Wednesday, February 17, 2010

Taming Brass

I had something of a pleasant surprise today: my latest AFV is decked out with photoetched brass, something I would never have expected. Brass has never behaved for me and I didn’t expect it to this time. But… That Trumpeter M1126 Stryker came with a beautiful fret in the box, and I thought I might as well give it a shot, as there were alternate plastic parts if the brass wasn’t cooperative.

I’ve used PE before, of course, I’ve added screens and grills on three previous models, but folding brass has so far defied me. Maybe I started out on the wrong foot… The Airwaves set I picked up for my Academy Merkava II was simply too hard to fold with the old standby, two single-edge razor blades, and I had not heard of the annealing trick at the time, so the PE more or less ended up back in the packet with a big question mark hanging over it.

With those memories, I approached the Trumpeter brass with trepidation, worked on basic theory and gave it a go, open to the possibilities but expecting nothing in particular.

Well… It cut where it was meant to cut, filed where filing was necessary, and folded where folding was called for. In moments, it seemed, some very tidy brass structures were on my bench. The only pain was the pedestal for the forward wire cutter which did not match the size of the recess in the hull, which needed filing out to accept it, and that may have been my fault for folding into the guides in the brass, instead of away from them. No matter, the fit was quickly adjusted with files. The only brass part for which I opted to use the plastic instead was the small shield part that goes behind the weapon station on the commander’s cupola, and that’s because the component is simply the wrong size. The plastic part fits (and was moulded remarkably thinly), the brass part never will. Similarly, the support under the starboard jerry can holder will also simply not fit: the locator slot is set too far back, the fold points result in a structure that would hold the rack away from the hull if located there. I filed the tab away and tried again but the support structure interfered with the plastic components directly below. The plastic equivalent was moulded as part of the plastic version of the rack, and I considered cutting it away… Another option would be to scratch the support from some light stock, which may be the easiest route.

I found something of a lesson in this; one automatically assumes that hi-tech metal parts must be “better” than the plastic ones, but their accuracy can only be as great as the information on which they are based, and if they are the wrong size or shape they will never fit properly, no matter how sophisticated their manufacture.

The cya bond between brass parts is surprisingly quick and strong, but the bond between brass and plastic seems lamentably weak: this model must be handled with the greatest care. If the brass parts, with the exception of the securely-snugged-down engine grills, end up falling off, I may retro to the plastic parts in the end, but the experiment has been very much worthwhile.

All told, I feel more charitable toward photoetch today than before. It’s a learning curve, for sure, to fold and trim tiny pieces of brass and steel, and I don’t see myself ever using much of what’s out there, especially when it crosses that line between adding necessary detail and “gilding the lily,” or what’s worse, overcomplication for the sake of it, but I can certainly see myself using etch at this level, to reproduce scale thickness and make from fine sheet metal those structures which are made from light sheet metal on the real deal.

I don’t for a moment consider myself a brass-tamer yet, another few successful metal detailing outings and I might start to think of myself as one, but I’ve made a start… I find myself thinking about that Lion Roar set of turret armour for late Panzer IVs I picked up last year, and can actually see me getting my clumsy fingers around the job after all!

More on the Stryker when the paint goes on.

Monday, February 15, 2010

Monochrome, and When It Isn’t

There are some techniques that “take a bit of getting comfortable with,” and some that take a bit of nerve to try out. Pre- and post-shading I’ve not yet given a whirl. The idea of blacking the panel lines of an aircraft to show through the actual colour coats as a subtle shadow around the lines, like a dark halo to each side of the final line accent, is a great one, but it takes a surprising degree of guts to try it out, when models already come out pretty good on less drastic techniques. And as for post-shading, even after 31 years of air painting, I don’t trust my airbrush not to make a mess at the last minute…

I started fading paint on the top surfaces of tanks about two years ago, and I’ve faded seven models so far. Mostly disruptive schemes with dirt and rust on top, the fading is subtle and delivers a pleasing effect. For only the second time I’m doing a single colour vehicle, and the fade-and-shade routine seems to be becoming more natural, just a part of the process.

The shot above is an overview of Trumpeter’s 1:35 Strv 103B, Sweden’s famous “S-tank,” the only fixed-gun MBT to see service. I’ll review this very good kit fully when it’s finished, for now I’d like to talk about the process of fooling the eye with the paintwork.

I mixed the base colour from Tamiya acrylics and got a good solid coat on, then mixed a batch lightened with a 20% addition of white. It took this much to get a visible result, the green was a powerful pigment. I laid this mixture on, well thinned, with subtle spotting and stroking in the centre of panels and areas, the typical pattern for sun-fading and general wearing away of paint. Then I mixed some more and darkened it with a 20% addition of black, and applied that to the undersides, the hull behind the running gear, under the bow, tail and stowage bins, and under the topmost portion of the dozer blade, the idea being to encourage the eye to see shadow where shadows would most naturally fall.

The photo is taken at this point, and the variation in tonality is actually more visible in the image than it is to the naked eye. The next round of work will be oil pinwashing followed by enamel drybrushing, my standard armour finishing process, and I expect the overall effect to blur together into a pleasing optical illusion.

Do real tanks display fading this way? Peacetime tanks that get regularly serviced? Maybe not, but the eye tends to expect these tricks, and when you get used to them, a model finished in parade-clean condition has the disturbing quality of a toy. Tanks should be dirty, they should be rusty and their paint should be faded by the elements in which they serve, and this logic has created a suite of visual queues without which armour models don’t seem quite right. This is not really true, certainly not all the time, but that’s maybe the theme for another post entirely. The question is whether you can paint a model one colour overall and have it look convincing to the naked eye.

I would say probably not. So long as it is subtly done, the fade-and-shade routine automatically imparts a tonal gradient between highlight and shadow which are close but perceptible, and provide a narrow “reference range” against which the much starker contrast of the dark pinwash in corners and angles around details, and the light drybrushing that profiles the sharp edges of structures, become part of an overall spectrum of tonality that tie the model visually together.

That’s the theory, it seemed to work on the Japanese Type 74 I featured back in the early days of this blog, and I’ll know pretty soon if it works on the Strv 103B. My next project up is Trumpeter’s M1126 Stryker, another monochrome subject, and I’ll do it the same way, with one extension: I’ll use the darkened version of the base colour to generate a soft post-shade effect around all the divisions in the Stryker’s external plating. Combined with the fade coat applied to the middle of all the panels, this effect will either look great or like a patchwork quilt (in which case I’ll zap on another coat of NATO Green and start again…)

I’ll sequel this post with another look at the “triple-value monochrome” trick when I do that job, and there’ll probably be something soon about natural metal finishes for aircraft, if the approach I’m trying on a Tamiya F-84 works like it should…

Friday, February 5, 2010

Now That’s What I Call Shelf-Life

I have rarely had cause to need gold paint. I have always fancied doing that gold-painted F-16, Sioux City Special I believe she was called, I even have a kit and decals lined up for the day I have the time... The chance... Somewhere to put it... But the odd gold detail might call for having gold in stock.

I have a tinlet of Humbrol #16, Gold. I recently needed to open it for a few dabs of gold to visually blend in some gold foil I was applying, and sure enough, there it was, in the box at the back of the drawer. I really don’t remember if it was ever opened to do a job, but I am sure it was bought to do the gold detail work (engine accents, IIRC) on a small kit of the Honda CB 1100R motorcycle, by a firm called Crown.

I bought that kit around Christmas 1982, it may be the oldest single article in my stash (still unbuilt). And by default, that means the paint is now around 27 years old. (The pic above is a new tin, I can’t seem to lay my hands on the old classic…)

It wasn’t even thick in the tin. I gave it a shake, opened it and stirred it for thirty seconds, and it was good to go. When that paint was manufactured, that expression wasn’t even in use, nor were in the pipeline, 24/7, on track or my bad. That’s what you call shelf-life! Maybe the pigments weren’t as finely ground in those days, and the available ranges were smaller, but the chemical balance of the paint in the tin makes for a virtual time-capsule: so long as the balance remains within certain margins the mixture should remain viable forever.

Of course, there are other tins that go hard while you look at them, and I had a bottle of MM enamel whose contents turned into a strange, rubbery substance without ever being opened, or maybe only for a tinting dab, but this is where chemistry meets philosophy. The same thing happened recently to another bottle, much newer, something to do with failure of the foiled card seal in the cap, I think. Folks have been complaining on other forums about this and other shortcomings of the Model Master range, lately, which is a pity as it’s really good paint, just let down at times by packaging issues (and accuracy issues, like the identification numbers of the RLM 82 and RLM 83 shades somehow getting reversed when the labels were printed… Or their Dunkelgelb being a bit on the dark side…)

For the moment, I’m very impressed with Humbrol. Of course, the delicate balance of chemistry in the tin has been disturbed now, and the next time I look at it, it may have congealed, disintegrating like a vampyre whose coffin was opened before dusk. I guess we’ll see when it comes time to build that F-16 (unless I’ve graduated to Talon Acrylics by then...)