It's high time I posted an update on the scrap tank, which is approaching completion. Painting started with a coat of grey Halfords primer from a rattle can. I then used the airbrush to spray the basic green colour all over. I find that Tamiya acrylics spray quite nicely, so I used a mixture of olive green and white, thinned about 50:50 with Tamiya's own thinner. This works for me spraying at about 15 psi (although I don't really trust the gauge on my cheap and cheerful compressor). After painting the basic green colour I used a brush to paint the black smokebox, cream cab interior, and various other details. I used enamels for the metallic colours. I carefully scraped the paint of the handrails to leave the bare steel colour.
Here are a couple of views of the body shell after both painting and decals. The latter are the waterslide transfers printed by Railtec from my design and now available from the 2mm Association. Before applying them, I (brush) painted the body with gloss Humbrol Clear, which I am told is similar to the old Johnsons Klear. After a couple of coats I thought I had ruined it with some ugly streaks etc. But I persevered and applied the transfers. I sealed them on with more Clear and finally a spray coat of matt varnish (aerosol of "anti-shine" from the Army Painter range). At this point, the ugly streaks miraculously disappeared, along with any visible transfer carrier film. So I was quite chuffed.
Next I turned to the chassis. The cylinder block was sprayed at the same time as the body, and below you can see it temporarily attached to the chassis for testing. Something you can see at the rear (to the right in the photo below) are the extra pick-up "skids", which I don't think I mentioned before. The design of the chassis didn't allow for the fitting of "Simpson springs", and I found that the current collection was dubious. Thus I fitted some phosphor-bronze wires with flattened ends that rest on the rail. I tried to disguise them to look like sandpipes from normal viewing distance. (Not as well disguised as the invisible brakes, however!) The skids substantially improved the current collection, and the loco now creeps along quite reliably on my test track. Time will tell how it performs "in the wild".
Once satisfied that all was running (i.e. after interminable fettling of slide bars, realising that one of the wheels was wonky in its muff so fitting a new muff, etc.), I soldered on the crank pin washers (from the 2mm Association etch) and cut off the excess length of the crankpins with the piercing saw. To solder on the washers, I used layers of Rizla paper soaked in oil underneath them to avoid gumming up the motion. Two or three layers seemed about right. It's important on this loco that the coupling rods don't have too much sideplay, as there is no washer on the leading crankpin and hence it would be liable to come loose otherwise. With hindsight I cut these front crankpins down a bit too much. You can see the different in the following (poor) view.
Here's a rear view. The cab windows (front and rear) were glazed with Micro Kristal Klear, a small bottle of which I have had for years. It's actually similar to PVA glue. What you can't see in the photo is that the loco is still missing any coal in the bunker, in which you can see the motor from above. You can also see the motor through the side of the cab, so I will probably cover it with black paper and fit a crew to further mask it. And I haven't yet fitted any couplings (functional or cosmetic!). The coupling hooks themselves were spare ones from a previous etch. I'll try to take some better photos at some point...