Glass and Zinc Came Selections
Since we're looking to get the full arts & crafts flavor of this lamp, we kept our glass color and selection to a minimum. Rather than clutter up the geometrics of the lamp with a kaleidoscope-like scheme, only four colors were chosen.

All the glass is from the Kokomo Glass Company:

• #1D-A solid white, flat opal used for trim and to border sections of the geometric pattern.
• #23D-Solid, caramel yellow opal with a soft matte-like finish; used in the largest expanses of glass on the long, side panels of the lamp.
• #32-Blue-green-amber mix, streaky, slightly translucent, flat glass; used in opposing bands set in from the edge of panels. This glass is the only multi-colored glass used in the lamp.
• #652-Translucent dark green. This almost cathedral looking glass is used in the outer large areas of the side panels, contrasting well with the lighter #32 glass. This color is brought back into the end panels along the center, angled glass sections. It is also used in the squares that dot the perimeter of all the panels.

Kokomo's glass was the perfect choice for this project. The softer, matte finish of their glass adds to the arts & crafts character of the lamp without having to resort to any fumbling or etching of either surface. Kokomo's glass also has good cutability. Given all the straight line cutting necessary for this design, and the fact that we were doing most of the cutting over a light table and against a straight edge, its ease of use was welcome. The only grinding we had to do was to remove any burns or flares along the cut edge. As we will shortly discuss, the fit of these lamp panels needs to be very tight, given the narrow profile of the Chicago metallic zinc came.

As you can see in the accompanying photo, the thinnest strips of Chicago Metallic zinc were used for the interior of the panels. This represents most of the surface area of the lamp. The hear of the zinc came is only 1/32" while the upper and lower flanges measure only 1/8" in diameter. With such tolerance, all cuts need to be accurate. If you like to hide rough cut edges of glass under the came's flange, forget it. This project would be a good place for you to cure yourself of a bad habit.

To achieve the tight fit, we used the outlines on the Prairie Design patterns as our guide. By making our cuts to either side of the outline, we were able to keep the spaces between our glass pieces uniform. We also test-fit all our pieces as they were cut too small or big.

For those readers unfamiliar with what's called the "English" method of glass cutting, let us briefly explain it. All of the cutting is done over an illuminated light table. Preferably, the light source is identical to the ultimately lighting the shade. In the case of most lamps, incandescent lighting is what's needed. Your layout or design, printed on either a relatively translucent sheet of paper or ideally, a clear sheet of acetate, is placed on the light table. The appropriate glass is then placed over its corresponding pattern in the design. If the light is sufficient, the layout paper or material not too dense, and of course your glass isn't a strong opaque, you should be able to see your cut, or pattern lines through he glass using the edges of the lines as your guide. Care must be taken that neither the pattern nor the glass shifts out of position while you're cutting.

We used a straight edge metal ruler as our guide in cutting the pieces of glass. To set the proper position of the glass cutter along the cut line, we first set the ruler along the design line and then placed the glass cutter's housing against the ruler edge. We were then able to see that the cutting wheel would travel along the inside of the design line. The cutter we used was a new Toyo TC-1.

Any pieces that were similar in shape and/or size were numbered and their corresponding locations on the design were also numbered to prevent any unnecessary headaches later on in the project.

With all the pieces cut, we set up to lead, or zinc-up the panels. You'll see that 1/2' square wood strip was set against the outer borders of the design as our stop molding. It was secured to our homasote table top by nailing through the molding and the table surface. We positioned so that he border zinc and the first rows of glass would be in a proper position; the edges of the first rows of glass would sit within the black outlines of the design.

Each length of zinc came was place in position, marked with a pencil for cutting, approximately 1/16" away from the edge of the glass, (1/16" is half the 1/8" diameter of the adjoining came) and cut our Jarmac zinc Cutting Saw. It is advisable to keep the joints as tight as possible. Given the thin profile of the zinc used for these panels, and the rigid geometric style of the design, any gaps would easily fill with glops of solder, creating unsightly corners.

As we progressed from the bottom of the panel to the top, each successive row, or section of glass was secured with horseshoe nails.

One caveat: because the Chicago Metallic zinc is so thin, you cannot exert much inward pressure against your finished areas. If you do, you stand the chance of having the whole thing explode (come apart) as a result. We know because it happened to us. Consequently, the entire panel up to that point had to be reset. At the completion of every section, we checked to make sure that none of the glass was shifting out of position or drifting short or long of the cut lines. If they did, adjustments were made, which usually meant grinding or recutting the culprit piece of glass.

Soldering to zinc, for those used to working with lead or copper foil is relatively easy. Of course, proper soldering technique is necessary for the best results. Unlike lead, zinc will not melt or burn away as easily in reaction to heat of the soldering iron. Because of this, it is possible to sweat solder a seamless bond at all the joints.

In our studio, we had an Inland Temptrol 100(TM) iron handy. It's not what we consider a "big boy's" iron, but it did the job well, allowing us to get a smooth, sweat bond quickly and easily. We also used Fry Metal's Classic Ultra Lead Free Solder and their Classic 100 Gel Flux.

Sweat Soldering requires that you heat the surface of the receiving metal before you apply the solder. By doing this, the solder is introduced to the heated metal at a temperature near or at its melting point. The metal soaks up the solder in such a way as to leave the joint area flat (seamless). If any irregularities remain on the solder joint, they can be filed or sanded smooth

All of the zinc joints were soldered, checked and then rechecked. In a project such as this, where many of the joints look alike, it is very easy to miss one or two, even after checking. It is a good idea to look each panel over a number of times before attempting to turn it over to solder the joints on the rear. The panel was then rinsed clean of dirt and flux and blotted dry with paper towels.

We did not, at this time secure any of the border zinc to the panel. In anticipation of having to angle the edge zinc during the assembly of the four finished panels, we left them off and marked them for each panel. We used the same techniques to assemble the matching side panel.

The end panels are assembled and soldered and cleaned in the same way. Again we were careful to allow the glass or the came shift in position either beyond or short of the cut lines. The edge lengths of zinc were left off these panels as well.

We're now ready to join the panels together, reinforce the structure and add any mounting hardware to the finished shade.

Finishing the Lamp
Once the four panels have been assembled, a few of the detailing techniques remain. These "details" give the panel assemblies smooth joints and clean edges. The Chicago Metallic zinc channel sections used to surround the four lamp panels were tack-soldered together, and then fill-soldered to strengthen the joints. To further improve the shade, we finished soldered both the inside and outside seams of the lamp with a low profile, recessed, flat bead, using a 150 watt iron, equipped with a 1/2" diameter chisel tip. The chisel tip allowed us to position one of the edges of the iron into a small "valley" or channel created between the zinc strips and gradually "float" a smooth bead of solder along their length. To do this properly, we had to maneuver the shade so that each line was soldered in a flat position. Attempting to solder an angled joint wouldn't work.

By carefully controlling the amount of 60/40 solder fed into the joints, we were able to achieve a recessed solder joint, one that did not fill the zinc joints to the top. Thus, the edges of the zinc strips remain in relief, adding to the architectural character of the shade.

To install the decorative perimeter of four sided Prairie zinc, we needed to cut and install brass spacers to the edges of the lamp, between the finished zinc edge and the decorative lengths. These spacers, cut from flat and 1/8" round brass scraps, were 1/2" in length and installed with the lamp flat on our worktable. The four sided zinc strips were then cut to size, their edges mitered to fit, and then soldered to the spacers. Care must be taken to get a substantial bond between the lamp itself, the spacers and the four sided zinc strips. Inevitably, the finished lamp will be handled from these edges. If they're not securely fastened to the shade, they will pull away.

Finally, two crossbars will have to be installed into the shade. They will support the lamp on the lighting fixtures of the bronze base. We will hold on their installation until the base is prepared.

Preparing the Bronze Base Chicago Art Glass, beside their quality art glass, produces a beautiful bronze reproduction of Frank Lloyd Wright's Double Pedestal Prairie Lamp Base. It's perfect for the Prairie Design of California shade. The base is cast in solid and channeled bronze, with all allowances for wiring, lighting fixtures and vertical glass panels built into the unit. The set up, which involves wiring the base more than anything else, is pretty straightforward, as you will see.

Step 1: You will need about twelve feet of standard lamp wire, two electrical connectors to splice the double fixtures together, some electrical tape, a wire clipper, two standard brass sockets, two six inch harps and finials and two ten inch crossbars with a 3/8' hole drilled in the center of each.

Step 2: Cut the vertical panels 6 11/16 X 10 1/4 out of Kokomo #32. They are then framed with 2702 Prairie Came channel. Be careful not to fill the ends of the channels with solder. They need to be left open, as you will see shortly. The vertical stanchions of the base can be removed from the bottom platform structure of the base by undoing the bolts hidden beneath the bottom bronze channel with a 1/4" allen wrench. Once removed, carefully position the framed glass panels with spaced end of the panel at the top. The base has a narrow groove incised where the lamp wire will fit. Cut the lamp wire into two lengths: one nine feet long, and the other three. Take the longer of the two and feed it through one of the drilled feed holes in the bottom of the base, through the vertical zinc channel, up along one of the base stanchions, halfway across the shorter, horizontal members and out through the drilled and tapped hole that will eventually secure the light socket and harp to the base. Do not attach the fixture at this time. Repeat this procedure on the second glass panel before replacing the two stanchions. At this point, you should have wire ends extending from top and bottom of the base. Be sure you have at least six inches of wire at the socket locations on the base, and that the shorter length meets the longer one at the bottom of the base with at least three inches of wire to spare. The two wires will be spliced together at this point. They can be made shorter, if necessary.

Step 3: We joined the wires in a simple dual splice, cutting, in effect three ends, one from the second stanchion, and one leading out from the bottom of the base platform. The six ends (three pairs) were stripped and carefully twist-spliced together making sure that the leads were not confused and that one length from each location eventually formed a single lead. The two resulting junctures were wrapped with electrical tape and capped with plastic, screw on electrical fastness. The under-channel of the base platform is deep enough to hide these connections.

Step 4: With the basic wiring complete, the sockets themselves can be installed. To do this, you will n need two 1/2" long 3/8' threaded nipples. One end of each nipple is screwed into the tapped holes at the top of the base where the wire extends. Thread the wire through the nipple as you screw it in. Bare the ends of the wires and attach them to the poles on the socket. Be sure your harp fastness are installed at the bottom of your sockets before going to the next step. The socket can then be screwed into the extending nipple end. Tightening will secure it and the harp fastener to the base. Install the harp fasteners and wire the socket.

The two crossbars are positioned by placing and tightening them onto the ends of the harps. Carefully fold the the finished shade over the base, marking an appropriate location on the inside of the shade where the ends of the crossbars meet a length of zinc on both sides of the lamp. Once marked, the crossbars are removed from the harps, cut to size and soldered into the shade. Be sure the solder joint is substantial; these crossbars will have to support the weight of the shade.

All of the construction is now complete. All that is needed now is to attach a plug to the end of your lamp wiring, install two light bulbs into your sockets, mount and secure the shade onto the base, turn it on and enjoy.