Planking a Wooden Model Ship or Yacht Hull

Planking is where a model ship hull starts to look like a ship. It is also where many builders get frustrated: planks that won’t bend, gaps at the bow, strakes that run uphill toward the stern. Most of these problems come from a few causes, and they can be avoided with some planning before the first plank goes on. This guide covers planking for both traditional ship models and model yachts.

Before the first plank: a faired frame

Planks can only lie smoothly if the surface beneath them is fair. On a plank-on-bulkhead or plank-on-frame hull, each bulkhead or frame edge has to be bevelled so a plank sits flat across it. A flexible batten laid over the frame should touch every station with no rocking, gaps or kinks. If you haven’t done this yet, start with our guide on how to fair bulkheads before planking a model ship.

Also check that:

• the keel is straight and the bulkheads are square to it
• the rabbet (the groove or step along the keel, stem and sternpost where the plank ends land) is cut or marked
• bow and stern filler blocks, if used, are shaped and faired

Why planks taper

Measure around the hull from keel to sheer at the midship bulkhead, then do the same at a bulkhead near the bow. The bow measurement (the girth) is much smaller. Yet roughly the same number of planks has to cover both. So each plank must be narrower at the bow than at midships, and usually narrower again toward the stern.

If you lay parallel-sided strips without tapering them, the strakes will either bunch up and need to be forced at the ends, or start curving upward at the bow and stern. A straight strip edge-bent hard enough to follow the curve may also lift or buckle.

Lining off the hull into bands

Lining off means planning where each strake will run before you cut any planks. A common approach:

1. Mark the sheer strake. This is usually the top strake, following the sheer line on the plan.
2. Divide the hull into bands. On larger hulls, use thin battens pinned to the frame to split the area between keel and sheer into three or four bands. Adjust each batten until it runs in a smooth, pleasing curve when viewed from the side, front and below.
3. Count planks per band. Decide how many planks each band holds, using the plank width at midships as a guide. Check references for your vessel to find a realistic scale plank width.
4. Mark plank widths at each bulkhead. Measure the band’s width at each bulkhead and divide by the number of planks in that band.

Measuring with a paper strip or tick strip

A strip of thin card or paper laid against a bulkhead edge makes it easy to record the girth of each band and tick off the divisions. Proportional dividers or a “planking fan” (a printed set of converging lines) let you divide any measured width into equal parts without arithmetic.

Preparing and bending planks

Most hardwood and basswood strips need some help to take a compound curve. Common methods:

• Heat with a little moisture. A soldering-iron-style plank bender, a hot clothes iron or a hair dryer, used with a damp strip, softens the wood so it can be pre-bent around a former or the hull itself.
• Soaking. Soaking strips in warm water makes them more pliable. Let the plank dry in its bent shape before gluing, or the glue joint may be weak and the plank may shrink back.
• Edge-bending vs spiling. A strip can be bent a little along its edge (edge-setting), but forcing it too far leads to buckling. Where a strake needs a strong edge curve, many builders cut the plank to a curved shape from wider sheet instead, a technique called spiling.

Tapering is usually done with a sharp hobby knife against a steel rule, then cleaned up with a sanding block. Builders differ on whether to taper one edge or both. Tapering a single edge is quicker, and the untouched edge stays as a straight reference against the previous strake. Tapering both edges spreads the change more evenly.

Laying the first strakes

Sheer strake, garboard, and working toward the turn of the bilge

Many builders hang a strake along the sheer first, then the garboard (the strake next to the keel). They then work alternately from the top down and from the bottom up toward the turn of the bilge, where the last planks are fitted. Planking alternately port and starboard helps stop the hull being pulled out of true.

At each plank:

• Pre-bend and taper it to the marks.
• Dry-fit it before applying glue.
• Glue to each bulkhead and edge-glue to the plank above.
• Hold it while the glue grabs, using pins, clamps or your fingers, and don’t move on until it’s secure.

Stealers and drop planks

Even with careful tapering, some areas don’t work out evenly. The stern of a full-bodied hull often needs extra width covered, and the bow often needs less.

• Stealers are short, wedge-shaped planks let into the strakes to fill extra area, usually near the stern.
• Drop planks go the other way: two planks narrow down and merge into one toward the bow.

Real ships used both, so they look correct on a model too, as long as they’re placed neatly and not too thin at the point.

Glue and fastenings

• PVA (white or yellow wood glue) gives more working time and allows small corrections. Many builders prefer it for planking.
• Cyanoacrylate (CA) is fast and useful for tacking a plank in place, but it’s unforgiving and can stain wood that will be varnished.
• Pins or small nails can hold planks while glue sets. On a single-planked or second-planked hull you’ll usually remove them, or use them only where filler or the second layer will cover the holes.

For the woods and strip sizes most often used, see our guide to model boat timber and planking supplies.

Double planking in kits

Many plank-on-bulkhead kits use two layers:

1. First planking: thicker, soft strips, often basswood or lime, laid to give the shape. Gaps and steps are filled and sanded fair.
2. Second planking: thin strips of a more attractive wood, such as walnut, sapele or mahogany, glued over the first layer and often left visible under varnish.

Double planking is more forgiving, because the first layer can be filled and sanded. Even so, the second layer still needs lining off and tapering to look right.

Planking a model yacht hull

RC sailing yachts and round-bilged power models are usually strip-planked rather than built like a ship model.

Strip planking with cedar or balsa

• Build a set of shadows (temporary moulds) on a building board, often upside down.
• Cover the shadow edges with tape so glue doesn’t bond the strips to them.
• Use narrow, uniform strips of light wood such as western red cedar or balsa.
• Start at the sheer or at a line where the strips run most naturally, and glue each strip to its neighbour along the edge.
• Many builders use cove-and-bead edged strips, or bevel the edges slightly, so the joints stay tight around the turn of the bilge.

Strip planks are usually left parallel-sided. At the ends, they’re trimmed to a line where the next strips can be fitted in a different direction.

Sealing a planked yacht hull

A strip-planked hull is not watertight on its own. Most are sheathed in a light glass cloth with epoxy on the outside and sealed inside as well. Our step-by-step guide to waterproofing a wooden model boat hull covers that.

Sanding and finishing the planking

• Start with a long sanding block and a medium grade, moving to finer grades as the surface gets fair.
• Sand across the hull diagonally rather than only along the planks, which helps level the plank edges.
• Fill small gaps with a fine filler or a mix of sanding dust and glue.
• For a varnished finish, keep filler to a minimum, since it shows.

Troubleshooting common planking problems

Planking takes patience, but each strake gets easier. Take your time with lining off and tapering, and the rest of the hull will go much more smoothly.