Iron the hull of your model ship

Almost ready to board your model ship? Not quite. Let’s end the discussion about framing. Before the columns and planks can be joined, all frames must be properly chamfered. This means that the outer edges of all frames are sloped to a greater or lesser extent to follow the course of the hull to provide solid support for the strakes. In English you say! Alright, the bulkheads amidships will be square but beveled towards the bow or stern in the direction of the bow or stern and the amount of bevel will increase as you get closer to either end. This is done so that the planks have the largest possible joint area with the bulkheads. The bevel angle is usually found on the waterline drawing. It is best to do some rough beveling work before attaching the bulkheads to the false keel so as not to loosen the entire hull shell during this process. Use a rasp or a long piece of sandpaper attached to a piece of wood. Once the bulkheads are attached to the keel frame, use some sandpaper to refine the angle.

Speaking of the waterline, make sure you have drawn the cargo waterline on both the false keel and the bulkhead. The waterline at which the loaded boat floats is usually not the same as the design waterline because boats tend to be trimmed aft and therefore the waterline is not parallel to the keel.

Start with the columns before any flooring. Columns are a series of heavy planks whose width may be the same as the hull but thicker so that they protrude beyond the plank. The top and bottom are usually slightly rounded and you can find more than one on a ship. Columns are used to provide additional support for the frame. When laying the braces, work alternately from starboard to port and make sure they follow the markings on the edge of the frame and have a smooth, even run with no flat spots or sudden bends. We now get into some fine detail when building 16th and 17th century ships versus 18th and 19th century ships. The former had columns that extended 3 to 4 inches beyond the floorboards and the latter 2 to 3 inches.

For the rest of this article series, I will speak in terms of an 18th century ship that was 155 feet long. The scale will be 1:48. Therefore, the actual length of the model is 38.6″. In the column protrusion example above, you would want the column to extend 1.5mm past the decking.

Now that we’re talking about scale, let’s look at the length and width of the boards used on an 18th century ship. The width was between 11 and 14 inches, which extrapolates to 7mm as the ideal scale width. The length of the boards ranged from 20ft to 24ft or about 5 ½” or 140mm scale.

The most common type of planking is carvel, where individual boards or battens are butted together. For modeling purposes, the most practical formwork method is to bond it in two layers. The first base layer will be a thicker piece of wood that will give the hull structure and shape (you can think of this layer as a practice board). The second layer is a veneer which is your finishing layer. For the base layer, you don’t need to worry about the length of the scale. To provide additional rigidity, you can glue pieces of wood between the bulkheads on the inside of the hull. There are strong curves both at the bow and at the stern. You want to preform the planks as best you can. There are several methods you can use, but they all involve water and a stencil. Soak your plank in warm water for ten to fifteen minutes. This is enough time to make the cells of the wood bend without breaking the cell structure. Place the wet wood on a template that simulates the shape you need and let dry. For very severe curves or extremely thick pieces of wood, you may want to go through this process several times changing the angles of the template as you go.

And now a few words about plank bending tools. The simplest template is the one made with plywood and nails. Shape the nails into a crescent shape and wrap with masking tape to prevent rust stains on the board. There are commercially available tools that do the same thing but are adjustable so you can change their angles. Another method is to use an electric plank bender. This is an excellent tool for thick pieces of wood. You will only need to process the board once and it will keep its shape. Some builders moisten the wood and hold it over a candle flame while they bend the wood. Others make a steam pipe out of a PVC plumbing pipe that is capped at both ends (one of which is removable). Whichever method you use, remember that if you use wood glue to adhere the board to the frame, you must allow the wood to dry completely because wood glue is water soluble (the key to success when gluing two pieces of wood together). An alternative is to use contact cement. The advantage of this glue is that the wood can be applied while it is wet and in its most malleable state.

The next useful step is to measure the actual travel of the planks on the hull. To do this, divide the hull at the midships frame into divisions the same size as the width of the planks. Now count the number of planks and divide each bulkhead into the same number of divisions. If the points thus marked are joined with a thin beveled batten, the exact course of the strakes will be obtained. At the ends, the boards should never be narrower than 3.5mm or wider than 10.5mm for a 7mm wide board.

Start applying the planks one at a time, starboard side first, then port side. There are a few methods you can use to hold the boards to the frames while the glue dries. There are lip clamps that screw or attach to the frame and hold the board in place. Since you are applying the inner layer, you can also use brass nails to fasten the board to the frames. The nail heads will be sanded down so you can leave them in place once the glue has cured. But the best technique is to apply a dab of CA (quick-drying) glue to one end of the board to lay it down, then apply wood glue to the rest of the board, turn on the TV to your favorite game, and while you’re having fun, hold the board. in place with your fingers for about 20 minutes. At the next commercial break, start with another plank on the opposite side of the hull. I estimate that in a 3 hour game, you should be able to apply 8 boards.

With the first coat, wood plank putty is now applied over the entire hull and then sanded. This is repeated until all cracks, gouges, dents and bumps have completely disappeared. Make sure the hull is symmetrical on both the starboard and port sides and check fore-aft travel.

Now it’s time to apply the finishing coating layer. For our hull sample, we will apply the veneer in approximately 5 section lengths. The usual pattern of changing butts is three shifts of planks or four shifts of planks. Just remember that butts always match frames. You may want to apply or simulate nails or spikes and you can also simulate tar lines between the strakes. Apply the veneer using the same methods you used to apply the first layer of planks.

Once the hull is planked, it is the ideal time to apply a finish. For unpainted hulls, you should use a semi-gloss varnish that has been thinned 30% for the first two coats and then unthinned for the final coat. Lightly sand between applications.

If you are going to paint the hull and before the ship model hull can be placed on a display stand, you must complete the underwater hull. First mark the waterline on the hull. Again, there are commercially available tools, but a block of wood with a pencil set at the correct height for the boat’s waterline works great. Just carefully wrap the piece of wood around the stationary hull. Below the waterline, the hull was usually painted with wood coal tar which colored it a dark brown or almost black. Sulfur was often added to tar to offer protection against worm attack. This resulted in a yellowish gray color. The alternative was to paint the underwater hull with white lead paint, which produced a dirty white finish.

From the mid-18th century, it became common to line the submarine hull with copper sheets. For our purposes, we will assume that our ship was built after 1850 and was British, so it would have a copper lining. Sheet size would have been 48″ x 15″ scaled to 25.4mm x 8mm with a thickness of 0.004″ To simulate nail fasteners, you can purchase pre-formed pieces or use cut-to-size copper strips and a wheel. 7/16″ jump to simulate nail heads. Copper sheets were usually overlapped from stem to stern and from top to bottom of the hull. So start at the bottom of the stern and work your way forward and up. Contact cement is good for adhering the plates to the hull. After installation is complete, clean them and apply a coat of clear protective lacquer.

Our next topic will be on deck decking.