Overview:

While its electrical system is perhaps not the most glamorous aspect of the SBD's restoration, completing it successfully is, none-the-less, a vital aspect of returning the dive-bomber to flying condition. Pioneer's Doug Brown began the process of restoring the numerous electrical junction boxes which proliferate the airframe due the late summer, as described in Update 91. The present article covers the work he has completed during the interim.

Four of the replacement electrical junction boxes are seen here part way through their remanufacture. While some boxes feature the same external dimensions, each has a unique hole pattern. Each of the larger holes in these boxes will be filled by an electrical conduit fitting. Note that several additional, partly-completed junction boxes are visible in the background. (image via Pioneer Aero Ltd.)
Four of the replacement electrical junction boxes are seen here part way through their remanufacture. While some boxes feature the same external dimensions, each has a unique hole pattern. Each of the larger holes in these boxes will be filled by an electrical conduit fitting. Note that several additional, partly-completed junction boxes are visible in the background. (image via Pioneer Aero Ltd.)

Junction Box Remanufacture:

As discussed in the previous article, many of B-22's original electrical junction boxes required remanufacture due to corrosion damage. As a result, Pioneer's Doug Brown set up a mini-production line to refabricate them. While several boxes have nearly identical exterior dimensions, each has a different cluster of electrical entry ports cut into its sides making it unique. A number of boxes also have lids with unique sets of holes cut into them; entry points for mounting various switches and control knobs, depending upon a unit's function. Many of those holes feature descriptive signage beside them for outlining the function and operation of the switch or knob concerned. While the original lid would have had this etched into the aluminum surface chemically via a photolithographic process, Pioneer has chosen to inscribe these details with a CNC router instead—a more economic method for one-off parts. The following images show some of the current progress.

Another view of the replacement electrical junction boxes pictured in the previous image. Despite frequent similarities, no two boxes are exactly the same. Note that the small holes arrayed around the top lip of each box will have anchor nut assemblies installed in them for securing the lid. (image via Pioneer Aero Ltd.)
Another view of the replacement electrical junction boxes pictured in the previous image. Despite frequent similarities, no two boxes are exactly the same. Note that the small holes arrayed around the top lip of each box will have anchor nut assemblies installed in them for securing the lid. (image via Pioneer Aero Ltd.)

A third view of the electrical junction boxes. The small holes seen in the base of each box will serve as anchor points for mounting it to the airframe. Note the tags wired to each box—these have part identification numbers scribed into them to help Pioneer’s engineers keep track of what they have fabricated. (image via Pioneer Aero Ltd.)

A close up view showing one of the electrical junction boxes and the holes cut into it which will eventually filled with multi-pin plug sockets. (image via Pioneer Aero Ltd.)

The original lid (at top) from the lighting switch panel mounted within B-22's rear cockpit. This panel featured a range of switches and knobs for controlling each cockpit light. Note the signage inscribed below each switch position designating both a given light’s role and how to increase/reduce its illumination levels. Sadly, after bead blasting, the lid proved too corroded for airworthy use (note the pitting on the hinge for the flip cover). Below the original lid we can see its replacement (still in sheet form) in the process of being refabricated. The holes for mounting each control knob, along with their associated signage, have been cut into the surface, but the rest of the lid has yet to be shaped and trimmed to size. (image via Pioneer Aero Ltd.)

A closeup view of the original lid seen in the previous image—significant corrosion being evident. This shot shows the signage in greater detail. Typically, the lids were painted black, while the etched signage was filled with a luminescent paint (sometimes radium-based) to make it more easily visible in a darkened cockpit. (image via Pioneer Aero Ltd.)

A close up of the replacement lid for the rear cockpit lighting switch panel. The switch positions and engravings have already been made, but the panel has yet to be trimmed to size or have its edges shaped. Once the lid is trimmed to size, Doug Brown will place the flat panel on a specially-made forming block and roll the edges in to their correct shape. (image via Pioneer Aero Ltd.)

Each of the electrical junction boxes has a lid, with some of these having switches mounted onto them. Descriptions of the switch’s role and operation are etched beside the mounting point. Doug Brown recreated this signage by engraving the lids with a CNC router and cutting in the mounting holes into an oversized sheet of aluminum. With that completed, he then trimmed the lid to size and rolled the edges to the correct profile. This particular lid is fitted to the gun camera switch box; the original, corroded part from B-22 being seen here next to a partially completed reproduction. As should be obvious, corrosion damage rendered the original part beyond airworthy salvage. (image via Pioneer Aero Ltd.)
Each of the electrical junction boxes has a lid, with some of these having switches mounted onto them. Descriptions of the switch’s role and operation are etched beside the mounting point. Doug Brown recreated this signage by engraving the lids with a CNC router and cutting in the mounting holes into an oversized sheet of aluminum. With that completed, he then trimmed the lid to size and rolled the edges to the correct profile. This particular lid is fitted to the gun camera switch box; the original, corroded part from B-22 being seen here next to a partially completed reproduction. As should be obvious, corrosion damage rendered the original part beyond airworthy salvage. (image via Pioneer Aero Ltd.)