Flying boats and seaplanes on a shelf

Flying boats and floatplanes are the most rewarding aircraft models to display and the least forgiving to assemble. The reward is that a hull gives you a context no landplane has. The difficulty is that everything hangs off struts, and struts have to be right in three axes at once.

Three ways to display a hull

Most collections end up with one of each, because the three modes look different enough that they do not compete for attention on the same shelf.

Alignment is the whole game

Wingtip floats, sponsons and engine nacelles all sit on struts, and a strut glued a millimetre out at the root is several millimetres out at the tip. The method that works is unglamorous:

1. Dry fit everything before any cement touches a joint. If a strut does not sit in its locating hole under its own weight, open the hole rather than forcing the strut.
2. Build a jig from a flat board and two blocks of scrap. The hull sits between the blocks, so it cannot rock while glue sets.
3. Glue one strut at a time, and check after each one from directly in front at eye level, then from directly above. Those two views catch every alignment error there is.
4. Let each joint cure fully. Liquid cement is soft for far longer than it feels, and a joint tweaked at the wrong moment stays tweaked.

The same discipline applies to biplane and rigged aircraft, where it matters even more. See the early aviation page for the rigging order that makes it survivable.

Chines, spray rails and the planing step

A flying boat hull is a boat first. Three features do the work, and a kit that moulds them crisply is worth more than a kit with extra rivets:

• The planing step, the sharp break in the underside partway along the hull, which lets the aircraft unstick from the water.
• The chine, the hard edge where the bottom of the hull meets the side. It should stay a crisp line all the way forward, and it is the first casualty of over-enthusiastic sanding.
• The spray rails, thin strips along the forward chine that throw water down and away from the propellers.

When you sand a hull seam, sand across the chine as little as possible, and restore the edge with a sanding stick used flat against the hull side rather than rolled around it.

These aircraft are bigger than people expect

A Sunderland at 1/72 is half a metre across and, on a water base, needs a board wider still. This is the one branch of aircraft modelling where 1/144 is a serious option rather than a compromise, because the shapes are large enough to read even when small.

Water bases without the mess

Three approaches, in order of difficulty:

• Painted board. Hardboard or MDF, sealed, painted in three or four blended tones, then given several coats of gloss varnish. Cheap, flat, and convincing at normal viewing distance.
• Glass with painted underside. A sheet of glass over a painted board. The depth of the glass gives real translucency, and the surface is genuinely smooth.
• Acrylic gel medium. Clear gel, textured with a stiff brush while wet, then tinted and varnished. The only method that gives real relief, and the only one where restraint matters: scale waves are much smaller than instinct suggests.

Whatever the method, keep the water low. A hull sits in water, not on it, and the most common mistake is a wave height that would be three metres at full size.

Weathering a hull that lives in salt

Salt water leaves specific marks and only those marks. A scum line at the waterline, slightly ragged and darker on the shadowed side. Bright scuffing along the chine and around the step, where beaching gear and slipways rub. Exhaust staining behind the engines, running back over the wing rather than the hull. Restraint is the whole technique: three subtle effects read as a working aircraft, while six read as a wreck.

Waterline model

A model cut off at the level the hull would sit in water, so it can only be shown floating.

Planing step

The transverse break in a hull bottom that lets the aircraft break free of the water on take-off.

Sponson

A stub wing or fairing on the hull side that gives stability on the water. Dornier types are the obvious example.

Beaching gear

Removable wheels clamped to a flying boat hull so it can be pulled up a slipway. The reason a beached model looks convincing.