SCRATCH

THE ROAD TRAVELED TO MAKE THE WEAKEST AND BRITTLE PARTS ARE THE STRONGEST.
The brass is the metal most used in modeling. Cheap and with a hardness between aluminum and steel. Easy to cut, file and bend like aluminum, but much harder and more torsion resistant.This allows to make firm and durable structures easely. Unalterable for decades and even centuries.
The new plastic retains some flexibility that saves it from damage. But after a few years it loses properties becoming rigid and brittle, breaking easily in fine pieces. Brass sheets allow for thin, hard and durable parts without worrying about years.
The brass allows to use rigid sheets of very thin thicknesses. Much more of what the plastic can imitate. This is a Sukhoi 27 ammunition container loader. It would be very difficult to make such thin walls out of plastic. And even it was, no one would bet on it not being deformed or broken over time. This brings an advantage of realism that puts these models to a higher level.
Used in the visible details, the very thin thickness of sheets and tubes are infinitely more realistic. And being plates or tubes manufactured with industrial methods is ensured the cleanliness of their forms. An observer wouldn’t know why, but he feels the degree of accuracy is much higher. The cause is very simple. No deformed or abnormally thick surfaces out of scale due to plastic limitations.
The drawback of brass is that it is necessary to use soldering iron and tin to join the parts together. But for extraordinarily small parts, tin leftovers will have to be smoothed, and sometimes it is not possible to re-weld without melting welded joints of very close parts. This is the landing gear of a 1/48 scale AVRO Lancaster. The weight of the model, complexity of the train and the fineness of the straps, recommended the use of metal to ensure robustness and lonjevidad. It is unfortunate to repair models past years.
Coincidentally 2 years after taking these pictures, this Lancaster was bolted down the bottom of the wheels to a diorama. And accidentally the diorama fell to the ground from a height of 1 meter. With plastic this blow would have meant the explosion and breakage of all the thin plastic straps making the model irreparable. However, even though the impact was tremendous chopping one of the metal screws to one wheel, only the other landing gear that remained fixed to the diorama was broken. And just pipe a fracture at the point where the plastic shock absorbers attach to the landing gear made of brass. This is... the glue point.
As can be seen on the landing gear, the thin straps in "V" are firmly attached. As mentioned earlier, the problem came in the small panels that serve as a guide and protection for the kneecap dampers. These panels of just over 3 mm. are made with brass sheet, welded to 2 wires of brass. Soldering these 3 micropieces welded together to the main tubes was not possible without the joints unraveling. What to do ?
The solution, although only for these small parts that do not withstand force, is to use elastic resin. The metal contracts and dilates and therefore rigid glues such as cyanoacrylate cannot be used. The glossy enamel paint works very well because of its high concentration of flexible resin. When it comes to painting, it attaches very well to brass. And the resin acts as a glue with a perfect elasticity / rigidity ratio.
Small details sticking out of a structure are always a risk of breakage. And over the years they are very difficult to repair. They will almost certainly split, forcing you to build a new piece from scratch. The photo shows the aerodynamic counterweights of a tail rudder. Made with steel thread welded to a tear sculpted in solid brass tube.
It is important to dig a good notch into the plastic to fix the metal well. Cyanoacrylate is not reliable. Epoxy is more durable. It could still give way in an accident by separating metal from plastic. But the metal piece will hardly break. The details are therefore realistic and time-resistant. And in the event of separation, only the part can be re-glued.
Another good exponent of the use of brass, are the straps of the tanks of this tank T-34. Originally they were a false relief on the cylinder of each deposit. As evident as they were ruinous by the sense of artificiality. Making them with thin plastic would have meant a safe break. We’re talking about a thickness of about half a millimeter. The solution, brass foil.
It also allows to bend it safely with tongs to make the crimping with the link, made of metal thread. Brass has allowed these supports to be tightened thoroughly without fear of breaking. Imitation ends up becoming real miniature tensioners. Better than a photoetch purchased from a specific manufacturer, and for a minimum cost.
Another case is these radar antennas from a Heinkel 219 UHU to 1/48. As fine as they are condemned to break at the slightest snag with a garment or a cleaning cloth. The solution, sanded steel pins to remove chrome, and tip them on both ends, welded to the brass frame. You can also see the landing gear that was made of brass and steel.
All of this was practical to see how much detail can be achieved with brass. And the answer was clear. Brass is exceptional. And it’s perfect for reinforcing thin pieces. But it’s very difficult to model to make details of very few millimeters. So we came up with a solution that we put at your disposal.
Brass embedded in SLA 3D resin parts. As you can see, this landing gear of a 1/32 Mirage IIIE had to support the weight of another heavy model. The breakage points would undoubtedly have been the piston of the shock absorber, and the side straps. However contrary to the Lancaster case of the above example, details of a modern landing gear are required. With many ledges and details of very varied forms.
So our solution was straightforward. Use the unbeatable detail quality of 3D resin, adding the structural strength of well-fitting metal tubes inside. For this, the 3D design was tested until a very precise fixation was obtained with brass tubes at scale. This gives the best of both worlds. The parts remain very difficult to break by the weight of the model, and higher levels of detail.
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