Sixteen years and change ago, we moved to our current location in Naperville, Illinois. As a house warming gift, Uncle Ray Lauderbach gave us an illuminated house number sign. He had made many of these for his neighbors in New Jersey. The design consisted of a wooden box about 5″ x 12″, and 3″ deep. It’s assembled using box (finger) joints. There is a groove around the front where the number template, cut from thin black foam and glued to a sheet of textured plastic sits, along with a sheet of thin plastic as a front face plate. The back of the box is a sheet cut from a plastic mirror tile. Ray installed three 12 volt incandescent bulbs connected in series, these were powered by a 20 VAC wall wart, the undervoltage provided a dim but long lived illumination.
I screwed the box to the front of our garage.
I’ve painted the box four times and caulked the face plate but could not keep moisture out of the interior. In 2015 I could see the corners crumbling and it was clear that reconstruction was necessary. I removed it from the garage and disassembled. It’s a credit to Uncle Rays box jointing skills that I had to jack the ends apart with a reversed clamp to extract the number stencil sandwich from it’s groove. I cleaned everything and prepared to make a new wooden box.
Home Depot has these half inch thick Cedar fence pickets 6 inches wide and four feet long. I made a bird house out of them a few years ago and its held up well. There were three pickets lounging in my lumber stash, so this was a logical starting point. Also in this photo you can see the number sandwich and the mirrored backing plate with the electrics.
I decided to use the “Eleven Grooved Box” technique with mitered corners reinforced with splines. So I ripped the picket to 3 inches, and cross cut to about 38 inches. This was clamped in my planing board, planed smooth on one side, and readied to cut a quarter inch groove the whole length.
I have a beautiful, genuinely old plow plane and used it to cut the groove. I’m sure the plow plane was quicker than setting up the router table, digging out the router, finding a bit, and creating a ton of sawdust. Note to self: Cedar shavings smell good and make good mulch.
This is a close up of the finished groove in what will be the front edge of the new box. The whole 38 inches has been grooved at this point.
A test showed that the number sandwich fit well in the quarter inch groove. Also in this picture you can see one corner of the old light box.
The next step in making an Eleven Grooved Box (actually this one only needs nine grooves) is to slice the stock into 45 degree mitered side pieces. This is done using a big Stanley miter box. I used the plastic front face plate to gauge the dimensions of the pieces, leaving about an eighth of an inch extra for caulking.
With all four sides cut and checked for equal length top to bottom and side to side, I could do a dry fit using a strap clamp with the number sandwich inserted. It worked perfectly.
Next to cut grooves in each of the eight miter faces to receive the eighth inch splines I had cut from the remaining piece of the Cedar picket. I have a jig for this, developed to hold a Stanley 45 plow plane in just the right orientation.
All four box sides have been grooved in this photo. The jig mentioned above allows a clean cut which means a tight fit for the splines that will be glued in.
The number sandwich has to be inserted in the front groove as the box is glued together. I made this a two step operation by gluing up the top, bottom, and one end only first, then inserting the plastic number sandwich, then finally gluing the last end in place. This photo was taken while the first stage was setting. The second end is in place to keep the box in shape, it has no glue applied yet.
I applied silicone sealant to the front edge only of the groove, inserted the plastic face plate, pressed it in place against the sealant, then slid in the number stencil with it’s textured plastic backing. This seals the front tightly but will allow the number itself to breathe a little bit.
Then glue was applied to the final box side piece along with it’s two splines, sealant applied as before, the final end inserted and clamped. The photo below was taken the rear surface planed flush and the box primed. You can see how the splines fit tightly and reinforce each corner. There is only a single joint line exposed to the weather.
At this point I fitted the rear mirror with it’s electrics to the box and tested under power. It did not light. I checked and every one of the three light bulbs were open. Apparently they did not survive the box disassembly. These were bayonet base 12 volt bulbs from Radio Shack. Radio Shack no longer exists in this area, so I decided rather than try to find replacements, to construct something with white LEDs.
On the table saw I ripped a strip from an old prototype printed circuit board. It has a single long row of tenth inch spacing holes. Note to self: wear safety glasses and use a carbide tipped blade you don’t care about. Fiberglass is very abrasive.
I have a handful of white LEDs harvested from a string I got during a post Christmas sale, and dug up a 12 volt wall wart (actually measured closer to 18 volts). I soldered eight LEDs to the PC strip, wiring them in pairs with a 1500 ohm resistor between each pair which allows about 10 milliamps. Each pair is wired to common power points in the center. I splayed alternate LEDs out a bit to spread the light more evenly.
I removed the old bulb sockets from the mirror but left the three supporting copper brackets. With a bit of bending I was able to solder the new LED strip to the copper strips for good support. The LEDs point towards the mirror, not towards the front. I felt this would spread the light more evenly.
A dry fit in the box showed good even illumination. There is a slight shadow across the center due to the PC board strip but hardly noticeable.
Back in the garage, I reattached the strip of flashing across the top rear that mounted the old box. Then I attached a strip of extruded aluminum behind the flashing. This will tilt the box forward slightly and help rain to run off. I cut a small piece of flashing and attached to the bottom of the box to make sure that edge is held tightly against the wall.
Here is the front view of the rebuilt box after a couple coats of paint. Note to self: paint doesn’t stick to silicone sealant fingerprints.
So now it’s show time. Screw the creation back on the garage face. Since I used the original rear plate and mounting bracket, I only had to drill one new pilot hole. The power wire was routed inside across the header plate to the nearest outlet and stapled down. Power is on continuously, you can’t see the illumination in the daylight but because of Uncle Ray’s black background the numbers are very readable.
Finally the real test, how does it work at night? It’s a little bit brighter than the original setup but still not so bright it is distracting.
Thanks Uncle Ray!