Dop Wax and Dopping: How to Mount Stones for Faceting

The Importance of Secure Dopping

In lapidary, particularly in faceting and cabochon cutting, "dopping" is the process of attaching a rough stone to a stick (the dop). This provides a secure, comfortable handle, allowing you to manipulate the stone against the grinding wheel or faceting lap with precision. If a stone shifts or falls off the dop during cutting, it can result in a ruined design, a chipped stone, or at the very least, hours of lost work trying to realign it. Mastering the use of dop wax and adhesives is an essential skill found in any lapidary's faceting accessories toolkit.

Types of Dop Wax: Brown, Green, and Black

Dop wax is a specialized shellac-based resin designed to hold stones securely when cool but melt at relatively low temperatures for easy application and removal. It comes in three main varieties, color-coded by their melting points and holding strength.

Green Dop Wax (Low Temperature): Melting around 150°F (65°C), green wax is designed for heat-sensitive stones like opal, turquoise, and fluorite. Because it melts at a lower temperature, it prevents thermal shock that could crack delicate gems. However, it is the softest of the waxes and can shift if the stone gets too warm from grinding friction.

Brown Dop Wax (Medium Temperature): Melting around 160°F to 170°F, brown wax is the standard, all-purpose workhorse for cabochon cutting. It holds securely for most quartz family stones (agate, jasper, amethyst) and is relatively easy to work with.

Black Dop Wax (High Temperature): Melting around 175°F or higher, black wax is extremely hard and brittle. It is primarily used in faceting, where absolute rigidity is required to cut perfectly flat facets. It is suitable for hard, heat-tolerant stones like sapphire, garnet, and topaz.

The Wax Dopping Process

Dopping with wax requires careful temperature control. You will need a heat source, such as an alcohol lamp, a specialized dopping pot, or an electric hot plate.

1. Prepare the Stone: The stone must be absolutely clean, dry, and slightly warmed. Wax will not stick to a cold or wet stone. Place the stone near the heat source to warm it gently.
2. Prepare the Dop Stick: Heat the brass or wooden dop stick and melt a small glob of wax onto the tip.
3. Join and Shape: Briefly pass the wax on the stick and the back of the warmed stone through the alcohol flame to ensure both surfaces are tacky. Press the stick firmly onto the center of the stone. Wet your fingers and mold the warm wax around the base of the stone to create a secure, fluted cone.
4. Cooling: Allow the stone to air cool completely. Never plunge a hot, dopped stone into cold water, as the thermal shock will crack it instantly.

Super Glue (Cyanoacrylate) Dopping

Many modern faceters and cab cutters have moved away from wax entirely, preferring the convenience of Cyanoacrylate (CA) super glue, often combined with a two-part epoxy. This method requires no heat, completely eliminating the risk of thermal shock to valuable rough.

To dop with CA glue, ensure the stone is flat and clean. Apply a drop of thick gel-style CA glue to the flat brass dop, press it onto the stone, and hold it perfectly still for a minute. Many cutters use a CA accelerator spray to cure the glue instantly. The downside to CA glue is that it can release if the stone gets wet and warm for extended periods, though this is rarely an issue in modern wet-cutting setups.

Choosing Dop Sticks

For cabochon cutting, simple wooden dowels (1/4" to 3/8" diameter) are cheap, effective, and insulate your fingers from cold water. In faceting, precision is paramount, so machined brass or aluminum dops are used. These come in various sizes and shapes (flat, cone, V-groove) to perfectly match the shape of the pavilion or crown being cut.

Transfer Techniques and Removal

In faceting, once the bottom of the stone (pavilion) is cut, it must be transferred to a new dop perfectly aligned on its axis to cut the top (crown). This is done using a precision transfer jig. The new dop is glued or waxed to the cut pavilion, and then the original dop is removed from the flat top.

To remove a stone dopped with wax, you can gently heat the dop stick (not the stone) until the wax softens, or place the entire assembly in the freezer for ten minutes; the cold causes the wax to become brittle and it will often pop off with a gentle tap. To remove a stone dopped with CA glue, soak it in acetone or apply gentle heat with a torch to break the glue bond.