BY WILL STIRLING

Making and fitting a boat’s shutter planks can be awkward as there is no room for error and a good deal of room for gaps. The secret to a fag-paper fit is in careful preparation. The following, fairly foolproof, method is known as the ‘tad-nab’.

1 First, make a pattern of the inside edge of the plank. Do this by laying a strip of thin plywood into the gap along the hull and tacking it onto every other frame. You may have to use several lengths to cope with the shape. Cut up some more plywood into oblongs of around 6in by 3in (150mm x 75mm). Work along the bottom of the gap, attaching these oblongs (the tad-nabs) to the length of plywood so that they touch the plank edge at 12in (31cm) intervals and with two pozi-drive screws so that they cannot pivot. Work along the top of the gap at similar intervals. Make sure that the tad-nabs are fitted to the inside of the plank edge. Climb inside the boat, mark and number each station.

2 This is your ‘spiling board’, which must be carefully removed and laid on the planking stock. Lay it upside down (inside uppermost).

3 Tack a nail into the plank at the edge of each tad-nab, then wiggle the spiling board forward and remove it. Put a batten around all of the nails and draw a pencil line. This marks the inside face of the plank, seen from within the hull.

4 Return to the boat with a mini-bevel, pencil and a scrap of plywood. Work along the hull, taking the bevel between the frame and the edge of the plank below.

5 Mark each reading onto the plywood and label it with the station number. Mark this side of the plywood ‘lower edge’. Then, turn it over, mark ‘upper edge’, and repeat the process for the plank above.

6 Set the circular saw base to the maximum bevel for whichever edge you are going to cut and saw along the plank just outside the line. Do the same on the other side, and mark the end grain ‘forward’ and ‘aft’. Put the plank though the thicknesser to clean it up. Lay it inside-up on the bench, with the spiling board on top. Mark along the edge of each tad-nab and transfer the station marks.
Put the plank in the vices and work along, taking the edge down to each mark. Using the readings obtained earlier, reduce the plank edge to the correct bevel for each station. Then lay it on the bench, inside-up, and flop the spiling board on top. Feel along the edges to check they match. Work the hollow or curve into the plank, plane the caulking seams and shave a fraction off the inside edge with a block plane to remove the sharpness. Cut one end to fit, leave the other end a minimum of 3in (75mm) long.

7 If the plank needs to be steamed, steam it and then clamp to the plank above or below (choose the plank that has a little more twist than the shutter to be fitted). Unless you are supremely confident, this will save having to try and rush the shutter into place whilst it is still hot.

8 Once it has cooled, it can be fitted into place as normal. Start at one end and try to fit a clamp; failing that, wind in a couple of screws. Work along the plank with a good pad and a large hammer, driving it into place. This part is very satisfying – if the preparation has been done well.

As you come to the butt (or rabbet if the plank is full length), keep driving the plank home until it overlaps. Mark it up, then knock the plank back out for 6ft (1.8m) to give you space to work a saw, account for any bevel, and cut just outside the line. Clean up to the line with a block plane. Drive the plank back in and feel good. Make tea.

The post How to fashion a shutter plank appeared first on Classic Boat Magazine.

The plough plane is your hand tool passport to the cross-tongue joint, a key technique in the shipwright’s repertoire. The cross-tongue joins boards edge-to-edge, especially where the wood is thick and the tongue must be strong – in a transom, for example.

The tongue of an ordinary tongue-and-groove joint worked on the board itself has grain running the length of the board, but a cross-tongue has grain perpendicular to the boards and is stronger.

You could cut the grooves with a router or table saw, but the plough is easier, quicker and more enjoyable. Although an undamaged wooden plough is a rarity, there are many good alternatives in cast iron. Easiest to find is the delightfully ergonomic Record 043, which was made from the 1930s until the 1970s. This nickel-plated gem can be had for less than the cost of a biscuit jointer’s blade.

Begin by planing the boards flat and square, so edges meet along their lengths, and mark the face sides. A centreline scored on each edge will help centre the plough’s iron, which is chosen to cut a groove about one third the width of the edge. The gauge is set to cut just deeper than the groove is wide. The fence is held tight against the face side and locked to its arms.

A plough is used differently to other planes – you begin at the far end of the piece, working back to the near end, lengthening and deepening the groove with each pass, always keeping firm lateral pressure on the fence. Soon the plane is being guided by the tidy groove it has made, ejecting springy coils of shavings like so many nests of tagliatelle.

If grooves are slightly off-centre it doesn’t matter – the surfaces will match up as long as the face side remains your datum for the fence. Sometimes, boatbuilders would cut grooves deliberately off-centre so that maximum wear could be had from a surface before the tongue showed through.

Using a tenon saw, rip another board lengthways for the tongue, following lines spaced equal to the width of the groove. Then cross-cut to make pieces of the required depth, which should be just shy of the combined depths of the two grooves. The tongue is made up of several pieces arranged end-to-end.
An advantage of this joint is that you can use a different material for the tongue – a stronger timber, for example, plywood, or even Tufnol. Some 19th-century shipbuilders were using wrought iron!

Glue, assemble, and clamp the parts, and the joint is done. With this technique at your disposal, small stock need never be an obstacle to a big idea. A hatch, table or cockpit seat: no problem.

The post How to make a cross-tongue joint appeared first on Classic Boat Magazine.

Complete mini-series: From CB294, 295 and 296.

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Of all the brightwork on the deck of a good-looking yacht, the crowning glory is a Dorade skylight. It was only after fitting one that I also realised how very practical they are as well. Not only can much-needed light and fresh air pour in, it also acts as a wonderful vent for letting out foul air – or the smoke from the burnt bacon. I use a simple design, which doesn’t leak a drop, and is relatively easy to construct.

You’ll have to work out the dimensions of the aperture over which the skylight is to sit first of all. Typically, it will span three deck beams. It’s up to you if you want to chop out the middle beam where it crosses the hole. If you have concerns about the structural integrity of the deck or coachroof, get another opinion. You can always leave the beam intact, but in most cases removal shouldn’t be a problem.

Either way you’ll have to fit beams running fore and aft (carlins) to support the fore/aft sides of the skylight. While you’re cutting the hole in the deck, have someone down below watching your blade, ready to shout if you’re getting a bit carried away. Check that the rectangle you’ve cut out is true and measure its dimensions. You can now start making the four vertical sides of the skylight.

One common mistake is to build it too high. Just as a low coachroof looks sleek and elegant, the same is true of a skylight. I wouldn’t make the sides any taller than 3½in (9cm) for a boat up to 50ft (15.2m) in length.

Remember to add twice the finished thickness of your timber to the dimensions of the aperture to allow for the dovetail joints: so for a 35in (89cm) aperture, add 7⁄8in (22mm) twice to give 36¾in (93cm).

1: Cut the ends first. Don’t make the pitch too steep – a ratio of 5:2 works well. Put the ends back-to-back and make sure they are identical, with the apexes in the centre. For the sides that run fore and aft, you must also add a bit of height to allow for the pitch of the roof, whose angle is planed in later.

Now you can start on the dovetails. Before you throw CB overboard (“I knew it would get tricky”), take it from me: dovetails are not that difficult. If your joints are a bit messy, I can give you a couple of ‘get out of jail free’ cards later to help smarten them up.

Set a marking gauge to the thickness of your timber and score all round both ends of the four pieces. This gives the depth to cut the pins and the tails. Now mark out the pins. As there are three pins, the spacing is straightforward – the middle one is in the centre. Use a ratio 1:8, or 7°, for the angle of the wedge on the pins.

Be careful with the top pin. Remember you have to plane off the angle of the pitch, so make it fatter to compensate. Now put one piece in the vice and, with a tenon saw, cut along the edges of the pins, aligning the saw blade to the waste side of the cutting line. Do the same for all four ends.

2: When you’ve finished, lay one piece flat on a sturdy surface, clamp a deep, straight edge along the line from your marking gauge. This will keep your chisel square and straight as you chip away the waste.

3: Do the same for each of the four ends. It’s downhill from now on. Clean up the saw marks with a sharp chisel and you should have four pieces of timber looking something like this.

4: Mark the tails of the joint on the end pieces, using the pins you’ve already cut as a template. The thin part of the pins will be on the outside.

5: Cut the tails along the inside of the pencil line – again on the waste side.

6: Chip out the waste in exactly the same way as you cut the pins.

7: You may have a perfect fit first go. I never have, and rely on paring the pins until the joint slots together.

8: When all the joints are slotting together nicely, sand the inside faces of the boards with 120 grit. It’s much easier to do this now than when it’s been assembled.

9: Now you can glue it together. Use epoxy or polyurethane (not PVA – even the exterior stuff). Be sure to check that it’s square by measuring the diagonals.

Keep your clamps as close to the corners as possible, (not, however, over the pins), otherwise you can inadvertently bend the timber, which may set with the bend in once the glue has cured. Now is the time to use the ‘get out of jail free’ card to remedy a less-than-perfect joint.

Cut some thin wedges along the grain of an offcut of the same thickness timber. Clean up the squeezed-out glue and check for any gaps in the joint. Into these gaps you can carefully tap the wedge. Don’t worry if it doesn’t go in all the way – you can sand any protrusions flush once the glue has set hard.

For the really tiny gaps, you can gently tap the end grain of the pin with the ball of a ball-pein hammer. This will slightly splay the pin, but don’t overdo it or you will split the pin instead.

Next page: Fitting the centre beam of the skylight

The post How to build a skylight appeared first on Classic Boat Magazine.

In the shed with Will Stirling, the author is preparing ribs of green oak for the steam box by planing the merest sliver off the edges – what Will calls a ‘wire gauge’. When the 15ft mahogany clinker dinghy is finished (by spring), the two of them will sail it to the Scilly Isles and back. More in CB at a future date…

The post How to steam ribs on to a dinghy appeared first on Classic Boat Magazine.

A wooden fairlead is a work of sculpture in itself – tapered, moulded and shaped in every direction. It is a fitting as traditional as traditional can be; strong, simple and aesthetically additive to the boat as a whole. This small piece of wood sums up the challenge that wooden boatbuilding holds: functional aesthetics. The drawback is that for some it may be too traditional, in which case a bronze version serves equally well.

The aft end of the fairlead must be checked into the capping so that if load comes onto the fairlead it is not simply hanging on by its fastenings but is pushing against the timber of the capping, itself fastened to the gunwhale and butted against the transom… and so it goes on.

The sculling notch can be cut with a hole saw. For dinghies a hole saw with diameter of 2½ in (65mm)will do. Measure two-thirds the diameter of the hole saw down from the crown of the transom and centre the hole saw on the centreline of the transom.

In this way the hole saw will naturally create some return on the notch so that the sculling sweep will tend to be held in, and less inclined to jump out of the notch in the event of some vigorous sculling.

The sculling notch needs to be big enough for the sweep to have free play when sculling. Soften all of the edges with sandpaper.

1 Checking the aft end of the fairlead into the capping rail

2 The finished wooden fairleads varnished and ready for use

3 Sculling notch cut on centre line of the crown of transom

4 HMS Victory yawl fairleads

The post Cutting fairleads and sculling notches appeared first on Classic Boat Magazine.

When we cut out the window apertures in Sigfrid’s coachroof we used a jigsaw.

This worked very well along the top and bottom of the window, where the cut was straight, but was less satisfactory on the radiused corners.With a narrow blade the saw appeared to cope perfectly adequately with the curve but we found that it actually drifted out of square, resulting in a lot of work with the spokeshave to obtain a satisfactory result.

When we repeated this job in the front of the coachroof, we tried a different technique, which has been a lot more satisfactory. After marking the centres of the radii, each corner of the window was carefully drilled out using a suitably sized hole saw. As these holes were square to the face of the coachroof, it was now comparatively easy to cut out the straight sections, and the aperture required minimal truing up by hand.

The post Using a Jigsaw for Rounded Corners appeared first on Classic Boat Magazine.

While a wooden dinghy is the most fitting tender for any classic yacht, it can quickly become a complete nuisance while cruising.

Even on a large yacht, a dinghy takes up a lot of deck space when stowed on board. So as soon as the boat is anchored, it will usually be launched and tied astern. As long as the wind or current is strong enough to keep both vessels lying in the same direction, this is fine. Should the wind fall light or the current change, however, the dinghy will sooner or later end up alongside, tapping against the hull and threatening to damage the yacht’s topsides. Even an all-round rope fender does not solve the problem; all it takes is a large wash from a passing boat and the dinghy can easily knock the underneath of a rubbing strake with its gunwale, or get itself trapped under a counter stern.

In the 1970s, we moored the dinghies to the 50ft (15.2m) training ship Hardiesse using a boat boom. This system, which was simple and quick to rig, held the moored dinghy away from the ship’s side, avoiding damage.

The boom itself was a spar about 21Ú2in (62mm) in diameter and about 12ft (3.7m) long, which when rigged, projected horizontally from the boat’s side. It was located in a semicircular chock on the cap rail, while the inboard end fitted into a simple socket that was fastened to a stowage bin on deck. Dangling from the outboard end of the boom was a large block, through which ran a heavy ‘boat rope’. One end of this was tied off near the bow, and the other, just behind the block, was finished with an eye splice.

About 1in (25cm) from the eye, a small stick had been pushed between the strands of the rope. When the boom was not in use, this stick stopped the rope from pulling forwards out of the block, and kept the eye dangling from the aft side of the boom. If the boat rope was pulled tight, it was long enough to allow this eye to reach the ship’s side.The dinghy that was going to be moored to the boat boom was fitted with two painters. A normal one, about 13ft (4m) long and a short lazy painter that was only about 2ft (60cm).

When you approached Hardiesse, the dinghy would be brought up to the end of the boat boom, and the lazy painter tied with a sheetbend to the eye in the end of the boat rope. The dinghy was now walked in along the boom, until it was alongside the ship.

After the crew disembarked, the end of the painter was tied off near the inboard end of the boom. When the dinghy was released, it would lie to the lazy painter, safely away from the ship’s side. Retrieval of the dinghy was a simple matter of pulling on the painter to bring it alongside again, while if there was any chance of the wind falling light, attaching a stern line that led aft ensured that it could not tap against the hull.

The post Storing a Wooden Dinghy appeared first on Classic Boat Magazine.

Richard Hare unveils a novel way of dealing with teredo attack – fumigation.

Zanzibar is an archipelago of numerous islands, the largest being Unjuga, the island we commonly refer to as Zanzibar.

It’s also the home of the Zanzibar dhow, a vessel resonant of its Omani past.

Unpainted, rough-cut and with its yard  held together by hemp lashing, this plucky vessel still ply the African east coast with negligible freeboard, no ballast and seemingly no scope for reefing.

The way the locals keep teredo (shipworm) attack at bay is mind-blowing. Forget antifouling – they can’t afford it anyway – they take their boats out of the water once a month and smoke them. Most of the boats are fitted with drying-out legs and the tidal range ensures that they can be out of the water long enough between tides to get a good fug on.

Fires are lit along both sides of the hull.

To understand why hull smoking works we need to appreciate that although a teredo worm’s wood-gnawing head may be as much as half a metre – about 1ft 9in –  away from the smoke, buried inside the wood, its tail – a set of bi-valves, one for sucking in, the other for exhaling – is permanently cemented to the wood’s surface. This not only enables it to breathe, and be fumigated, but to procreate. If the tide serves it can even procreate itself, being a hermaphrodite.

The post Smoking a wooden hull appeared first on Classic Boat Magazine.

In the late 1980s, when I was working on a yacht restoration at Mylor Yacht Harbour in Cornwall, I learned a trick from local boatbuilder Brian Crockford. He was working on his own boat, Kelpie, a St Mawes One-Design, in the evenings after work.

He had a method of bending a piece of timber that did not require any special equipment: he simply used a household kettle, some absorbent cloths and a selection of cramps. I stayed behind one evening to watch Brian use this method to fit a new keel to his boat. The keel shape was straight until forward of the centreplate case, where it started to curve upwards towards the stem.

The garboard strakes had been removed, so the straight section of the keel could be cramped to the hog. The remainder, which needed to take up the curve, was then wrapped in the absorbent cloths, and soaked with boiling water from the kettle. After a few boiled kettles, he placed a couple of cramps a few inches ahead of the straight section of the keel, and tightened them enough to pull an almost imperceptible bend into it.

The rest of Brian’s evening was spent repeating the process. After several kettles of boiling water, the cramps could be tightened a fraction. Then a couple more cramps could be placed slightly further along, and slowly but surely the stiff and unyielding piece of timber would start to curve to the required shape.

I have since used this technique on several occasions. The main things to remember are to use plenty of cramps to spread the load, and to be patient. The timber will not suddenly become noticeably flexible, but it will eventually bend if the cramps are tightened little by little.

The post Bending Wood without Steam appeared first on Classic Boat Magazine.

Working alone presents unique problems. One occurred when I was replacing the beamshelves on my Polperro hooker Edith in Falmouth. After spiling off the correct shape of the 4in (100mm) wide beamshelves from 1.5in (30mm) thick larch, I needed to bend them into place.

Working with others, the larch could have been steamed until supple, then lifted and cramped into place mob-handed. I needed another way.

The solution was suggested to me by local boatbuilder Brian Crockford. His idea was to bend the timbers around the outside of the boat by cramping them to the sheer strake, then steaming them in situ. The bag was simply a closely-woven cotton tube large enough to slide over the beamshelf. One end was closed by lashing it around the timber; the other was lashed to a piece of plastic pipe fitted over the spout of a large kettle.

After an hour of steam from the boiling kettle, I was able to start bending the beamshelf. Working from the centre, the bag was slid off the timber, and the exposed section pulled in to the sheer strake. The secret is to work slowly, using plenty of cramps. Eventually, the beamshelf was cramped around the outside of the hull and the bag removed.

The following day the beamshelf was uncramped. Although it did spring back considerably, the timber held its shape sufficiently for it to be manhandled into place and cramped in its final position inside the boat.

The post Steaming a Wooden Boat Solo appeared first on Classic Boat Magazine.