Our Halloween Ghost Town

 

The Idea…

We transformed our downtown marketplace into a ghost town for Halloween. The idea that the empty building faces already made it look like a ghost town played right into it…

But we needed more than those same tired buildings I cast so many years ago. Something more than three storefront apartment buildings. Something big. Something Grand. Hello Grand Hotel!

But that still wasn’t enough. Those foundation blocks with their corner cutouts have been patiently waiting for some attention too. Hello Corner Drugstore!

All of these additions came together in the few weeks before Halloween. Most of the groundwork began in September, but filing our taxes stole time away from our goals. And we had many goals.

Glow in the dark ghosts. Lightning bolts striking the Grand Hotel sign which would then remain eerily lit. “Uncanny eyes” gazing about in the hotel’s elevator houses atop the towers on either end. Even a drive in theater playing horror movies!

The Result…

Alas, those were not to be, but there’s always next year. We are more than pleased with what we accomplished though! The customized lighting effects stole the show. They were the show!

Eerie “ectoplasmic” colors fading in and out. Bright blues coupled with flashes of lightning give the impression of dramatic and destructive electrical explosions. Surging waves of blood red, as if the building is breathing.

Here’s a look before we even had the Corner Drugstore finished!

The History…

It all started with the desire for better lighting inside our passenger car “fleet”.

All but a handful of these passenger cars are Bachmann, the style with two light bulbs inside and a 9V battery box beneath to power them. They really couldn’t be seen until dark and the battery usually only lasts a few hours until it’s dead anyway. Not real impressive…

I used 5050 LED strips for everything, starting with lighting under our patio train station platform… All 16 feet of it! These were pre canned light strips, complete with remote control and power supply. I even dug in an underground feed right to the corner of the platform dedicated to powering it.

The next step was to fit shorter segments of those strips inside a passenger car. This had a number of drawbacks. First, while small, the Arduino controller still didn’t fit inside the existing battery box. The Lithium battery is slightly larger than that. I designed and 3D printed one large enough to replace the existing battery box.

Fast forward to now. Many iterations of the design later, I switched to using 2812 individually addressable LED strips, for a number of reasons. What’s the difference? The power supply for one. The 2812 strips run on 5V, the 5050 strips require 12V. Not a showstopper, but it does require extra parts to boost the 5V supply I already have to 12V.

The biggest difference between the two types is the ability to address each LED on the strip individually with the 2812 style. While the 5050 version allowed me to mimic the effects of the pre canned units, I wanted to be able to have them individually flicker, even scroll in marquee fashion!

The Effects…

I started with the easy effects, jump, fade, flash, blink. I added the ability to individually address each “pixel”. Then I added the flicker. It can be adjusted to be as slow and subtle as a kerosene lamp to as fast as an arc welder, with a flickering candle flame somewhere in between.

The problem is all the effects are global in nature. That is to say, they affect ALL the LEDs at once. Only the “per pixel” selection allows for changing each pixel’s color independently from one another and the ability to scroll them (marquee).

I spent a good bit of time to marry the two versions together… The issue I have to solve is the all or one addressing, or rather, pixel addressing and grouping. In a nutshell, we have baggage cars (no lighting whatsoever), combination cars (baggage and passenger sections), full passenger cars, and what I’ll call a parlor car (with an additional lit herald on the back railing).

How to handle all these different situations in ONE implementation? The hardware was identical, with 24 LEDs for each. The only exception is an extra 3 LEDs for the herald. The software is as generic as well. Each car has its own configuration that describes its unique situation.

If I haven’t mentioned it before, all these “gadgets” use a web browser interface for control. The embedded Arduino controller has built in WiFi. It operates as an access point that will allow other devices to connect to it as well as connecting to an existing WiFi access point as a client.

All of this allows the Arduino to act as a web server, serving up the control interface web page, available to any device on the network! Smart phone, tablet, laptop, you name it. If it has a web browser, you can control it!

I’ll add a video capture of the interface in action soon…

The old version only accounted for baggage and passenger sections of the combination car. The herald lighting wasn’t even addressed. It’s a step by step approach. First the LED and group addressing. The next is modifying the effects selection for each group and pixel.

In the process, I had to “wedge” the new additions into the existing status reporting mechanism. I pretty much gutted the entire per pixel reporting mechanism and refactored it to better fit into the group addressing scheme. Needless to say, the per pixel addressing functionality was the last to come back online.

Without getting into too much detail, there are two sides of the coin we’re talking about here. The client side and the server side. The client side is the browser client, consisting of HTML web pages, CSS for styling, and javascript for the nuts and bolts programming “smarts” behind the button pushes and handling the web socket interface to the web server.

The web server is the Arduino side, serving up the control interface pages and taking the appropriate actions when commanded. If this is all Greek to you, that’s alright. It’s a lot of programming jargon if you’re not interested.

If you are interested and would like to know more, leave a comment and I’ll be happy to answer any questions you may have. If there’s enough interest, I can add more detailed posts that describe how this all works.

The Ghost Town…

I had to further adapt the passenger lighting controller to become the ghost town controllers, starting with the Grand Hotel. But that’s not the only thing we needed. It would help if we actually had a Grand Hotel! For that, I cobbled together a number of 3D print designs I’d been working on to improve the casting process in the form of custom molds.

After many iterations, I finally managed to match the brick pattern sheets I used to cast the original storefront apartment buildings. In fact, I came up the the positive version before converting it to the negative impression suitable for use as a casting mold.

With a few changes here and there, I can print the various pieces of a building, one floor at a time. In essence, I’m converting a concrete block into a building using a 3D printed skin, one 5″ x 8″ section at a time. The sections are then joined together similar to styrene models, using a different liquid cement (chloroform), together with brick strips that mimic columns and headers.

If you’re a model railroader in smaller scales, you’ll recognize the approach is similar to Design Preservation Models modular kits. They supply a set of walls, window, door, and other detail castings, and the assembly instructions. All you need is glue and paint.

The resulting “skin” then slides over the block, after painting of course! It’s obvious the window frames and glazing are missing, but that’s what prompted us to make it a ghost town in the first place! The original buildings had both window frames and glazing in addition to a ground floor store front at first, slowly demolished by continued collisions with the pups.

I start by assembling floor sections together into a single three story wall then comparing it to the block. My first attempt fell short… Literally. Had I butted the brick header strips together with the sections to be joined instead of overlapped on top of them, it would have been just about the correct height.

The Grand Hotel…

Armed with this information, I began to madly 3D print wall after wall. I already had a few walls that I had previously printed, attempting to recreate the existing storefront apartments. My first attempt left too large an opening for the windows. The next attempt matched the window openings very closely, but added an extra brick to the width.

Great for ¼” thick castings… For a 0.072″ plastic brick sheet, not so much. The great thing about thin plastic sheet is how easy it is to cut with a good pair of scissors! Not Kindergarten scissors and construction paper easy, but easy enough to trim half a brick off either end without much bruising…

This is a seat of the pants operation here. It doesn’t need to look perfect and it doesn’t need to last, it only has to resemble a big hotel from a distance at dusk. If you look closely, you’ll see there are no doors anywhere on the ground floor. Kind of like Hotel California, “You can check out any time you want, but you can never leave”, assuming you could get inside in the first place!

In any case, I soon exhaust the entire replacement spool of yellow filament. I screwed up getting the hub to fit inside when I first got it and it’s been hanging there ever since. The fear was a tangle in the line will cause a knot and jam the printer extruder. The result? A failed print at the very least. A flying spaghetti monster if not caught in time.

I was lucky this time though. I was present for most if not all the printing. Each section takes about three to four hours to print, so I continue to update my Arduino code while printing continues in the background behind me. Not only did I exhaust that entire replacement spool, I went through another regular spool as well, plus part of a second!

I had to wait on the second regular spool to get here too! The hotel is complete except for a few sections, so at least the side that shows looks like the Grand Hotel.

The Corner Drugstore…

The Corner Drugstore was meant to be printed from a spool of brick red colored filament I ordered especially for it. There’s something to be said for sticking with the known quality of a brand of filament. Apparently, I chose poorly… I tried three times to get a print just to stick to the bed before I finally gave up and threw it off to the side.

I loaded up my usual brand of filament in the bright red variety and had nothing but perfect prints one after another. This building is different than the others in that the corner entrance wall and doors will be at a 45° angle to the side walls. With barely enough time left to print the side walls themselves, I didn’t take the time to design the entrance and the 45° column pieces.

I did design a different set of window walls though. Two large windows per section for the bottom floor, as if there is restaurant seating, and four small windows for the middle floor sections suggesting a mezzanine. The upper floor sections are the standard three window apartment style windows.

I even added a set of alley side carriage doors with a small office door beside them. It went together quickly, but not quickly enough. I was still adding those finishing touches Halloween night! I ran out of time to cut the aluminum extrusions to size for the LED strip to fit inside.

Not even the original storefront apartment buildings had them, just the Grand Hotel, and even then those were cobbled together and barely fit inside the blocks. I needed something to diffuse the bright spot source of the LEDs. Even with the diffuser covers snapped in the extrusions over the LED strips, they can still be seen and it’s obvious they’re LEDs.

The only “pictures” I have are actual video recordings of it, and even then it’s just the incomplete skin. At least it’s painted brick red and has the lighting effects installed! It was a rush job to say the least. I was lucky to get as much done as I did. Here’s what the end product looked like. Hope you enjoy it as much as we did!

Most of the work remaining on it and the rest of downtown will wait until the new Main Street design is finished. The idea is to pour a thin concrete “sidewalk” that will serve as Main Street and the side streets, including curbs, sidewalks, and a firm, level foundation for all the buildings. But that’s another project for another time…

The Code…

The code has evolved over time, based on the success of previous additions from various projects. It all started with the WiFiTrainController Arduino sketch Nick put together a few years back to control his Lionel trains. Between his inspiration and my renewed immersion into embedded systems control at work, there’s a strong motivation to return to my “gadgetronics” days of the past.

After a number of iterations of modifications, and many failed attempts at getting reliable readings from Hall effect current sensors, I finally stumbled across the resolution to the problem. Unfortunately it meant going in an entirely different direction. That resulted in more iterations and improvements, and some refactoring along the way.

All that work on the block and motor controllers paid solid dividends going forward. The expanded web socket interface was far beyond the original single character command approach. Adding new commands is as easy as adding the command keyword to a map of handlers and pairing it with a new command handler to take the appropriate action on the server side.

This scaled nicely when I began working on the passenger car lighting projects, the direct ancestors of these building lighting effects projects for Halloween. First it was my “Glow In The Day” clocks, 3D printed in glow in the dark filament, then illuminated with UV LEDs to glow in the daytime. Now it’s the downtown ghost town.

Actually, it’s three separate projects, one for the Grand Hotel, one for the original Storefront Apartments, and one for the Corner Drugstore. The code for all three is basically the same except for the number of LEDs controlled and the user interface pages themselves.

In more detail, the projects consist of an Arduino sketch (written in C) and the data files. The NodeMCU 12E controllers are ESP8266 based and contain 4MBytes of flash memory. This can be divided between the two parts, in 1MByte increments.

The program sketch is compiled into an executable binary that is uploaded to the first part of flash memory. The data files are stored using the SPI Flash File System (SPIFFS). It’s a flat file system, but provides hierarchical storage via the file name itself. This is where the web pages, CSS, and javascript files are stored that are served to the web browser.

Here’s a video example of how we select and control the lighting effects we used for the ghost town. As you can see, there’s even enough room in the flash memory for a couple of smaller image files.

The Finish…

I used a dedicated power bank (20,000mAh) each for the Grand Hotel, Storefront Apartments, and Corner Drugstore. Each had its own dedicated Arduino controller as well. I was able to connect to each controller with my phone and the office PC to control them! The only thing I wasn’t able to pull off was the passenger car effects.

I thought I could spend a couple hours and get something whipped in to shape and working, but it was not to be. In fact, it took more than another week to get things the way I wanted them to work. But that’s software. If you wait until it’s perfect you’ll never have anything to ship!

As an experiment, I left the effects running all night long. They were still going in the morning! The power banks were fully charged Halloween night, with somewhere between 25% and 50% of the 20,00omAh charge remaining. I was also quite aggressive with the LED levels for a more dramatic effect. More conservative selections would last even longer.

By comparison, the passenger cars have only a tenth of that power (2,000mAh), and with more subdued lighting levels they are still running in the morning as well. I can get anywhere from 8 to 12 hours from them on a single four hour charge.

Stayed tuned for more updates on the passenger cars and the Barkyard too!

 

 

 

 

 

Happy Anniversary!

It’s Our 38th Wedding Anniversary!

Getting Ready For Fall

Ann and I were chatting about the Barkyard this morning and all the things we want to do. All the things we still have left to do. Things like launching the website so that it’s more than just a landing page. Things like producing videos with trains, not just the pups. After all, it is the Barkyard Railroad!

Our “online presence” is still under construction, to borrow a now antiquated description from the web design museum vault. These blog posts should help fill out content, but the idea is to welcome folks to our Barkyard and to share our enjoyment. Share our experiences. Share the latest developments.

It’s almost September already, what most folks would consider the beginning of Fall. Ann is ready to start the transformation from Summer to Fall. Fall colors. Fall flowers. Fall decorations. You know, bales of hay, scarecrows, pumpkins. Those sorts of things.

Ann mentioned how the “Downtown Marketplace” is looking more like a ghost town these days, and she’s right. We had storefronts and windows and streets, but the constant pounding from the pups have reduced our buildings to empty shells. The streets trampled to rubble.

While it’s a bit disappointing, it just another “puppy proofing” opportunity. We hope to have the time to transform downtown into a true “ghost” town for Halloween, with more castings, lights, perhaps even sound. It’s an aggressive schedule and will take time to accomplish to be sure.

Our Plans

Here’s of photo of what we have to start with for the ghost town. Those three buildings on the left used to reside in the gap to the right. Ann moved them out by the switches to act as a block to keep the dogs from destroying the now unobtanium turnouts.

Ghost Town
Ghost Town

Where they stand now was supposed to be the site of the Grand Hotel, but we never really figured out how to make the castings work for anything more than a single concrete block. Well, not so much figuring it out as much as moving beyond the limitation of a single casting no larger than a concrete block, constrained by the size of the largest pattern sheets.

I’ve been designing some new 3D printed molds that can be joined together into a single, larger “all in one” mold. Our largest pattern sheets (15″ x 15″) are more than four times the size of the available print area (8.5″ x 8.5″). That work is on hold at the moment while we continue on the website. It won’t be long now though. To give an idea of how long it’s going to be, the photo is already more than a month old.

Maintenance is another big ticket item. We had just finished replacing more rotted wooden stringers. You can see a couple of new slats sitting on the sawhorses in the background. We found out the hard way that even though those stringers are not sitting in direct contact with the ground, the dirt splashed up by raindrops is just as hard on them. But we’ll cover that in another post.

Once we get past Halloween, we plan to “refurbish” Main Street. We used “Hardi-Backer” board as the “pavement”, cut to size, and surrounded by concrete block “caps” to simulate a raised curb and sidewalk. While the “Hardi-Backer” holds up to the elements and resists rot extremely well, it’s no match for the constant pounding.

The plan is to cast the streets in concrete, and the sidewalks and building pads for that matter. Perhaps even casting a brick veneer to simulate old time pavers. Brick streets were far more common than concrete roads a century ago. Some brick roads remain in the NE Ohio town where we grew up. Even here in Apopka FL!

What’s Next?

Our intent is to increase the amount of video footage we share. At this point, anything would be an improvement to the handful of short clips of the pups on Facebook. We don’t even have a trailer for our YouTube channel yet!

Feel free to leave us a comment.

Adding Details To Downtown Building Castings

 

The Featured Image above shows the results of our efforts so far. Below is what we started with… Three very rough castings obviously covering concrete blocks.

Rough Castings
Rough Castings

I’m designing the downtown market display case view blocks to conceal the edges of the concrete block on the first floor. I don’t really have a specific example of a building to model in mind, just a vague recollection from my childhood of what buildings looked like.

The building itself is based on some of the HO kits I assembled ages ago. These kits all start with the same narrow faced three story building, but add different details, like a funeral parlor or a five and dime. The bottom floor is always different, but the upper floors have similar window frames and clear glazing. Even brick patterned blanks are supplied to close off openings if desired.

I’ve already designed the window frames, experimenting with different glazing. With nothing to conceal the concrete block behind, it was obvious something was needed. First I cut some opaque black ABS to fit behind the frames. It definitely blocks the view! But unfortunately, it also means lighting is out of the question!

Downtown Marketplace Windows
Downtown Marketplace Windows

In the Featured Image, the building on the right shows the different between nothing behind and black ABS. The building in the middle show what the translucent green looks like compared to the ABS. None of the building have the display case view block installed yet. See the end of the post for a view of all everything populated.

I’m also trying out the “see through” dark green filament I bought, as a stand in for the soda glass of the day, or perhaps tinted glass on automobiles. Hopefully. It’s a little dark for the window glazing, but looks better than the clear filament, which is anything but clear. Translucent perhaps, but it just looks too white and opaque.

When I had just the black ABS cutouts behind the frames with no glazing it looked better than the translucent “clear”. And now the new translucent green looks better than the ABS view block. I need to experiment with back lighting and see if it still looks as good.

Even my “venetian blind” modification doesn’t look like anything but opaque white! It works only slightly better with the translucent green. Perhaps once it’s backlit it will look like blinds covering the inside of the windows. We shall see…

Downtown Marketplace Window Glazing
Downtown Marketplace Window Glazing

Iterations and Alterations

Just as the window frames underwent a number of modifications, so did the design, fitment, and assembly of the display cases. The original casting is meant to have two display cases behind large, transparent windows, one on either side of the entrance which is placed in the middle between the two.

The entrance represents a metal framed door with a transom above, typical of the era. For variety, the transom can be fitted with a more modern air conditioner. For now, I’ll concentrate on getting something there first. Details can be added later.

The entrance will be assembled from the three pieces previously described, due to limitations of 3D printing. Overhangs are a no-no. They can be overcome using supports, but it’s more work to clean up the traces left behind by them. The tradeoff is gluing the pieces together, but how to glue them together? We need something to glue together first…

Printing Storefronts

The beauty of the design’s symmetry is both display windows are identical, allowing both sides to remain a single, interchangeable assembly. Together with the door assembly, they can fill the void of the street level opening meant for them.

I recently purchased an assortment of “metal” filaments for the 3D printer. I’m hoping the silver looks enough like an aluminum frame to pass as metal. Even just the standard silver (gray) filament will look enough like an oxidized galvanized finish, so it’s not really a problem if it doesn’t. It still looks better than nothing!

I already printed window frames using the plain silver gray filament, so I print a set using the silver metal filament first. The showcase frames have a place for colored insets above both the door and windows, as well as the bottom kick panel of the door.

Rather than print the insets in the gray color, I decide to use red to make it “pop”. I refrained from printing more window frames in red for fear it would be overpowering against the brick red of the casting. The gray will work well enough for now.

But the real test will be the copper color! I’m thinking about using it for the cream colored brick building, together with brown inset panels, to really make it “pop”! I can’t wait to try it, but wait I’ll have to.

Assembling The Storefronts

My first prints of everything need revision! The frames don’t fit together the way I want them to without a redesign. Even then, the next version still needed some judicious filing, but that left the fit too loose. Even the insets don’t fit!

I quickly learned I need to leave about 0.010″ clearance between pieces if I want an exact fit, and by exact I mean almost an interference fit. I reprinted the insets and this time they almost “snapped” in place. I say almost because they are just loose enough to find their way back out on their own.

So not only do the frame pieces need to be joined together, the insets will need something to retain them in place as well.

Plastic Welding or Plastic Cement?

Even though we’re talking about adding details to cement blocks, the plastic cement we’re talking about is like styrene model cement, the kind that chemically dissolves the plastic together to create one solid piece once it flashes off.

I’m not sure what glue works on PLA. Acetone works for ABS, and supposedly for PLA too. A quick test says I don’t know what they’re smoking, but it has no effect. Model glue does a little better, but still leaves a lot to be desired. That’s not working. Next. I read good reviews about using a plastic welder, so I decided to buy one and try it.

The ones most recommended double as a child’s “toy”, but I’m not sure what parents would hand their grade schooler a hot melt glue gun these days. That’s basically what it is, except it uses plastic filament for 3D printing instead of glue sticks. And at 210°C (410°F) for PLA, it’s about twice as hot. May as well hand your kid a soldering iron at that point!

When it arrived, my first attempt at plastic welding two parts together worked, but with mixed results. It effectively joins the parts together, but the joint isn’t very strong. And like welding metal, it leaves a visible bead of material at the joint. Let’s just say it doesn’t look like a stack of dimes…

After assembling the first storefront, I am thoroughly discouraged by the results. Even though I was able to keep the ugly weld bead hidden from sight, it doesn’t hold the assembly together long enough to press it into the opening in the casting, quickly snapping apart!

My assumption that it physically heated both parts to welding temperature while adding filler material was not a good one. It basically melts only the filler material. There is no molten “puddle” of material like metal welding.

PLA Cement a.k.a. Dichloromethane

A bit more research finds that dichloromethane is the solvent I’m looking for… a.k.a. chloroform. Great. Now where do I get that? Even after all the “Does this rag smell like chloroform?” jokes, it’s surprising how many products use it as the main ingredient! Methylene chloride was widely used as a paint stripper, now both are banned banned, replaced by a far less effective ingredients.

Just be bopping down to the paint department at the local big box store sounded like a good idea at the time, but they no longer carry methylene chloride, let alone in those gallon tins. Guess I should call myself lucky to still be able to buy acetone by the gallon.

What’s amazing to me is there are still many suppliers online. I went with “WeldOn” products, no affiliation. It’s expensive for just a pint can, but they deliver to my door! There are a number of different “acrylic adhesives” in their lineup.

I tried their #16 first, which worked incredibly well on plexiglass, but is really thick. Too thick to seep into the crevices between the parts via capillary action. It works, but has to be brushed on, wasting a lot of it in the process, kind of like using a firehose to water the flowers.

I ordered their #3 and #4 variations next. They are definitely liquid, thin enough to flow into the tiniest of crevices. The #3 is quick acting and the #4 has a longer working time. Both flow easily into the joints. All three should be used only in a well ventilated area or asphyxiation could result.

Along those lines, this stuff needs to be tightly sealed so it won’t totally evaporate away. Both the #3 and #4 came sealed in heavy duty ziploc bags over the sealed metal lid of the metal can! The first time I used it, I found out the hard way how quickly this stuff evaporates!

Learning the Ropes

The small squeeze bottles with attached hypodermic needle that came with them have a twist-lock “cap” of sorts to protect the tip. More like to protect you from stabbing yourself with it, but even that wasn’t enough to seal it. I had a third of the squeeze bottle worth of #3 left in the bottom when I went to bed. It was all but gone by morning!

From now on, any leftover gets immediate placed back in the can and then sealed in the ziploc. I also found the needle to be prone to clogging with the dissolved plastic after a short amount of use. Squeezing it to blow out the clog either doesn’t work, or if it does, floods the work pieces with solvent.

I found a better way to dissolve the clog was just to hold the squeeze bottle upside down until the solvent itself dissolves the clog. It doesn’t take long and it’s fairly obvious when the clog is gone. Hard to ignore the solvent that starts streaming out again. After the first few uses and it taking forever just to get enough sucked up into the squeeze bottle through that small needle, I decided to find some larger versions.

I now have so many of them, I can’t give them away, but the thought was they would fill quickly and I could use them to quickly transfer the contents into the hypo bottle. They came with an attached silicon cap to cover the larger, blunt tip, but even they don’t seal well enough to leave any leftovers inside for more than a day or so. I’ve gotten in the habit of pulling out a little solvent at a time, using what I need, then returning what’s left to the can when finished.

The Test of Time

So long story short, after a few false starts, we finally managed to get those three buildings looking more like a downtown business than a concrete block. They still need modifications to continue to serve us as downtown marketplace buildings though. The elements were not kind to the PLA plastic, as seen in the picture below.

Faded Glory
Time takes its toll on the PLA plastic exposed to the elements

I should have used some adhesive caulk to hold the windows in place too. Slowly but surely the dogs managed to knock out every single window. It got to the point that every time I went out to work on the Barkyard, I had to pick up a couple more windows, just laying in the street or on the ground. I started a collection of them in the garage so as not to lose them.

Next go round I’ll need to paint the plastic with UV resistant paint, maybe even just a clear top coat, but an opaque color will provide far more protection from the sun than clear coat ever could. At some point I really need to get some display cases put behind there though.

I finally removed the ground floor display cases and stashed them away too. Ann says it looks like a ghost town. So we’re thinking of making more castings, enough to build an entire ghost town downtown for Halloween! I’ll need to accelerate my efforts to add lighting and other “spooky” effects, but it should prove entertaining regardless.

Our First Casting

Why Casting?

The title should really be “Puppy Proofing”. They can certainly inflict some serious damage! One of the main themes of the Barkyard Railroad is sharing the space with the “pups”, so everything must be built much stronger than normal in order to withstand a direct impact from a hundred pound German Shepherd at full gait.

Another consideration is the longevity of any structure outdoors, under constant bombardment from the elements. Most plastics quickly becomes brittle after baking in the sun. Even treated lumber quickly rots in this environment.

Along those lines, I found an interesting approach to outdoor structures online, in the form of cast concrete. More accurately, cast concrete patch. I will include some links to this inspiration, as well as my source of pattern sheets for casting.

Lay out
Test fitting

A brief introduction to the technique is warranted. Using extruded foam insulation as a sort of “backer board” for the pattern sheet(s), inserts for openings like doors and windows are also fashioned from the rigid foam, then “T” pinned in position over the pattern.

Pinning Together
Pinning it all together

There are many different types of pattern sheets available. Brick, concrete block, lap siding, and corrugated roofing are but a few examples of the many types of pattern sheets available. I started by acquiring an assortment of different pattern sheets from various sources.

Although a specific pattern sheet may be found online, its availability is certainly hit or miss, especially when searching for G scale items. But that seems to be a common theme for anything G scale. The next obstacle is finding suitably sized pattern sheets.

Patching a mold together across multiple pattern sheets is problematic at best, creating a “parting line” effect in the casting. To avoid this, I chose to start with a 15″ x 15″ square brick pattern sheet. The resulting casting will cover one side of a concrete block, roughly 8″ x 8″ x 16″ in size.

Why a concrete block? Because it is immediately more puppy proof than just a thin casting. This technique also calls for an embedded wire mesh frame to provide strength for the brittle casting. The issue becomes how to manage parts that require multiple castings to complete due to their shape or size, a pitched roof casting for example.

For a pitched roof, only one face or the other can be cast at once since the mold must be level. But the mesh must be formed at an angle across the roof peak, with the other half protruding from one side’s casting until it cures. The other side can then be cast, but this presents the unique challenge of fixturing, somehow propping the previous casting in place while the new one hardens.

There is no easy way to cast a four sided building using a single piece of wire mesh. The challenge of keeping the first wall standing and squarely aligned while casting the second wall is difficult enough, but consider trying to hold three walls in place as the fourth is cast.

That last wall would also require somehow connecting the ends of the mesh together, either from the start, or allowing enough to extend from the first wall to fasten to the other end of that last wall. Extending the thought of somehow connecting the ends of the mesh together, just folding up the edges to leave about half an inch of the mesh exposed should do the trick.

Mesh Insert
Wire Mesh Insert

The Pour

With everything pinned together and the mesh cut to size and in place, it’s time to mix up the concrete patch and pour. Having never done this before, the consistency of the mix is in question. “Pancake batter” can range from runny to thick enough to require a ladle, so opting for somewhere in between seems the best bet. A dedicated mixer is recommended, so opting to hand mix presents its own challenges.

While the mix slacks, everything is sprayed with the mold release agent, WD40 in this case. Although the “batter” seems to be thoroughly mixed, the patch wants to settle out to the bottom of the mixing bucket. The closer to the bottom of the mixing bucket, the thicker the consistency becomes. Working around the inserts is difficult with the thicker mixture and even a small trowel isn’t helping much.

The Pour
The Pour

Once poured, the mix needs to be vibrated into place to remove any trapped air bubbles, like real concrete. A handheld jigsaw was recommended, minus the blade of course, but a palm sander will do in a pinch. The idea is to vibrate all around the mold, and for long enough to allow the bubbles to float to the surface and burst. Now all that remains it to let it set up for 24 hours then remove it from the mold.

The first attempt at removing the bubbles proved to be an exercise in futility. While the plywood bench all around the insulation base was vibrated, many bubbles remained trapped. And while all those minute voids in the casting can be filled, it’s more trouble than it’s worth. The take away is next time, the mix must be thinner, and the mold itself will be vibrated directly.

Once the casting had cured a few more days. it was painted. And a nice brick red it is. The air bubbles still show, but aren’t discernable from a distance. The “Five Foot Rule” is in full effect on this first one, a learning experience for sure.

Another lesson learned is to wait until the casting is no longer “green”, that is, fully cured before fiddling with it… let alone flexing it or the exposed mesh along the edges. The missing edges where the casting fell apart because of that flexing are much more noticeable than those tiny voids in the brick face from the bubbles.

The Final Product

After painting, the casting was secured to the concrete block using thin set mortar. The missing edges were filled in as well, to look like a “repair” of sorts to crumbling bricks along the edge of the building. Now all it needs are windows for the upper floors and display case windows and an entrance for the ground floor.

Our First Building
Our First Building

All in all, our first building casting for the downtown marketplace is a success. Is it perfect? By no means, but it certainly looks more like a three story building than a bare concrete block does! Some “window dressing” and other details will make it an even more believable model.

Lighting is another consideration, and by extension, how to power the lighting. But all that will wait for another installment. We started working on the downtown marketplace back in June of 2019, so there is plenty more to come. Stay tuned!

If you have any questions, or you would like to see more detail, leave us a comment.