Schleifen kleiner Objekte
Before you work with Dopping-wax, please read the safety instructions at the end of this article.
Helper to grind small objects.
Often it is difficult to keep small cloisonné or Champlevé objects, such as brooches or pendants during the grinding, regardless of whether you grind by hand or with an electrical machine. Here you can use a technique of the gemstone-cutter. To hold small stones, the lapidary sticks these objects on a holder, the so-called dop stick. The dop stick is nothing more than a rod of wood or metal. The tip of the rod becomes covered with special glue called “Dopping Wax” (Picture right) and the stone becomes glued onto the dopping wax-prepared rod. Beside wooden or metal rods you can also all kind of handles or other suitable things use.
Dopping-wax is based on shellac-base, and although it melts at a low temperature it has a great holding ability. One can acquire it by lapidary-supplier via Internet. It becomes selling in different forms and colors. (Picture right). The colors are an indicator for the melting point of the wax. I myself use the yellow wax.
Preparing a dop stick.
Put up a small amount of the wax into a metal container or bowl. Heat up the container with a torch, or better onto an electrical cooking plate. Be very careful, not overheat the wax, because it is flammable! In the Internet you get also a special "Dop wac melter". (Pictue right)
Since it is important, that not only the wax is hot and molten but also the work piece is good warm, place the work piece onto a counter enamel wire net and this all together onto the cooking plate.
If the wax is molten, dunk the tip of a rod into the wax. (Pic left).
Take the warm work piece in the other hand, if necessary with leather gloves. Press the WP (work piece) with the back as soon as possible, on the stick with the hot wax. (Pic right). Hold it in this position for about 30 sec. Then the wax should be hard and the WP should well stick onto the dop-stick. The ensemble is ready for the grinding.
The once with doping wax coated stick can be used several times. For this purpose, the wax at the top of the dop-sticks either with the flame of a torch or of a spiritus burner (pic right) heated, until it is viscous. The also warmed-up workpiece is then immediately pressed against the wax surface and held for about 30 sec . The Ws should now adhere well to the stick. Be careful, the wax is highly inflammable.
So as I wrote, the wax has a great holding ability. But it is a bit sensitive against side-wise pressure. Therefore, if you want to grind a larger object, enlarge the "Tip" of the rod. Cut out a piece of metal sheet which is a bit smaller than the outer dimension of the WP. (Pic left). Drill a hole in the middle of the metal-sheet and screw the sheet onto the tip of a wooden rod. (Pic right). Dip the sheet into the molten wax and press the back of the up warmed work piece onto the dop stick sheet.
The dop stick fastening is especially suitable, if you have to grind very small items as for instance cufflinks or earring parts. A time ago I had a lot of about in silver rims fitted Millefiori to grind, which had a diameter of only 10 mm. If you have to hold such small items with your fingers, you grind your fingertips more and quicker, than the small items.
To remove the workpiece from the dop-stick, put the dop-stick + workpiece for 2-3 min. into deep freezer. The workpiece is easy to remove.
Grinding with electrical wet grinding machine
Start grinding with a diamond-belt of about 220-360 grit. Press the enamel surface only very light against the belt!! Grind very careful, because the abrasion is very quick. Appraise the surface of the WP all few seconds. If you all wires by cloisonné-pieces can see, or by champlevé the whole metal areas, change over to the next finer belt.
If you during the grinding see in the surface a shiny depression or a pore , clean the WP very well, grind the pore with a diamond-cutter, fill up the pit(s), dry and fire the piece again. Do not try to remove the pit by grinding!
Change the grit of the diamond belts, until you are pleased with the result. Then you can continue to work in two different steps.
Step 1) Flash firing. Clean the WP with a hard tooth- or nailbrush under running water. Dry it and fire it in a hot kiln (800-900 degree C). Observe the firing well. Remove the WP from the kiln, as soon as the enamel surface is smooth and shiny.
Step 2) Polishing to silk like gloss. If you do not want the high gloss flash-fired enamel surface, you can grind the enamel surface at last with a band of 1000 grit. After cleaning the WP change over to a wet felt wheel. The wheel becomes coated with "Cer-oxide", which you can buy via Lapidary-supplier. Polish the work piece, until you are pleased with the silk-like enamel surface. Brush the WP with a hard tooth- or nailbrush under running water. Dry it well. Warm it hand-hot up and wax it with a WHITE rest of a candle. Do not use colored wax, because the enamel surface could adopt the color. Afterwards polish the surface at first with a paper kitchen towel. If all the wax is nearly removed, polish the surface with the heel of your hand. The surface should a soft, silk-like surface have.
If all grinding and polishing is finished, place the stick + WP, so as written above, into the deep freezer. After a few minutes you can remove the WP from the stick very easy. During the WHOLE process the enamel do not suffer any damage..
There are some Videos in You Tube re dopping technique. Here the address of one video:
Dopping Gem Stones with Wax: http://www.youtube.com/watch?v=wEzKXdVjV2Y
Even if you grind with Carborundum Stones or Diamond pads with your hands, the dopping method can be helpful. Fasten on the back of the WP a "handle". It makes it easier to hold the work piece during the grinding process, especially if you have to grind small items like earring-pieces.
Make a small wooden brick, which is a bit smaller than the back of the WP. For a good hold, it should be about 2-3 cm thick. Fasten it with dopping wax as described before.
If you have to grind a flat work piece, lay the abrasive-paper onto a thin foam rubber sheet.