Lighting Overland Alco Century-series Number Boards


We need more heavy motive power for preliminary op sessions, so I’m back to finishing the Century 425. There is little space in the long hood because Overland soldered a cross support member that blocks much of the access. In the cab there seems nothing to offer support.

I’ve been experimenting with several solutions, none of which looked good. Most involved mounting 1206 surface-mount LEDs to the back of various stacks of white styrene. All produced horrible bright spots. Some previous locomotives received elaborate light boxes that spaced the LEDs away from the diffuser, but particularly in the rear of this locomotive I couldn’t fit anything comparable.

A few weeks ago it finally came to me to use a light pipe. A strip of 1/16" polycarbonate, ripped from an 8x10 sheet procured at a home store, was ACC’d to the back of a 0.015" thick white styrene diffuser, sized to fit the inside of the shell, and with enough overlap on the inside for glue.

Onto the light pipe two 1206 2700K warm white LEDs from Mouser were glued. The assembly, held down to the work table with tape, offered a perfect platform for attaching wires. These two LEDs, each of which drops about 3 Volts, are hooked in series. Then each end’s LEDs get wired in parallel, and fed through a single 1K Ohm resistor. There will be plenty of light, and because these LEDs came from the same reel (batch), and were made by Cree instead of a random Chinese vendor, they are very well matched to each other. Unlike siblings at the dinner table, they share current equally.

Once each was assembled and tested, I packed gray never-hardening modeling clay around the back to serve as a stray light dam. The clay also helped hold each fixture in place prior to adding a drop of ACC in each outside corner to permanently hold it in place.

Here’s an inside view of the rear light package. Each number board has 2 LEDs, one each for the two rear headlights, white and red 0402 class light LEDs on each side (white and black wires, respectively. Finally there is a single walkway light not visible near the bottom-center threaded mounting hole.

In the last photo we see the number boards from the outside. Prior to adding black background decals, the perimeter of the white area will receive black gloss paint to hide any gaps around the decals.

Yes, the upper headlight is loose and has slid outside of its brass investment casting. It will receive additional glue before the rear headlights are also packed in gray clay.

A Tang-Band 1925 speaker module will attach with double-sided tape, firing down, to the crossbar in the second photo, and another that is just the right distance inside the shell. Sound primarily exits open radiator intake air louvers on either side.

FYI the tiny 0402 LEDs were procured from German eBay seller LEDBaron. Each received a small blob of ACC to insulate the solder joints so that they would not short to the brass shell and cause a regrettable problem.


On the other hand, I have a couple C424s that will require considerable brass rework to install lights in the long hood. But for starters, I shot the cab so that one can appreciate the easy access to light the number boards, headlights, and class lights in the cab.

Inside the cab, the only difficulty is that there is are undersize holes on the inside for the headlights. That can be fixed using dental burrs and a die grinder, a/k/a “screaming banshee handmill”, a/k/a Dremel or Foredom shaft. I don’t advise attempting to drill them out. Don’t ask how I know, but something bad can happen.

When I first saw the inside of the long hood I had to say to myself “What was Overland thinking?” There’s a reason this auction site purchase came with MV lenses instead of lights!

Realistically, every O-scale locomotive I have encountered turned out to be a “Project” in some form or other. This one will be a doozy!

The first steps will be stripping a Reading paint job and popping out the MV lenses.


Sometimes I begin to wonder if I am smart enough for modern model railroading…



Jay, clearly you are smart enough for modern model railroading, you posted in an online forum didn’t you ?

Now… did you access the web via a “steam” powered DSL modem, or a “diesel” driven cable modem?
hum… he he he

…(yea I know what you mean these days though with DCC stuff)


I had the kids help with that. Hmm, maybe they could help with the DCC…

From things I read here and on he diesel list I really wonder sometimes.



Jay -

Don’t put yourself down, my friend! The number boards are just a result of failing dozens of times before arriving at something adequate.

You ran coal trains through Glenwood Canyon and are now a yardmaster. That says volumes. You know train handling, I know a little bit of geek. That’s all.

I remember the fabulous D&RGW diesels you rebuilt and detailed, brought to club meetings, and ran on the DG&T. That was precision work I could never replicate, even in O-scale. The larger scale just makes it easier to see my mistakes, such as two gaps I forgot to putty on the ends of the radiator bump-outs!


It’s stunning Bob, the parabolic reflectors are out of this world. Are you going to weather it pretty heavy or light? What a beauty.


The A&O is set in 1968. C425s were built from 1964-1966, so this unit is just a few years old. It is dirty but not derelict.


What is your latest choice for the grey and red?


Jay -

I wish I had a good answer for you. This one was airbrushed with “unobtanium” paint, a/k/a PollyScale. The red is straight Pacemaker red, but oil paint weathering washes made it look a lot darker. The gray should be warm. I used a mix of Milwaukee Road gray and concrete. David’s reference color is Floquil concrete. Frankly I’ve never mixed a gray that brown. Maybe I’m a rebel (that’s what my uncle Ben called me.)

I ordered some bottles of TrueColor paints but haven’t yet shot color chips. I wonder if their D&H gray would be warm enough, or perhaps a mix with TC concrete.

I used a new gray primer, Badger’s unpronounceable polyurethane Stynylrez after watching glowing testimonies from aircraft modelers on Youtube. I’m sold, but must confess I bought a Paache single-action airbrush with a big diameter needle just for the primer. Badger says don’t thin it, and it worked just fine straight from the bottle even though it was thick. Next time I’ll try their black primer on locomotive truck side frames.


Just discovered that TruColor has Pacemaker Red…


Yes they do! I have a bottle of their PM Red and hope to make a paint swatch pretty soon. The new Caboose in Denver appears to carry the entire line. I may need to make a trip in the near future to pick up all the warm grays I can find, including concrete.

For me a downside of TruColor is that it has a highly-volatile solvent base, even though it is an acrylic. Acetone can be used to cut it, though the TC thinner has other stuff in it and I can’t find an MSDS for it. I care because, although I have a two-fan spray booth with outside exhaust, it fits in a basement window. Across the basement I have gas pilot lights in a furnace and hot water heater. And I like having a house above my basement!

If I recall David used Floquil PM red on his C430 but it was a somewhat different shade than the PollyScale. Anyway after weathering there are no two locomotives that look exactly color matched. And I can’t seem to find the color mixture I used for the gray on my C425. I have found that Golden high-flow acrylics for airbrush do mix nicely with the old PollyScale. But those are water-based not solvent-based.


Yeah, that’s why I haven’t tried TC yet. Not water based.My spray booth is a “box” made out of furnace filters taped into a box with a box fan on one end. Really can’t use volitile paint with that setup. My basement doesn’t even have a window to vent out of…


I hear you, Jay.

My spray booth is made from foamcore board, a furnace filter, and couple of 110V computer box fans to pull air through the filter and into an external plenum. The width matches my basement window well. Another sheet of foamcore blocks the rest of the window opening. If the wind isn’t blowing in, it works pretty well. And as long as a bird hasn’t dropped dead in the window well and stinks to… ahem. Been there.

Have you considered trying your booth outside on a warm but bug-free day? Or maybe in the garage with the cars parked outside and the door wide open?

If I recall I heard second-hand of an RPM modeler who airbrushed his diesel with TC on the deck of a hotel room the day before and managed to get all the decals finished just in time. TC is reported to dry very quickly. Did I hear that one from you or Rick?


I use the TC for some projects, hit it with a hair dryer and it’s like Badgers Modelflex, it’s ready for decals or tape off another color right away.


Nice to hear that they dry quickly with a hair dryer.

A few days ago I shot a bunch of TC paint chips. Some I’ve had on the shelf for about 6 months, others were newly-purchased from Caboose in Denver. When I approached the rack of TC paints, I detected a strong aroma of volatile organic compounds. The bottles were outgassing.

Opening my collection of samples here, some were already noticeably low, about 1/3" down. Prior to opening any there was a faint aroma of the solvents. I went through a full bottle of their thinner just refilling the low ones.

One color, D&H gray, was a warm value 5 (about 18% reflectance.) That’s way too dark! It was just as dark as the gray Stynylrez primer I shot as a base coat, but it was a bit warmer. Concrete and aged concrete look identical, at least from the two bottles I sampled. Not good… Out of curiosity I may measure these three, and the primer, with a spectrophotometer I bought years ago for digital camera and scanner color science work.

I do wish TC provided dealers with actual paint color samples for customers to examine. Golden high-flow artist’s acrylic paint bottles each have a swatch of real paint brushed over a white/black zebra stripe on the label. The TC digital online samples are useless.

I solved the problem of spraying acetone for clean-up with an Iwata spray-out pot. It worked wonderfully when placed in the spray booth and up against the filter.

Has anyone found an MSDS for TC paints? There must be one somewhere!


I understand the off gas is a byproduct of the plastic bottles. Acetone will replenish the loss of solvent. Besides the obvious health issues of spraying acetone I found out the hard way to make sure you spray the correct series for an airbrush and not the flat brushable series. I have sprayed TC with success but concerned about the acetone. I made a spray booth out of an old rear projection TV that I vent to a window in the basement and spray with an organic cartridge mask. Maybe it’s no worse than Scalecoat which is my go to paint. Speaking of which, through email I have spoken to the owner and if provided a paint sample he’s willing to look at colors not currently in the line.


Hmmmm. Guess it’s time for me to get a paint booth setup. I like all of the ideas on construction.

Bob - can you help me with a few questions.
1). You mentioned some LEDs from CREE as your number boards. Do you have a PN for those by chance? At Mouser?
2). In your number board shots you have the styrene backer going on the inside of the shell. What are you doing for the “glass” in front of the styrene? Or did engines not typically have a glass front or cover on the number boards?

Bob knows this, but I’ve bought another O scale engine to help out the A&O fleet. It is an Overland RDG GP35. It needs a little work but all in all it’s not bad. I have the trucks repaired and the pickups rebuilt and the pickup board created ( with TVS I might add -thanks Bob). I’m envisioning this being a patch job for the A&O, covering any Reading markings and being replaced with A&O ones.

So far it’s been a fun project.


Craig -

I’m using Cree 1.6mm LEDs for headlights, mounted in lathe-turned reflectors. The Mouser part number is:
941-XQBAWT020000HXE7, 3000K.


It is about to be obsoleted so I’d better order a bunch more! These parts are insanely bright at 10 mA but mechanically they are very delicate. The tinted lens loves to separate from the silicon carbide base.

Each headlight pair is wired in series and uses a single 680 ohm dropping resistor. The Loksound decoder has a light dimmer for each function output so they can be dimmed if too bright. Here’s a link to the headlight design:

Alternatively NCE’s warm white 3mm LEDs work well. These are available from a number of vendors and come in inexpensive 10-packs. These can be inserted directly into the headlight castings with the LED lens just proud of the outside mounting ring.

As for the number boards, I use my standard “go to” 2700K surface mount LED. The Mouser part number is:


These too are scheduled to be discontinued! Some time ago I bought a reel so I’m well stocked.

Prototype number boards were generally translucent white plastic with black paint on the outer surface. For the C425 I will print ALPS decals, clear numbers with a black background. Once I establish where light needs to shine through, I will paint the perimeter of the white styrene gloss black. That way the decal will not need to precisely fill the opening. If the gloss seems non-uniform then a quick bit of brushed-on Future will make things right.


Just got my LEDs ordered a few days ago. Ordered up 500 so that should put my stock at around 750-800.

I’m going to start working on the number boards today with it being so wet outside. No work in the garden today.