November 2013 Status

Work on the layout pretty much didn’t happen in November. Partly that’s down to other distractions, and partly because I was trying to work out how to paint things in the winter, since my usual method of spray-cans depends on the outside air being above 50°F (10°C). And, unfortunately, most of what I’m doing now depends on painting models.

Even the “one point five meter line” needs the station building painted before I can lay track, and I didn’t get that done in October before the weather turned cold.

I spent much of November working out what to do about a new airbrush, with the intent that I’d use some indoor-safe paint with it. The problem I ran into there, which finally brought everything to a crashing halt, was that there’s really no such thing. All of the paints I’d like to use probably requiring thinning (I really have to try an experiment with non-thinned acrylic though) and may of the “water-soluable” acrylics use alcohol as part of the formula. And both of my likely painting locations are near ignition sources (gas stove in the kitchen, furnace or water heater in the basement). Use of anything that puts a flammable liquid in the air isn’t in my plans.

I may figure out some way to rig my spray booth in a bedroom with an exhaust tube to a window. That will allow painting away from flames and vent any potentially problematic substances outside. This will require some planning, and a bit of carpentry, so it hasn’t happened yet.

But for the moment, I’m a bit stuck.

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.