbers for Fluid Texturing

Any dense timber will produce excellent textures. The harder exotic species work best, but many other species can also be successfully textured.

I have achieved excellent results with the following timbers: Pecan, Mesquite, Box Elder, White Ash, Black Ash, Black Walnut, Hard Maple, Cocobolo, Palissander, Nigerian Ebony, Desert Ironwood, Leadwood, Tulipwood, Kingwood, Honduras Rosewood, Mexican Rosewood, Lignum Vitae, Texas Ebony, Guyacan and Pink Ivory.

When the grain was properly stabilised before Fluid Texturing, the following softer timbers produced very good results: Poplar, Sweet Gum and Soft Maple.

Mini-Grinder fitted with the 50mm (2") dry Mini-Diamond blade on a Bosch 1375-A anle grinder. This blade can be used to sculpt and cut concrete, marble and many types of stone

Fluid Texturing, Step-by-Step

There are six variables that determine what your texture will look like:

  1. Direction of rotation
  2. Lathe speed
  3. Presentation angle
  4. Penetration depth
  5. Which side of the lathe you stand on
  6. Firmness of your handgrip

The direction of rotation for end grain Fluid Texturing is typically in reverse, but forward rotations can be used on denser timbers with very good results. On side grain Fluid Texturing, forward, or reverse rotations can be used with equal success. The speed of the lathe is critical. Most textures are created between 300 and 1800 revs. Slower revs yield textures that look more hand cut. Faster revs yield a more machined look. Revs above 1800, tend to obliterate the texture.

The presentation angle determines what angle the texture will have and to a large degree, the overall visual impression of the texture. You can texture at any angle from 0 degrees to 90 degrees. However, in practice you are limited to an 88-degree window. If you hold either of the tools at 90 degrees to the surface of the timber, you will only cut a 3mm - 8mm cove, depending on the specific blade used.

When you begin to come off 90 degrees, the pattern expands and begins to create the textures. Most of the end grain textures are created between 5 and 45 degrees. Side grain textures are typically created between 45 and 180 degrees. The penetration depth controls the aggressiveness of the texture. If you want a soft, delicate texture, you lightly touch the tool to the timber. If you want a more aggressive look, simply advance the cutter a bit deeper into the timber. This will create deeper, more robust textures. Which side of the lathe you stand on also plays an important role in the look of the finished textures.

If you want to create a double diamond cut, you begin your Fluid Texturing standing on the front of the lathe. Then, you step to the rear of the lathe and reapply the texture over the previously textured surface. This gives a dual spiral-diamond cut that looks like two spirals, one clockwise and one counter clockwise and is quite provocative.

Simply reversing the lathe and remaining on the front side will not accomplish this. You must utilize both sides of the lathe to create this advanced texture. Lastly, the firmness of your grip plays an important role as well. Most precision textures require a firm grip on the tool. However, a slightly relaxed grip will allow the tip of the tool to chatter a bit on the surface, creating an alternating skip texture.

Pecan crotch platter rim prepared for texturing with the Mini-Grinder. The center section is left unturned to stabilize the outer rim during texturing. Upon completion of texturing, the inner portion is finished

When you first begin to create Fluid Textures, you may wish to use the tool rest to help stabilize the tool. This is particularly useful whilst using the Mini-Grinder, with its 150mm extension arm. If you choose to use your tool rest to help stabilize the tool for Fluid Texturing, be careful when removing the tool from the rest.

The first Step Back ring is completed using the freehand technique. All rings are textured from the center, towards the outer rim

Let the spinning blade come to a full stop, before you remove the tool from the tool rest, or set the tool down on the lathe. The blades can easily cut the lathe’s tool rest, or bedway.

As you progress in your skills, you may wish to try freehand Fluid Texturing. Freehand Fluid Texturing allows more creativity in the textures produced, but it’s difficult to master.

Creating a Standard Step Back Ring Texture

Tool: Mini-Grinder outfitted with standard metal blade, or Mini-Tungsten Carbide blade.

Speed and Direction of Rotation: 500-revs, reverse.

Presentation Angle: 45 degrees

Penetration Depth: Very light

Handgrip: Firm

Spiral Produced: Clockwise

To create my Step Back ring texture, set your lathe revs to 500 and your rotation to reverse. Turn on the Mini-Grinder and slowly advance the spinning blade towards the subject area. Since this formula creates a delicate texture, you want to lightly touch the spinning timber with the end of the blade.

Third and final Step Back
ring is completed

The second Step Back
ring is completed

Then, carefully withdraw the blade and move back a bit to create the next ring. Repeat this until the area has been completely textured. When you have completed all of the necessary rings, stop the lathe and observe the texture. A blast of high-pressure air easily removes any dust from the textured area.

If you do not have an air supply in your studio, you can use a stiff bristle brass brush. If you would like to burnish the textured area bit, you can set your lathe to 300 revs and lightly run the brass brush over the area for a few seconds.

This process is extremely fast and produces a very high quality cut surface. A 75mm box top can be textured in three seconds. If you texture the side grain as well, it will only take six to eight seconds longer for a box that is 150mm tall.

Variations on the Step Back Ring: To create an uninterrupted Continuous Spiral, simply draw the tool back in one slow sweep. To create the Alternating Skip texture, relax your handhold a wee bit and allow the tool to chatter lightly on the surface as it cuts. Very subtle and provocative textures can be obtained when the right combination of speed, presentation angle and rotation are observed.

Creating the Bimini-Hut Texture

Tool: Mini-Grinder outfitted with standard metal blade, or Mini-Tungsten carbide blade.
Speed and Direction of Rotation: 500-revs, reverse.
Presentation Angle: 65 degrees
Penetration Depth: Moderate
Handgrip: Firm
Spiral Produced: Counter-Clockwise

This is an advanced freehand texture, which has been very popular with turners at my demonstrations around the United States. To create this texture, set your lathe revs to 500 and the direction of rotation to reverse. Turn the Mini-Grinder on and advance the tool towards the subject area. You will be using the upper quadrant of the blade. As the tool contacts the timber, sweep it down and back with light pressure.

Once the initial cuts have been made, increase the forward pressure slightly and allow the tool to completely cut the surface of the timber. You must continue to sweep the tool down and back, until you have reached the desired depth of penetration. Stop the lathe and examine the texture. Remove the surface dust and gently burnish the texture with a brass brush if necessary. This texture is best suited to dense end grain timbers that are still relatively green, but it can also be achieved on some dry timbers.

I hope this article will encourage you to stretch your creative boundaries and experiment with Fluid Texturing. I have only begun to scratch the surface of what can be accomplished. In my studio work, I have created over two-dozen different Fluid Texture “recipes”.

Each one is unique and can add a significant visual presence to an otherwise simple and graceful turning. Make notes of the textures you create, so they can be easily repeated in the future.

Clockwise step-back ring

Safety Note: Please observe all manufacturer fitting and usage instructions when using any of the Arbortech tools. Never operate these tools without the proper safety attachments, including the clear polycarbonate Pro-Guard shield where applicable.

The high speed, noise and dust created by these grinder units require the user to wear proper hearing protection, respiratory protection and eye/full-face protection. In addition, the auxiliary grinder handle should be installed and used for additional tool control.

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.