Wednesday, November 21, 2012

How To: Silver Reticulation With A Weed Burner.

RETICULATED SILVER

This is a great way to achieve natural spontaneous looking textures on silver. In this example, I’m using 22 gage, 80/20 “coin silver”, 1-1/2 by 4-1/2 inches. Sterling silver may also be used. However, coin silver has a lower melting point and lends itself better to the reticulation process. I’m also using a weed burner in this example. The weed burner has a large flame and it can be used to heat the whole piece more or less simultaneously, which helps prevent melting holes through the sheet and/or uneven or unattractive patterns, which is often the case when using a small pencil flame. The weed burner is especially helpful on relatively large pieces.

#1. The first step is called “depletion silvering”, which is the same process as depletion gilding only on silver instead of gold. The piece (or pieces) are heated with the torch until they oxidize and turn black. It is then quenched and pickled in a crock pot. The pickling solution (sodium bisulfate and water) removes the copper oxide from the surface of the silver.

#2. After this process of heating and pickling is repeated several times, the copper or cupric oxide begins to be leached away from the surface of the silver leaving a thin film or “skin” of pure silver on the surface.

#3. The process of heating and pickling is repeated until the surface no longer oxidizes and appears a “frosty white” color. For good measure repeat the depletion silvering process 2-3 more times. The total number of cycles is usually around 10-12 times. Since the pure silver skin melts at a higher temperature than the copper/silver alloy core, the sheet will “reticulate“ and buckle when heated to the melting point of the core alloy. Place the sheet on a fire brick or other suitable ceramic refractory surface. Heat the sheet with the weed burner until the reticulated texture develops.

#4.After this is accomplished, pickle and clean the surface of the piece with a wire brush and/or steel wool.

Detail of a reticulated silver and bronze knife handle.

Double (twice) reticulated silver cross pendant.

More on silver reticulation, CLICK HERE.

Monday, November 12, 2012

How To: Fabricating An End Cap For A Knife Handle.

The end cap, sometimes called a “butt cap”, serves to protect the end of the handle from impact and acts as a “ferrule” to help prevent the handle from ever splitting. In this scenario, it also serves to conceal a counter sunk nut on the end of a threaded tang.

In this example I’m using bronze.

#1. This is a two part fabrication, a brazed oval ring with a good friction fit to the end of the handle and a swedged plate, Approximately 1/8 inch thick, with a slight dome.

#2. Mark a line with a scribe around the inside of the hole and trim the swedged plate to the line at a slight angle with a grinder or a file. The taper will help achieve a snug fit and prevent the piece from slipping or sinking during silver brazing.

#3. Tap the piece into position with a hammer.

#4. Silver braze the piece in place.

#5. Pickle the end cap after brazing, clean up with files and sandpaper and check the fit.

At final assembly the end cap can be secured into place with a good high strength epoxy paste like J-B Weld. Since the end cap fits over the end of the handle mechanically with a nice tight friction fit, unlike a standard butt seam, it can’t be pulled, sheared or knocked off once the epoxy sets.