The wall switches are all fed from a single 15A circuit. Looking back I wish I had given consideration to just how much juice the room will need. Turns out it is way more than 15A. Take a look at the power requirements just for lighting:

The total amperage for the entire arrangement is 41.9 amps. That is a whopping 4,818 watts of electricity! Fortunately, rarely will it all be on at once. Only during a full fledged operating session will all of the layout lights be on and then the room lighting won’t be needed. When I am working on the railroad I will need to turn on just the room lights and the layout lighting in the area where I am working. Thank goodness. I would need a second job to pay the electric bill if all the lights were all on a lot.

As you can see there is no way to power all of the lighting from my single 15A circuit presently installed. I have a solution however. First, there is one last open breaker spot left in the load center. I will pull a fresh 20A circuit from that spot. Second, there is an existing 20A circuit dedicated to the jet tub in the master bath. The bathroom is directly above the train room so the wiring crosses through the floor joists above the layout. A jet tub is cool and all but we rarely use it. I am going to put a junction box in the tub circuit so I can tap in. The layout lights can’t be on when the jet tub is running but no big deal. The jet tub has been used less than 10 times in all the time we have lived here so coordinating between use of the tub and lighting the layout should be no problem whatsoever. This combination provides me with two clean 20A circuits and the existing 15A circuit. All total that is 55A which when de-rated 20% for continuous duty equals 44A. Sweet!

Even if I can’t turn on all the layout lighting from the wall switch I still want to be able to at least turn off all the layout lights with the wall switch. For that I have come up with a solution.

* Everything inside the dotted rectangle is replicated for each of the load circuits in the table above except for room lighting

This circuit uses momentary contact push buttons and DPST relays to turn on/off each individual leg of the lighting circuits. The relay coils are powered by the existing wall switch circuit (which also powers room lighting) while the relay load contacts are powered by the 20A circuits. Turning on wall switch #2 will “arm” the push buttons. Depressing the ON push button will energize the coil. One set of contacts is wired so as to keep the relay coil energized after the push button is released. In effect it is a do-it-yourself latching relay. Turning off the wall switch will cause the relay to de-energize and the contacts will open. Now I can flip the wall switch on the way out and all layout lighting will go out. There is an OFF push button so I can, if desired, turn off sections of lighting without turning everything off and back on again.

Digikey has the relays I need in stock and a huge selection of decorative push button switches of sufficient rating. I plan to make a nice looking back-lit acrylic switch panel with labeling and put it on the lighting valance near the train room door. Walk in, flip the wall switch, push the buttons only for the layout lighting needed. When done, flip the wall switch and walk out. Cool, huh?

The room lighting will be conventionally controlled by wall switch #1. Train electronics will be powered by the wall outlet circuit which is totally independent of the lighting circuits. There, a single simple relay will be powered by wall switch #3.

Problem solved and it will all work as intended!

The sockets are on 24″ centers which fit nicely with my light panels which are also on 24″ centers. The sockets were attached with a pair of 1-5/8″ drywall screws through the molded-on mounting ears on each socket. A nylon cable clamp supports the cord between sockets. As best as I could manage the sockets are centered in each light panel along the valance. Every light panel has a lamp. In the areas over 2′ in depth (Lapeer, Kitzmiller, and Brittain roundhouse) the Party Lights also run along the backdrop. This should make the lighting more uniform in the deep bench work areas.

Next, I have to cut to size all of the light panels. The panels themselves are quite expensive – $8.97 ea. I need bunches of them. Even more vexing than the cost is figuring out a means of accurately determining the shape and dimensions of each panel based on the grid already installed. I haven’t quite figured out a solution to this problem but I am working on it. Fortunately time is on my side. I need to spread out the cost of the panels over a long period of time so I can ponder the solution for a while.

Between panel cutting I can also start the grid work for the ceiling over the aisles and the rest of the room. I have a sufficient quantity of wall angle on-hand to get a good start. Two years into train layout building and I still haven’t made it off the ceiling!

Now, stop laughing at the crudeness. This is just a quickly thrown together test. I don’t have my reflectors made yet for the CFLs so I used some tin foil. The acrylic sheet is .070″ cracked ice white and has not been cut to size. You can see where it is draped over the cross tees. The CFLs are 9W (40W equiv.) 5000K daylight lamps on 2′ centers 6″ above the light panel. The LED strip is a 6500K SMD5050 300/5M. The mock table top is at zero elevation of the upper deck – 53″.

CFLs and Reflectors

With Light Panels

Compare the table top, front of the power supply, and the backdrop in each of the following pictures.

CFLs Only – Too green, not evenly dispersed

LEDs Only – Too blue, not bright enough

CFLs and LEDs – Perfect!

Armed with a framing square, tape measure, mason’s string, and a pencil I measured and marked the locations on the wall brackets where the cross tees would be positioned.

Knowing that acrylic light panels are 23-3/4″ x 47-3/4″ designed to fit a grid 24″ x 48″ the measurements were made so the panel size was never exceeded. I wanted the panels to follow the layout in a flowing manner so as to compliment the flowing curves of the upper valance. A lot of trial and err was involved but eventually the positioning started to gel. The framing square was used to keep the tees at right angles to the backdrops. The resulting angle at the valance panel was cut on the end of the tees so they sat squarely and full depth in the wall track. This was especially important on the vinyl sections of wall track since the flexible vinyl part cannot support any weight. Mason’s string was stretched across at tee locations so I could visualize the arrangement before actually cutting any tees. The string made it very easy to reposition as many times as necessary to achieve the right spacing, look, etc.

Installing the cross tees was simple and straightforward. Measure, cut, debur, fit, drill, install with pop rivets. I did have to buy a new rivet tool. My old one hadn’t been used in a long time and somewhere must have gotten wet because the mechanism was rusted to the point where it would not work any longer. After messing with it for a half hour it finally hit the trash can. $9 later I was snapping rivets.

I especially like how the curved and corner areas came out. It really adds that flowing look I want. Lots of measuring to get them right but the time spent was worthwhile in the final results.

Next on the agenda – install the CFL lighting string in the valance.

The ceiling lighting has not yet been relocated. It will be moved once the aisle ceiling grid is in place so I know where to locate the boxes for connections to the lamps. With some of the bulbs right up next to the valance it tends to create shadows on any little defect in the plaster or hardboard work. That will all go away when the lamps are in the center of the aisles.

The valance looks much better in person than it does in the pictures. The camera lens does not have the same field of view as the eye so it is difficult to get a true sense of the flowing curves from the images. In person it looks pretty cool.

Installation of the lighting grid cross tees is next. In some of the pictures you can see pink mason’s string where I have begun to layout the positions. I’ll write a separate post once that step is nearer completion. For now there is a pile of cross tees awaiting cutting and riveting. More on that to come.

Placement of the wall angle was first order of business. The straight sections were easy enough. The mounting points on the backdrops were determined using a water level. Next, I cut a pair of wood blocks to 2″, the recessed amount above the bottom of the valance, and clamped them in place. This made it easy to properly position the wall angle.  The wall angle was cut to the same length as the respective straightening board above it. Once in position the wall angle was secured with drywall screws (if on a backdrop or wall) or #6-32 x 3/8 machine screws (if on valance panel).

Next came the curved sections after all of the straight sections were in place. My original idea was to notch wall angle so it could be bent. After a little experimentation I quickly abandoned that idea. The notched channel was unsightly and it would not form a smooth continuous bend. I went on the search for a better solution and found a company called Trim-Tex that makes flexible vinyl wall angle. Rob Spangler, one of the experienced guys on MRH, recommended it. Trim-Tex Pt.# 8159 seemed like the best choice and a building supply firm in Flint had it in stock. The Trim-Tex flexible wall angle is rigid PVC on one side bonded to flexible PVC on the other. Trim-Tex offers it in two different sizes and two colors – black and white. They even have a UV stabilized product for applications that will receive a lot of direct sunlight. I selected #8159 white since it has the smallest minimum radius. The white color is not an exact color match to the steel angle but certainly close enough.

A length of masking tape was placed on the curved panel between the steel wall angles and marked with the end points. The tape was then laid flat on the work bench and the distance between the marks measured. I found that if I cut the Trim-Tex material at 90 degrees the flexible part came up short of meeting the steel angles. Better results were obtained by cutting the flexible part at an angle on each end and then trimming to size with a razor blade after installation.

Trim-Tex is some pretty cool stuff. The flexible lip on inside curves gets all wavy when it is installed but a few passes with a heat gun magically straightens it out. The ends do need to be clamped else they will curl up from the heat. All and all pretty easy stuff to work with. I highly recommend the Trim-Tex wall angle for curved applications.

Below is a picture of the Trim-Tex wall angle bent around a 3-1/2″ post. They recommend a minimum diameter of 11″ but I figured what the heck I’ll see if I can convince it to form to a smaller radius since I had to do something to trim in the post. Its position forces me to work around it as it goes up through the lighting panels. I clamped a tin can of the same diameter to the workbench and grabbed the ends of the strip with vise grips. While my wife applied heat with the heat gun the strip was slowly pulled around the can. It took a lot of heat but eventually the molding conceded. Once in place on the valance more heat was used to stretch the flexible lip. As you can see there is a slight amount of deformation but considering it is bent to a fraction of its minimum recommended radius it isn’t too bad. It will look a lot better than if no trim at all were used.

With all of the lighting valance wall angle in place I was able to begin finishing work on the front side of the valance. It seems drywall joint compound will never leave my life! I sanded the entire face of the valance with 150g and began the taping and mud process. Wow, there were a lot of screws to fill. The second coat of mud dried for several days as a break in construction occurred over the Christmas holiday. Now it is time to get busy sanding. Oh, what fun!

As a design feature of the deck spacing, the backdrop panels are used at their full 48″ width which greatly reduced the amount of board ripping needed. The bottom edge of the backdrop is at the same height as the top of the lower deck bench work. 2″ foam for scenery will sit atop the bench work and in front of the bench work / backdrop seam. The top of the backdrop panel is 3″ above the bottom of the upper valance. The suspended ceiling grid will attach 1″ below the top of the backdrop panel which is 2″ above the bottom of the valance. Small scrap pieces of hardboard as spacers will be glued on the back of the lower deck bench work to get the spacing right so the upper and lower decks are flush at the front. Confused yet? Perhaps a picture is a better way of describing what is going on:

I found that drywall screws can’t reliably be used in hardboard as you would in sheet rock. Without a countersink either the screw won’t pull down into the hardboard without stripping or when the stud is tight wood the head of the screw often blows right off when the drill gets a good bite on the screw. I ended up countersinking all the screws. Word to anyone that uses their countersinking bit on hardboard – it wears out fast. The countersink actually worked best when it did get a little dull. With the hardboard only 1/8″ thick it was tedious at times to get sufficient sink without removing too much depth and having the screw pull right through. A dull countersink gave a little more control of the depth simply because it cut much slower. Anyway, another half bucket of drywall screws consumed.

Below is a little photo tour of where it stands at the moment. I am about halfway finished sanding the backdrops. The upper valance will also get sanded. Tape, mud, and paint are next on the backdrops. The upper valance can’t be finished out until the ceiling grid wall angles are in place so I can mud over the attaching screws. So the process going forward looks something like this:

1. Finish sanding backdrops and valance
2. Mud and tape backdrop screws and seams
3. Prime and paint backdrop blue
4. Prime and paint inside bottom 5″ of valance blue
5. Install wall rails of grid on backdrop and inner valance
6. Mud and tape valance screws and seams
7. Prime and paint valance blue

Once step 7 is complete I must make my final lighting method decision as lighting will have to be in place before I install the cross ties in the ceiling grid above the upper deck. I’ll cross that bridge when I come to it. For now, back to sanding.

Presently, I am gluing tabs across the end joints of each panel. Welding vise grips work perfect for clamping the tabs but unfortunately I own only a single welding vise grip. One tab a day it goes.

The next step in construction is to build the backdrop support wall for the south helix area. Essentially the same construction method as the north helix area except this will be a stand alone wall.

In the meantime I am testing various lighting methods. I wired the train room with a single 15A circuit for lighting. To my dismay I have discovered I need a higher capacity circuit if I am to use traditional florescent lamps to light the layout. There will be 133 feet of upper deck and 93 feet of lower deck that needs to be lit. Do the math… that’s a lot of florescent fixtures. Way too many for a single 15A circuit. Building code states that a circuit may be loaded only 80% for continuous operation. That means my 15A circuit is really a 12A circuit. Each twin tube florescent fixture draws 0.7A. 12 / 0.7 = 17.  17 x 4′ = 68′. My circuit can drive 68′ of twin tube florescent lighting or 136′ of single tube. My layout is 226′. See my problem?

Enter the LED strip. Low power consumption, low heat, uniform light, easy to mount and wire, sounds perfect, huh? I bought a 5 meter strip of SMD 5050 cool white LEDs to test. Temporarily wire tied the strip to a wood strip and clamped onto the valance. Love the color, love the uniformity, but just not bright enough to satisfy me. I installed a temporary tin foil reflector and angled the LEDs slightly which made it better. When I doubled up the strip it worked fine. Only problem with using two rows of LEDs is cost. Doubled up LED strip works out to be roughly $5 per ft for lighting. One could argue that I will recoup my money over time by using less electricity versus florescent but ouch. $1,100 is a big one time chunk of change just to light up the layout. The jury is still out on what lighting I will use. I don’t have to make a decision just yet anyway. There is much construction to be done before lights go in.

For now, it’s back to sawdust and nails as I build the south helix wall.