When AJM asked me to test the new 3M FX Polishing Wheels, I was reminded of a neat factoid: The House of Fabergé didn’t have the fancy technologies – laser welders, CAD/CAM, etc. – we have today, yet the objects of art they produced are in collections and museums worldwide. Think-ing of this, I wondered if these new polishing wheels would really outshine the more basic tools on my bench. I decided to find out.
|Photo courtesy of Gesswein|
Approximately one inch wide, green, and spongy, the 3M wheels arrived at my shop in 240, 800, and 3,000 grit. (They are also available in 320, 600, and 1,500 grit.) Comprising silicone carbide mineral, the wheels are available in 4 inch, 6 inch, 8 inch, and 12 inch diameters. An adaptor, which is sold separately, can be inserted into the tube that runs through the center of the wheel and then threaded on the tapered spindle of a polishing motor. This makes it very easy to change wheels.
My first impression of the wheels was that they provided a controllable and consistent finish. Because they are soft, they conform to the shape of the object being buffed. 3M developed a cell technology that allows the wheels to follow curves and contours unlike anything I have used before.
When I read in the 3M literature that the wheels are designed to eliminate or reduce a jeweler’s need for buffs and compounds, I was skeptical, so I decided to give them a whirl on my buffer.
I use a Baldor buffing motor with a single speed of 3,450 rpm. 3M recommends using the FX wheels with a two-speed motor set on the slower setting, 1,800 rpm. It’s still possible to use them with a faster motor, but you need to use a little more water with the wheels. That’s right, water! Unlike other popular polishing products, such as the compound Tripoli, the FX wheels don’t remove metal, they burnish it. Burnishing actually moves the metal to cover file marks and scratches.
Since the wheels can be used wet or dry, it’s advisable to dip the jewelry piece in water to cool it off if it gets hot, and then put it back on the wheel wet. 3M suggests using very light pressure when burnishing; you should let the wheel do the work. But no matter how soft you push on the jewelry object, burnishing is bound to create heat, so the fact that the wheels can be run wet is a true benefit.
While using the 240, 800, and 3,000 grit wheels, it became clear that they are quite soft. I experimented with a 2 mm wide lady’s ring that I had just sized down. After filing the ring, I went directly to the 240 wheel. Failing to follow 3M’s advice about using light pressure, I dug a furrow in the wheel and the ring heated up quickly. After letting it cool for a few seconds, I inspected the ring and found that most of the file marks had been removed, not just in the center of the shank, but also on the sides. It appears that the wheel’s ability to contour to the jewelry piece made the operation go much faster than with a traditional polishing buff.
Learning my lesson from using too much pressure, I worked with the 800 and 3,000 grit wheels more carefully and found that they worked well. Other jewelers I know who have tried the wheels at lower speeds have had even greater success, with one jeweler attesting to the 240 grit wheel’s ability to burnish away microporosity. I didn’t have any pieces with microporosity, so I can neither confirm nor deny this claim.
With my best efforts, I achieved a finish slightly better than a Tripoli finish. After a run with the wheels, the jewelry still needed a final hit on a regular buff with the appropriate rouge, depending on the alloy.
Personally, I wouldn’t use the wheels for everyday repairs, as they are rather expensive ($23.04 for the 4 inch wheels). You need at least three wheels of varying grades to start, and more if you work with platinum. Since they are soft, they will not last forever, especially if you press hard into them
That said, I believe the wheels are excellent for pre-polishing platinum. They may eliminate the need for tedious hand sanding through progressive grits of emery paper. I also think they could be a big time saver when polishing small production runs of rough castings. Moreover, the ability to burnish microporosity quickly should earn them a place in every jeweler’s arsenal of polishing tricks.
When considering price, it’s important to remember the added value this product provides, such as greater precious metal retention and the reduction of Tripoli compounding steps. We stress that using moderate to light pressure will prolong the life of the product.