This time we will craft a circular board. Maybe you already had to face the problem that when sawing a circle it will become more sort of oval shaped instead. And if by any chance a circle will be sawn it has jags and shoulders. Whether you will mould the circle with the help of a band saw or a circle cutting devise and the router, the surface itself will never be nicely sanded, unless you are working with a CNC machine or a fixed mill with circle cutting devise.

Our tip will help you crafting an exactly round table top for example needed for a coffee table.

Theoretical assembling
Graphics: Theoretical assembling

By using a cylinder bolt (1) mount the base plate (3) to the base (2). This way the base plate (3) will remain partially flexible. The table top (4) which has been roughly cut and provided with a covered drilled hole, will – also by using a cylindrical pin (5) – be fixed onto the flexible side of the base plate (3). Now rotate the edge of table top (4) alongside the sanding block (6) until the base plate (3) rests steadily against the stop bar (7).

Step-by-step explanation:
  1. The table top

    The plate has a diameter of 500 mm, so the thickness ought to be 19 mm (for the plate of our coffee table).

    Roughly mould, saw, cut the table top, which means in this case just under the mark drawn with the compass.

    If you do not have a jigsaw or any other machines, you can use a frame saw and narrow jigging blade alternatively. We also offer compass and compass heads.

  2. The base and base plate

    The base (multiplex, chipboard or MDF) is the basis for the circle sanding jig.

    Besides a base plate (multiplex, chipboard or MDF) is needed on the base as a sliding arm.

    The base and base plate
  3. The sanding block

    We now need a sanding block. It can be made out of chipboard, e.g. a 38 mm chipboard or massive wood. Glue sand paper onto the large side of the block. Apply glue to the block and clamp it for about 30 minutes, using an extension (you can also use spray-on-glue or adhesive sand paper).

    You may choose a coarse block for the rough grinding and a fine sand paper for the finish grinding. When exchanging the block during work, you should mark the position of the block in order to not change the diameter, e.g. two blocks with exactly the same dimensions and bolt holes.

    The width of the block should be chosen so you can turn it once the sanding paper is no longer sharp enough. This way you can make use of the entire sheet of sanding paper.

    The sanding block
  4. The stop bar

    Finally a stop bar is needed, also made out of chipboard or massive wood. It has to be thinner than the base plate. E.g. a plate of 16 mm if the base plate is made out of 19 mm chipboard.

    The stop bar
  5. The function:

    The base plate has to be connected to the base with a smooth dowel or cylindrical pin. Then fix the sanding block.

    Now adjust the necessary diameter with the stop bar. Measure the distance from the centre of the bolt to the sanding block. This distance has to comply with the radius of the necessary circle. The stop bar will be screwed on the left angle of the base plate.

    The function
  6. Sanding the table top

    The table top will be applied to the bolt and turned until the base plate rests against the stop bar.

    The bolt can be made out of a dowel or a cylindrical pin, this will ensure even more accuracy. Just drill a stud hole into centre of the table top. In our online shop you will find suitable drills, e.g. wood twist drills made out of carbon steel.

    Plug the dowel into the stud hole and cut it flush with a flush-cutting saw. Then you can veneer, paint or varnish the plate.

    If you wish to grind a plate which has already been veneered you may use the hole of the dowel as accent. A piece of solid wood used as an inlay is a real eye-catcher. We also do offer exquisite kind of woods.

    Sanding the table top