Nov 2013

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.

October 2013 Status

Another month, and nothing much to show for it.

I spent the first part of the month working on the software for the Tram Controller. Then I got tired of that and set it aside.

Next I spent some time thinking about the track on the One Point Five Meter Line layout, and what to use for the station at the Urban end of that, and the platforms. I documented that in previous posts.

And then I hit a wall. I just stalled out for a couple of weeks. I didn’t really want to work on the software. I spent some time playing with occupancy detector circuits on paper, but never got around to building one (that is still something I plan to do). I thought about the scenery and buildings for the One Point Five Meter Line, but didn’t actually DO anything. I did some maintenance on the website. But all in all, very little happened.

After a hiatus, I started thinking about structures again, and I may get back to working on those shortly. But October was a “nothing much happened” month for me, as least as far as model railroading goes.