Sanding Sticks

Sanding the inside of hollow form and narrow opening vessels is quite difficult and for that reason, some say that the inside should not be sanded, only finished as best you can with your cutting tool of choice. However, on numerous occasions the inside needs to be sanded especially if you are going to carve the piece and reveal part or all of the inside or if the inside is accessible. Besides, a customer with a modest degree of turning sophistication will surely give it the old finger check. I like the surprised look when customers find a smooth finish inside my work. And, yes, sometimes I only sand down as far as my finger can reach.

Several options were explored for achieving a suitable finish; forceps, fingers with double sticky tape and sandpaper, light scraping, inertia sanders, and flap wheels were all tried but fell short of the practical, and safe, tool I wanted. Forceps were the best option but they were limited to a very small area and were far too slow. A set of pinchers to hold a sanding pad offered a potential solution and after several attempts, Sanding Sticks evolved.

With a set of straight and curved sticks you can reach almost any interior surface. They can be made much smaller or larger if needed. The drawing is for an average size that will cover most needs but you must turn an opening about 1 1/2" (or larger) in diameter.

Getting started: Prepare two 1/2" by 1" by 12" to 14" long sticks for the straight set of sticks. The stock for the curved jaw unit can be made from a 1/2" by 3" by 16" board. Locate the the jaw on either end and band saw the two pieces. Angle the curved jaws about 30 degrees from the center line. Use a fairly strong hardwood, (i.e. Maple, Walnut, Ash, Hickory) and, using some copy paper, glue them together with a thin coat of good wood glue on each stick. Newspaper is too thin these days (hard to part), hot melt too messy, and double sticky tape tends to come loose at high spindle speeds (don't ask how I know this).

Select a wood with strong cross grain strength for the cap and snap ring. My two favorites are Boxwood and Bradford Pear. There is little pressure on the end cap but the snap ring must be strong. Any wood that splits easily is not suitable. You will need a blank about 3" long and 1 1/2" in diameter for each set of sticks (1).

Predrill or ream a tapered hole in the glued together sticks for the tail stock and the driver. This will keep the point from separating the two pieces. Mount and turn to 7/8" diameter. I used a wrench as a gage (2). The diameter is not critical because you can fit the snap ring to the diameter you turn.

Layout the snap ridges starting about 3 1/2" from the end (3). Six rings works about right but a couple more is OK. Cut the ridges down to about 1/16" to 1/32", tapering away from the jaws end of the stick (4). I turn my bowl gouge on its side and use it as a skew to smooth the tapers (4A).

The narrow area between the snaprings and the bulge near the end cap is the position for the snap ring when changing sandpaper. It allows the jaws to open while inserting sanding pads. Leave the bulge as large as possible; it keeps the snapring from sliding too far back. Finish turning to the approximate dimensions shown on the drawing. After sanding (5), part or saw off the waste material and finish sanding by hand.

The curved set of sticks are made similarly but the curved jaws must be band-sawed or other wise formed(6). The max diameter must be small enough to allow the snap ring to slide on after the barbs are installed (~1/8" allowance or about 5/8" diameter). A carbide burr works great for preliminary shaping (7) and a cabinet scraper followed by sanding finishes the job.

Part the sticks and sand or scrape them clean on the inside (8). Using a belt sander or carving, taper the ends to about 30 degrees. The ends must also have their sides rounded so that when they are mated they fit into the cap (11) and when the jaws are brought together the turned lip inside the cap locks them together. A simple ring of wood or steel will also work but I like the look of a turned cap.

Chuck your cap/ring blank. Measure the diameter of the two shaped ends while the stick ends are held together (jaws are widely separated). This is the size hole you will need to insert the ends into the cap. Hollow the cap until the ends fit inside the cap and the jaws can be brought together (11). Finish turning the cap and part from the blank (12).

Measure the diameter of the sanding stick ridges. Add about .01" to .02" to this dimension for the snapring's small interior diameter. If you have a drill slightly smaller or exactly the right size, drill a hole about 1 1/4" deep. If the drill is undersized, hollow the inside to your previously measured diameter. I used a square end scraping tool to make this cut (14).

Next, increase the diameter by about 1/16" deep and leave a shoulder about 3/4" inside the ring (15). This edge will snap into the grooves and hold the sanding pad in place when it is pushed toward the jaws.

Finish turning the outside of the snapring (16). Your ring should have about 3/16" to 1/4" walls. Part the one inch long snapring from your blank (17).

Try the fit over your sticks. It should slip easily to the end. If the fit is too tight, turn a jam chuck and resize the small diameter interior to fit.

The barbs are made from 1" long brads or other small finishing nails (black arrow, 18) cut to about 3/16" long. They are just slightly over 0.05" in diameter. I used a 0.05" diameter bit in a Dremel tool to bore the holes. The cut ends were then jammed into the drilled holes. The holes are about 1/2" from the end and about 3/4" apart. The barbs should stick up about 1/16". The barbs could also be set in epoxy or CA. Assemble the cap, sticks, and snap ring.

Cut some sanding pads about 2" to 3" long, 1/2" thick, and about 1" wide. The material can be any rubber like material; I used a piece of interlocking floor mats. Cut a bunch of pads and have one ready for each grit. Wrap good quality sandpaper around the pad and insert it between the jaws. Push the snapring toward the jaws until it firmly grips the pad.

When using the sanding sticks, always remember to let the vessel wood “pull" the sandpaper. It will surely kick back if you try to push the pad into the work. Or put another way, sand in tension.

Using a stroking motion (back and forth while rotating slightly) will use more of the sanding surface and reduce clogging. Normally when sanding inside a hollow form, I will count the number of strokes--30 to 50 will generally produce a good surface ready for the next grit. Most of the time I start with 150 grit and work up to 320 grit.

I believe you will find Sanding Sticks a useful tool. After you have made a couple for yourself, constructing several more will go very quickly. Make a few sets for your turning friends.