Storing Rail


As I’ve mentioned previously, I’m going to be hand-building turnouts for the new layout, and possibly also hand-laying some of the track, although I’ll mostly use flex-track. But this means that I need to buy bulk rail. I’ve actually done this in the past, and one of the problems I’d had was that rail is easily bent. And once bent, it’s generally not usable. I needed a place to store rail where it could be kept straight. And I was likely to have more than one rail type or size, so I also needed a means to keep the different kinds separate.

A friend suggested PVC pipe, which turned out to be a very good idea. A quick trip to the local hardware super-store revealed that 3/4” PVC pipe looked like a good size for storing a bundle of rail, and it comes in ten-foot lengths, which evenly subdivides into 40” lengths that will hold either 36” or one-meter (39.37”) lengths of rail. The store would even cut it for me. A solid cap on one end, and a threaded fitting on the other with a screw-on cap completed the design. I’ll probably eventually build a wood frame or rack to hold several of these tubes on a shelf or wall.

If I were hand-laying track and buying in large quantities, I’d probably use larger diameter pipes to store it. But for keeping a dozen or so rail lengths on hand for turnout assembly, this is a good size, and it limits the amount of motion the rail can have. I could have left one end open, but having a cap means I can carry the pipe around with rail in it. For example, I expect I’ll take these to the store when I buy rail, and transport it home in them, to avoid any risk of in-transit damage.

Note: like many things in the construction industry, pipe dimensions are misleading. A 3/4” pipe per “schedule 40” (what I bought) has an outside diameter just over an inch, and an inside diameter of 0.824” (20.9 mm). If you buy schedule 80 pipe (which apparently is gray rather than white) in the same size, the inner diameter is 0.742” (18.8 mm). Those inner dimensions are also “typical”, and I’ve seen other numbers listed for them. Finally, there are also some specialty types with other dimensions, but these are the two common forms. The exact diameter doesn’t really matter, but more is better for a storage container, so I recommend the white pipe.

Detail of end with pipe fitting

Gluing them was straightforward, but used a MEK (Methyl Ethyl Ketone) cement (technically a solvent, like ordinary plastic glue) that contained acetone, among other things. Very nasty stuff. I did it in a friend’s garage, with the window left open, using a “low VOC” formula, and even the next morning the odor was still strong. By 24 hours the odor was mostly gone. For a more detailed description of gluing PVC, there’s a good Instructable here.

Ideally you should clean and prime the PVC before applying glue, but since I don’t care about maximal structural strength or being water-proof, I just wiped dust off the pipe and applied the cement directly to both parts where they would touch. Work on one part at a time, and work quickly: you only have about 20 seconds after application before it dries (less in hot or dry weather). If there’s any force pulling the parts away from each other, hold in place for 30 seconds until it sets. The base cure time is 2 hours, so I did one end of each pipe and came back two hours later to do the other ends, so any fumbling about wouldn’t dislodge the first part.

MEK, as mentioned, is nasty stuff (see my Material Safety page for more info). You don’t want it on your skin, so wear disposable nitrile gloves. And even the fumes are considered to be carcinogenic, so you don’t want to breathe them. Use it outdoors or in some place where the fumes won’t get into the house (a shed or garage) and leave it to cure. And keep it away from anyone pregnant. And, of course, don’t eat, drink, or smoke while using it. Particularly the latter, as it’s highly flammable. Very nasty stuff.

Although cure time on the jar is listed as “2 hours”, it actually varies by the size of the joint. You can find cure-time charts by searching online. The one for my brand of glue noted that for a joint my size, at 20° to 40° C, typical cure time was 6 hours, but a full (180 psi) cure took 36 hours. These increase with humidity above 60%. I left the finished parts in the garage for a couple of days so they wouldn’t smell up my train room.

I may paint these, either to color-code different types of rail, or simply to make the shop look nice. Painting PVC is fairly straightforward, simply clean it with window-cleaner (anything with ammonia), sand lightly with 220 grit sandpaper to give it “tooth” for the paint to grip, then wipe any dust off with a damp cloth. Finally, spray it with a plastic-compatible paint. I’d probably use spray cans, as these won’t fit in my airbrush spray booth.

Multiple coats will likely be needed for a solid finish, and these need to be applied after the paint has partially dried, but not before it sets (somewhere between 30 seconds and 5 minutes is probably good). Otherwise you need to wait a week or so to recoat to avoid crazing (cracks in the paint finish). Times will vary by brand.

Pro-tip: when painting, leave the cap off (you don’t want it painted on), wrap masking tape on the threads so you don’t gum them up, and stick a dowel inside the tube to use as a handle so you can paint the whole thing. I’m still working on what I’d use to hold the dowel while the paint dries. Maybe a board with holes drilled in it.

The parts cost excluding glue was US$10.20, and the glue sells for about US$5 for an 8 oz jar (good for about 275 joints; far more than I will ever need). So for about US$5 each, and about ten minutes of work, I now have three one-meter rail storage tubes. I expect I’ll make more of these.

Thinking About 3D

I read in a recent newsletter that the NMRA is currently grappling with the issue of how to judge “scratchbuilt” models that were made using parts from a 3D printer. The issue for them is how to fairly judge when someone creates their own parts versus simply printing and assembling designs made by others. My two cents is that this shouldn’t be too hard, since the issues are exactly the same as use of commercial castings (e.g., for a window frame) versus making your own from strip styrene or similar. There is an honesty aspect to it: someone could lie about their source. But you could address that by requiring the modeler to submit their part files as part of the entry process if they claim to have created them. It’s important not so much for the issue itself, but rather as the author of that piece noted, as a measure of how technology is changing the hobby.

Kato DC Power Pack

Several years ago I investigated several DC power packs, including one of my Kato packs (I have three of them). At the time I was reluctant to take one apart because the screws are hidden under the glued-on feet. But a question on the JNS Forum spurred me to investigate the circuitry more closely, and so I took one apart. And in the process, I discovered that some of my old information was wrong.

Airbrush III - Plan A

Before every “Plan B” there is a Plan A. I have a sneaking suspicion that I’m not done yet, but I decided I wanted to try a Plan A that might cost a bit less than where my thoughts had been heading. So the idea is to see just how well my decade-old 20 psi (1.4 bar) Badger compressor would work as a supply for a simple, bottom-feed, wide-nozzle Paasche airbrush spraying modern acrylic paint.

I’m not expecting much, honestly. The bottom-fed airbrushes are reported to need a lot of air, since they have to suck the paint up rather than letting gravity feed it from below. That’s probably why they have large nozzles: medium on this is 0.7 mm, roughly twice the diameter and 4x the area of a medium nozzle on a gravity-fed airbrush. And acrylics are likewise noted for being heavy, and needing more air to spray. On the other hand, they throw a wide spray of paint, and for the kind of priming and color-coating I’m going to do, at least initially, that’s what I want to have. And some online info suggests you can paint with this stuff, suitably thinned, at pressures below 20 psi.

Airbrush II - Hoses and Adapters

The first airbrush was patented in 1876. You’d think after 137 years people would have figured out one “right” way to hook one up to an air supply. Alas, “people” are never that sensible.

In the course of researching airbrushes, I bumped up against the fact that there are a number of different methods for connecting airbrushes to compressors, using different sizes of connectors and incompatible connectors of the same size. Some of these are multi-vendor, some appear to be unique to a single vendor. Most appear to derive from national standards from wherever the airbrush is made, or marketed.

And they’re not well documented: you’ll run across terms like “Badger adapter”, but adapter from what? I decided I needed to figure out just what was in use. This plethora of connectors apparently wouldn’t keep me from mixing any airbrush with any compressor, but to do that was going to require knowing what kinds of hoses or adapters would be needed. Plus, thinking about this gave me more time to let the question of “which compressor and which airbrush” bounce around in the back of my head.

Airbrush I - Compressors

About fifteen or twenty years ago I bought my first airbrush, I forget exactly when. It was (and still is, see above) a Badger 350 (current retail about US$45). Shortly after, I bought a cheap, simple compressor: a Badger Whirlwind 80-2 (no longer sold). The compressor puts out 0.4 cfm at 20 psi. It wasn't really a very good choice of compressor, being both noisy and underpowered, but it served well enough for what I did, at least at first.

An airbrush is a very useful tool for modelers, and you don't need to be an artist to use one (I certainly am not!). My first use was to paint the rails of my HO flex-track "rust" after it was nailed down to the cork (yes, I was still using nails). To do that you just spray a 2" (5 cm) wide swath of color before ballasting, masking off whatever you don't want painted, and then wiping the tops of the rail with a cloth lightly soaked in thinner before the paint can set. I had to mix my own rust color, which turned out to be easy. The 'brush worked so well, and so intuitively, I was sold. I also used it for painting large swaths of color on plastic buildings.

A Clean Track is a Happy Track and February 2013 Monthly Status

Track gets dirty. Cleaning track is a nuisance. But if you want trains to run reliably, it’s an essential nuisance.

My layout is in an unfinished basement, with lots of boxes and other junk that collect a fine layer of dust, not to mention exposed joists with insulation, and power tools that kick up their own dust from cutting wood. A drop ceiling, drywall, and tile floor around the layout would be nice. But it’s not very practical in this basement. Maybe in a future basement...

So I clean. Often.

Work Table and March 2012 Status

Work on the village buildings continues, although it’s been slow recently due to other demands on my time taking me away from layout work. This weekend, however, I found time to build a small work table. Read More...

Not Your Every-Day Power Tool

As I mentioned a couple of weeks ago, I’ve been waiting for a new saw to continue work on the Expressway. It arrived this week, and while I haven’t done much with it yet, what I have done is living up to my expectations. The saw, shown above as I was unpacking it, is a Byrnes saw. This is made by a modeler, for modelers, and intended for accuracy, as well as the ability to cut small pieces of wood or plastic (with the right blade, thin aluminum, brass or other soft metals would probably be fair game also). It’s not cheap, but it’s worth the money, at least to me.

The top is machined from a chunk of aluminum 10” x 12”, and the base appears to be aluminum also (as are the bulk of the accessories). Several options are available: I added the extension to the rip fence (above to right of blade) that makes it about 1/2” thick instead of just a few mm (this is removable) and added the extended-length arm to the miter (seen taped down above). I also added the metric version of the micrometer (right corner) that can be used to advance the fence for cutting precise-width strips of material, and I bound the “Rip Taper Jig” which is another accessory for holding things at a specific angle for cutting.