The properties that make a wood suitable for wooden clock construction are:
Medium to Hardwood
Retains detail when machined and sanded
Low distortion after machining
|Apple||Hard||Fine||Straight to Roey||2||1|
|Blackwood||Hard||Fine||Straight to Roey||1||2|
|Boxwood||V Hard||V Fine||Straight to Roey||2||2|
|Lignum Vitae||V Hard||Fine||Straight||1||2|
|Maple, Hard||V. Hard||Fine||Roey||3||2|
|Oak||Hard||Course||Straight to Roey||2||2|
|Walnut||Medium||Medium||Straight to Roey||2||1|
From this list I will make a choice, I will give consideration to what is available locally, how much its going to cost , and more importantly its suitability to for the different clock parts, as the frames and the gears and the arbors all have slightly different requirements, so will probably finish up with different woods for different parts.
To help with the choice I have made a few notes on each of the different woods.
It is heavy, brittle and has a fine, dense, even texture, and bends easily, and resists splitting. Well suited for carving and turning, as it’s extremely hard and limber.
European Alder has closed pores, and a fine, even grain. The grain is usually straight, but can also be wild or irregular depending on the growth form of each individual tree.
European Alder is very easy to work with both hand and machine tools; it sands especially easy. The wood is rather soft, however, and care must be taken to avoid denting it in some applications, not suitable for gears but could be used for the clock frames.
Ash is a long-fibered, light-coloured, medium-density wood, hard, heavy and with a course ring porous grain. It has a prominent grain that resembles oak, will split and splinter easily.
Beech is a heavy, pale-coloured, medium-to-hard wood used widely for chairs and stools. It has a fine, tight grain and large medulla rays, similar in appearance to maple or birch woods. Beech wood has a high shock resistance and takes stains well. Humidity adversely affects the wood.
The sapwood is generally creamy-white, and the heartwood is a very pale brown. It has an even and straight grain, and has good strength and bending properties. It is stiff, very hard, and holds a clean edge. Suitable for frames, keels, and deck houses. Sharp tools are required. Should be selected carefully and cut to avoid grain patterns. Warps readily if not thoroughly seasoned
Australian Blackwood has small, open pores and a fine to medium texture. Grain is usually straight to slightly interlocked, and sometimes wavy. Colour can be highly variable, but tends to be medium golden or reddish brown, similar to Mahogany. It is easily worked with both hand and machine tools, though figured wood and pieces with interlocked grain can cause tear-out. Australian Blackwood turns, glues, stains, and finishes well. Responds well to steam bending.
A very fine textured hardwood with a strong distinctive tanish cream to yellow colour. Very dense with almost no grain or figure. It carves with great detail. Used for turned parts and small detailed components. Boxwood is relatively hard to cut, even with extremely sharp tools, but the effort is worth the labour. A superior wood for clock parts, as it retains sharp edges and details to the smallest dimensions. Care should be taken as in time it can warp and twist if not supported.
Has a fine texture with close grain. The grain is usually straight and easy to work—with the exception of figured pieces with curly grain patterns. Cherry is known as being one of the best all-around woods for workability. It is stable, straight-grained, and machines and turns well. The only difficulties typically arise if the wood is being stained, as it can sometimes give blotchy results due to its fine, closed pores.
This is an extremely hard, dense wood with a close and very fine grain. A little hard to machine due to its toughness and hardness. Usually white to cream, but can be found in colours to pale yellow and pinkish-brown. Capable of an extremely smooth finish and can be turned to exacting dimensions. Doesn’t take stain well and is difficult to work, but can be carved to delicate detail. Hardness will dull and burn saw.. A substitute for boxwood.
Similar to pear, but slightly darker. Has a close, fine, and even texture, irregular grain, and bright satiny sheen.. Red gum can be used as a substitute in appearance for walnut.
Lignum Vitae has a fine texture and closed pores. Bare wood can be polished to a fine lustre due to its high natural oil content. The grain tends to be interlocked and tight. Lignum Vitae is regarded by most to be both the heaviest and hardest wood in the world. Its durability in submerged or ground-contact applications is also exceptional. Lignum Vitae has been used for propeller shaft bearings on ships, and its natural oils provide self-lubrication that gives the wood excellent wear resistance.
Unfortunately, Lignum Vitae has been exploited to the brink of extinction, and is now an endangered species.
Pale, almost white to pale creamy brown with a straight grain and fine uniform texture. Holds a fairly sharp edge, but frays when drilled and sawed. Bends relatively easy but has poor steam bending properties, and low strength. It finishes well but surface “fur” requires sealing.
This is a heavy fine grained white wood, stable, and among the hardest of usable clock building materials. Although excellent for small parts, its extreme hardness and occasional irregular grain make work difficult. Grain varies from a bird’s-eye figure to straight. Colour can be pale yellow to deep honey, and can be dull looking. Has high density, a fine, even texture, and is strong and stable. An alternative to box. Easily worked with hand and power tools. Holds an edge well and takes a good finish. Suitable for turnings, gears and it will ability to take a smooth finish, and show a distinctive sheen.
Soft maple, on the other hand, is relatively easy to work with. Because of their fine, straight grain, both varieties are more stable than many other woods. They also tend to be less expensive than other hardwoods
Oak is a hard, light to medium grey-brown, tough, short fibres wood with a distinctive grain structure. Like mahogany, because of its coarse grain structure is it not really all that suitable for model building.
Pear is a fine, close grained wood with distinct pores. Can be worked to delicate detail, bends well, and takes an excellent finish. Selected pieces have a straight grain. Turns and cuts well with a clean sharp edge, and holds sharp detail, but has a slight dulling effect on tools. An excellent wood for clock making, but a little scarce. Domestic pear has a cream to pinkish brown to rose colour and the grain structure is excellent for clock making. Foreign pear is usually of better quality, but difficult to find.
Grain is interlocked, producing an attractive mottle figure, as well as striped or roey patterns on quarter sawn surfaces. Texture is fine and even, with a very high natural lustre. Difficult to work on account of its high density and interlocked grain. Most surfacing and planing operations result in tear-out, especially on quarter-sawn surfaces. Pronounced blunting effect on cutters. Turns superbly. Glues and finishes well—able to take a high natural polish.
Walnut is a uniform dark purple brown. Even but coarse, open grain limits Clock making applications. Works easily, is hard, strong, and stiff. Free from warping or cracking. Sands to an excellent finish. Cuts and carves exceptionally well, but usually can’t obtain fine detail.
For Turning: Apple, box, cherry, dogwood, holly, pear, maple, satinwood…
I have not mentioned any sheet type materials here because I have a feeling that it would not be right to encourage anyone to spend so many hours building a complex mechanism like this only to have its aesthetic ruined by the use of plywood or MDF. These materials have their place, and if using a machine to cut the profiles then it could be beneficial to do a trial run using a sheet material.
Obtaining real wood in the right sizes can be difficult, but it should be encouraged because the finished result is so much better.
A possible source for wood blanks suitable for making the clocks is the suppliers of wooden flooring. They have strips of hardwood that can be fitted and glued together to form blanks in a wide variety of sizes and wood types.
The Hardwood Floor Store shown opposite is a typical example of this type of resource.