Classic Boat — January 2018

92 CLASSIC BOAT JANUARY 2018

CRAFTSMANSHIP

Boatbuilder’s Notes

Countersunk

nails

BY ROBIN GATES

If a copper boat nail is driven home

without first countersinking the clearance

hole it takes a lot of force to persuade

the head to lie flush. Wood fibres are

crushed below the head, and a crater of

bruised timber surrounds it. Viewed

obliquely, the nailed surface may

resemble the dimpled back of a

Chesterfield sofa. But if nail heads are left

standing proud they severely handicap

subsequent finishing – blunting sharp

edges and ripping up abrasive papers.

Given a couple of twists from a larger

drill bit to countersink the hole, the nail

head can be driven home without fuss,

and the flat plane of the surface is

maintained. If further finishing is

anticipated, knock the nail a tad deeper

with a tapered nail set, then the surface

may be planed, sanded or scraped

without damaging the tools.

Fastenings can be concealed if

clearance holes are also counter-bored,

then covered with putty or wooden

plugs, but the timber must be thick

enough or strength will be compromised.

Crook holdfast

The holdfast is an ancient clamp, with a beak bearing

down on the work and a shank passing through a hole in

the bench. It is usually made of iron, either in one piece

and hammered into position, or with an articulated beak

tightened by a screw, writes Robin Gates.

You can make effective timber holdfasts from grown

branches (CB338), but I’ve been bench-testing an easier

alternative – the crook handles of walking sticks. Typically

these are of coppiced sweet chestnut, with a heat-formed

curve, turning up cheaply in charity shops or from about

£5 new. Saw off the excess stick leaving 12in (30cm) from

apex of crook to tip of shank. Being about 1in (25mm)

diameter they work well in this size of hole; fine-tune to a

close-slipping fit with a spokeshave if necessary. Simply

strike the apex of the crook to lock the holdfast in place,

then strike the rear of the shank to release it. Small

wooden blocks between beak and timber avoid marking

the work. Besides convenience and economy, the

advantage of a wooden holdfast over iron is that it won’t

damage a sharp edge that runs into it accidentally.

ADVICE

1 Countersink the pilot hole with a larger drill bit 2 Use the hammer in line and

centred on the nail 3 Heads punched neatly below the surface by a nail set

4 The nailed surface is finished without obstruction

ROBIN GATES

ROBIN GATES

(^12)
4
Crook holdfasts and the
articulated iron type
3