How do I make a solid wood table top?

A table top is the most demanding panel most people make: it is wide, it is seen from every angle, it must be flat, and it lives in a heated room where the humidity swings a long way. Almost every problem it can develop is decided before the glue comes out.

What you'll need

• Boards of sufficient total width, thicker than the finished dimension
• Sash clamps, several
• A jointer plane or router setup for the edges
• Cauls and a flat surface
• Movement fixings for the base

Step by step

1. Buy the timber early and let it acclimatise.Sticker the boards in the room the table will live in for at least a fortnight, with air to all faces. This is the single highest-value thing you can do and it costs only time.
2. Buy thicker than you need.Flattening a wide panel costs several millimetres. Starting at the finished thickness leaves you with a thin top or an unflattenable one.
3. Arrange the boards and mark them with a triangle.Grain and colour flow first on a table top, because it is a show surface seen from above at close range. Photograph the layout.
4. Joint the mating edges straight and square.Test dry with no clamps and no light showing along the joint. A joint that needs clamping to close is a joint under permanent stress.
5. Glue up in sub-panels of two or three boards.Two narrow panels are far easier to keep flat and to flatten than one wide one, and they fit through machines and vices that the whole top will not. Joint the sub-panels together as a second glue-up.
6. Use cauls at each end of every glue-up.Battens above and below across the panel, waxed or taped, keep the joint faces level. Alternate the sash clamps above and below the panel.
7. Leave each glue-up a day before levelling.The wood next to each glue line is swollen with water from the glue. Level it now and each joint sinks into a groove as it dries.
8. Flatten the top by reading it first.Winding sticks for twist, a long straightedge for cup and bow. Take the twist out first, then the cup, then smooth along the grain.
9. Decide the edge treatment.A crisp arris slightly broken with a plane, a chamfer, a bullnose or a moulded edge. Whatever you choose, do it after flattening and take it right round consistently.
10. Finish both faces equally.Same finish, same number of coats, underside included. Unequal finishing is a leading cause of a top cupping.
11. Fix it to the base with sliding fixings.Buttons in a groove, figure-of-eight plates, Z-clips or slotted holes, with the slots running across the width. Rigid fixings will split the top.

Tips

• If flattening a large panel by hand is beyond your tools, many small joinery shops will run a top through a wide belt sander for a modest fee. Ring with the dimensions before you glue up, so you make it a size they can take.
• Breadboard ends look right on a farmhouse-style top and genuinely help keep it flat, but they are an advanced joint and have to be fitted so the panel can still move.
• Aim for the grain to run the length of the table. The width is where the movement happens, and the base fixings are what allow for it.

Common mistakes

• Working timber straight from a cold merchant's yard — It has a much higher moisture content than a heated house, and it will shrink after you have glued and flattened it — opening joints and cupping the top.
• Gluing all the boards in one operation — The open time runs out, the panel is unmanageable, and any twist is locked in across the full width. Sub-panels make every stage controllable.
• Screwing the top down solid — A wide solid top can move several millimetres across its width across the year. Restrained, it splits.

Questions people ask