Luke Towan
November 2, 2023
7 min read

Dust Proofing a Model Railroad

Dust is a never ending battle for model railroaders!

If you look back through history there are many tips techniques and suggestions made by many different model builders and they all have their pros and cons.

The techniques I’m showing here are no different, while they may not be suitable for everyone they will at least get you thinking about how you to could make plans to control dust on your layout as well.

I’m sure I’m not the first to think of this as well, so if you continue reading I’ll step you through the process I’ve decided to implement to control the dust on my layout.

It starts right from the initial planning stage, this layout was designed right from the beginning with a dust mitigation plan consideration, the plan has been optimised gradually from its initial inception but the overall idea has remained the same.

Having the overhanging fascia on top makes the ability to close in the layout much easier, you could of course design a removable lid as well but for ease of use this worked best for me, it also give me a fixture for the lighting as well.

Now that I have a way to close in the front of the layout, I need to decide on exactly what to use. I’ve seen many people use tarpaulins which are a great cheap option but don’t really look nice, given that this layout will be seen every day I wanted a nicer looking option.

I’ve also seen curtains, similar to the curtains used to cover the layout supports however, while this looks nicer it still hides the layout from view. I actually bought some curtain material for this purpose however after sitting on the idea I decided to change the plan.

I finally landed on the idea of clear PVC sheet, this also went through a couple of iterations. First was thin PVC sheet that would act similar to curtain material… again after a test I wasn’t really happy with how it looked. Then using the thin sheet I made a frame and stretched it tight, this worked ok but the frame was a bit thick and took away from the clean look I wanted.

Finally I found some clear 3mm PVC sheet, the 3mm sheet is rigid enough to hold its own weight so it didn’t need a frame.

With that decided I just needed a way of fixing it to the layout, this process was straight forward and is shown in detail in the video. The main suggestion with using dowels to support the PVC is to ensure they are strong enough. I use 5mm thick dowel in the video which worked well, I probably wouldn’t use anything thinner than that, it’s better to be over engineered as opposed to having the dowel break and then have the PVC land on the floor and crack. The PVC isn’t cheap!

You should be able to find these at Bunnings if you live in Australia:

As for securing the sheets, magnets work just fine. I chose to only use magnets on one side (ie the magnets are attached to the PVC sheet) and screws on the other. I did consider using magnets on both sides (ie magnets instead of the screws) but they were too strong. I was concerned that after a while the magnets would pull away from either the fascia or the PVC mount that I had laser cut.

Also shown in the video, I fill in all the gaps within reason. I didn’t go overboard trying to make it air tight but I did spend quite a good amount of time filling in whatever gaps I could see.

The main concern is having airflow enter the layout through the top filters and then flow straight through and out the gaps in the bottom of the baseboard. This has the potential to create a Venturi effect and subsequently suck air in through the front of the layout.

This would literally have the opposite effect from what I was after! So that’s why it’s important to seal up any obvious gaps, however you want some gaps, because the air that is getting forced through the filters into the layout has to go somewhere and if it’s too airtight it might cause one of the PVC panels to pop free and land on the floor.

The DIY filler I use worked really well, it’s not the most cost efficient filler but it worked and it worked exceptionally well. You could also use any sort of general filler putty or caulking but just make sure it’s foam safe if you are using it on foam and you also want to try and find a filler that has minimal shrinkage, although if it does shrink you can just apply a second coating until the gap is filled.

Some gaps are covered using masking tape, specifically along the top where the LED light panels are attached. I chose to use masking tape here because the LED panels need to be removable and there are wires that potentially will inhibit the foam if I was to use larger pieces of polystyrene to fill the gaps. The tape can be removed and replaced quite easily should I need to change the LED light panel at some point.

The last effort to stopping dust is the filter. This is a laser cut design and is made in such a way so that air can be drawn in, filtered and then pumped into the layout from the top. This filtered air will then flow in and fill the inside of the layout, as more and more air gets pumped into the layout the excess air has to go somewhere.

This excess will then flow out any remaining gaps, like the gaps in the PVC sheet and any other small gaps around the layout. This outflow of air from the gaps means dust won’t be able to enter in through those gaps, so as long as the air being pumped into the layout is clean and dust free then the layout should be able to stay clean.

A couple of considerations to think about, as mentioned earlier we don’t want it to be too air tight because the air being pumped in has to be able to escape. Additionally we don’t want to suck dusty air into the layout, which is why the fans have filters but also they are mounted up high on the layout. Lastly the fans are running at a very low voltage, this is because we only want a very gentle flow of air.

Even though there is a filter, some dust will still make it past and if we are pumping huge amounts of air through then more dust will eventually make it through the filter over time, so by only having a very gentle flow it will mean less air volume and thus less dust in the long term needing to be caught by the filter and also the slower flow of air will give the filter a better chance of catching that dust in the first place .

A comment that was mentioned in the video is about using a HEPA filter, these are designed to catch dust and would make the perfect filter to use, or what I’m doing now is to use a piece of vacuum cleaner bag cut to size so a sheet of the bag paper would fit under the spray booth filter I’m using. This will ensure almost no dust gets into the layout!

Laser cutting and 3D printing is a bit of a controversial subject when it comes to model building, I often get comments about using expensive tools like these. While that is true, they aren’t cheap, they are also an investment that will save money and time in the long term. They are also getting cheaper by the year as they become more popular, I’ve seen good resin 3D printers for as little as $200 second hand and some laser cutters are getting down to the $600 - $700 range.

If you look online you’ll also notice many manufacturers are making and selling 3D printed details, like 10 oil drums for $10, this seems cheap but imaging you could 3D print hundreds of these for just a few dollars and you’d quickly make you money back that you spent on the printer… Plus you’d have a 3D printer! You can make thousands of layout details for a fraction of what it would cost to by them commercially.

It’s just something to consider.

You also have the option of using a laser cutting and 3D printing service like shapeways, so it’s not out of reach to the general modeller.

If you want to try making one of these filter boxes I’ve made the files free to modify on TinkerCAD, it’s the main project file so you can open it up and play with the design to fit your needs. Here is the link - https://www.tinkercad.com/things/4sm4iH7blc7

I’ve currently got the system running with some black panels both inside and outside the layout, I’m doing this so over the next couple of weeks while nothing is happening with the layout I can test just how effective the system is, I’m always cutting wood, painting and making a general mess in the garage so it should be a good test to see if all the effort was worth it in the end.

In the next update I’ll be adding the backdrop, this will make a huge change to the general appearance of the layout. I’ve got a few things to consider so if you’ve made it this far down the article please feel free to share any tips or advice you might have for how the backdrops should be added, I can certainly do with all the tis I can get because I’ve not installed many backdrops.

I’ve helped friends with their but as for myself, it’s new territory.

Thanks for reading and I look forward to reading your comments.

Downloads:

Download the files associated with the project. All files are included in a zip for convenience.

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