Restoration technique

Attractive, hand-cut joints are more or less a prerequisite of quality furniture. This is largely to do with aesthetics, but at the same time, there’s an appreciation for the ingenuity of joints like the secret mitered dovetail. Precise joints can secure a piece of furniture with only the additional use of glue, and even the early, relatively crude, mortise and tenons needed just twin wooden pegs to strengthen them.

The emphasis on traditional joint-making in fine furniture means that many people consider the use of metal fixings to be a modern and almost sacrilegious phenomenon. But such a romantic notion ignores the fact that they’ve been used quite legitimately in fine furniture for centuries, and in surprisingly large quantities, while ordinary mass-produced furniture since the middle of the nineteenth century has widely used metal fixings. So next time you’re using the Concept KTX screws, just remember that they’re merely the latest in a long and honourable tradition!

History nailed Handmade iron nails have been used since the earliest plank chests, where they were needed for the hinges and locks. The wood and metal in such pieces will have aged together to frequently create something greater than the sum of the parts. In later pieces, the pine backs of fine cabinets were often crudely fixed with iron nails, which regularly split the carcase timber, while smaller nails were used to secure drawer bottoms before the development of the modern runner. As a result, deep grooves worn into cabinets by nail heads are common in surviving pieces, and oxidisation grinning through the finish of the highest quality furniture of the period is witness to the nails and pins holding the mouldings.

Screws have a shorter history than nails, but have come to be seen as more load-bearing. They first appeared in brass with hand-cut threads in the second half of the seventeenth century. As they were very expensive, their use was limited to the top end of the market, and they were still used in conjunction with nails for securing hinges of long-case clock doors well into the eighteenth century. Then came a bit of technological progress: brass and iron screws could be cut on a lathe rather than by fi ling. Although they became more plentiful, the cost didn’t fall dramatically until the appearance of standardised machine-made screws in the mid-nineteenth century.

If the use of screws in the so-called Golden Age of English Furniture, however, was commonplace, it was also discrete. The only difference now, then, is their visibility and acceptability as a design feature in their own right, just like those original medieval iron nails.

Handling metal fixings For the restorer, all of this means that nails, pins and screws are as much an integral part of furniture as the wood and the original finish. It also means that they should be accorded as much thought before you start your project. In practice, this presents three specific challenges.

Firstly, do the fixings or the wood hold priority if something has to be sacrificed? If the screws securing the corner blocks of a nineteenth century chair are locked solid and likely to sheer, what do you do if you need to dismantle the chair to affect some other repair? Do you drill the screws out and save the braces or chop the braces away and (possibly) save the screws? All restoration implies some form of risk and my instinct is to minimise potential damage and loss, so in this case, I would sacrifice the screws, provided the braces were sound. But were the braces riddled with woodworm and crumbling away, I would sacrifice them and keep the screws for re-use. The second challenge is what you use to replace the screws and nails if they’re sacrificed or missing. You may think it rather sad to collect and recycle old nails and screws; I’ve managed to build up quite a collection, but if you like to get out more, my advice is to use the nearest modern equivalent. When it comes to size, err on the side of the screw being smaller, as an over-large head can stand too proud. New heads can be disguised with a dab of an appropriate earth pigment suspended in shellac if necessary. I always pre-drill for even the smallest pin to avoid splitting.

As a basic principle, I always aim to use the original method of fixing. For example, in the eighteenth century, the protective cockbeading around drawers was secured either by animal glue, pins, the two together or, very occasionally, by wooden pegs. But if, say, no pins were used in the original, I wouldn’t use any for the restoration, even though it’s easier and quicker than making tiny oak pegs, which are fiddly and relatively time-consuming. There are, however, two provisos for keeping the status quo: the original fixing should be in the right place and it should do the job intended, or else you’re justified in making alterations. On occasion, I have re-aligned or moved a fixing and even substituted a screw for a nail, and vice versa, when the original was clearly ineffective. Never automatically assume that the original was right — woodworkers have always made mistakes.

Thirdly, wood shrinks, and you may need to re-position screw holes. This is particularly important when re-assembling round or oval Victorian tables – the centre joint often springs because the top is secured rigidly with up to a dozen screws through the sub-frame. Unless the screw holes in the underside of the top are re-positioned, the same stresses will be set up and the joint will spring again.

Road to ruin Obviously, just whacking a nail or forcing a screw in where none was originally envisaged or needed has no place in restoration. A screw down through the seat of a Windsor chair is no way to repair a loose leg and drawer sides secured with large-headed nails will soon come adrift again. These are not clever short cuts, and they often cause more harm than good without solving the problem. Ultimately, short cuts stem from sheer laziness, and are examples of ‘bodged’ jobs. Which, handily, is the subject of next month’s article!