Woodturning a Platter

2022-08-10
By Hornsby Mens Shed
Posted in Furniture/Cabinet Making, Woodturning

A suitable diameter for wooden platters generally is about 12-13 inches i.e. ~300 mm; but why choose 19 mm wood? This is the thinnest dressed wood that is practical, and readily available, for platter turning. Often this thickness is available in 300 mm (or greater) widths meaning that a 300 mm blank etc can be readily cut out on a band saw. Where lesser widths of suitable wood is only available good/strong lamination can be applied using similar or contrasting wood or woods to make-up the diameter to ~300 mm.

For this demonstration Queensland Kauri was used which had a pronounced but subtle grain. Using 19 mm wood the turner needs to be very cautious of the depth of cuts both on the face and the underside of the turning to ensure a final thickness of 5 mm minimum to look worthy of its design and to feel practical when handled or appraised, ie low density timbers will most likely be unsuitable. The demonstration’s turning techniques followed those given in the DVD. Care needs to be taken with accurate chucking as there is little, if any, spare wood to turn away to get correct squareness. An aluminium/hot melt glue chuck (face-ring) was used which did not protrude into the wood on the face side for turning the base. For the base chucking, a VM100 chuck with larger 100 mm circular expansion jaws was used. These jaws fit nicely by allowing the continuous circular footing to be 15 mm wide and slightly greater than one third of the diameter of the platter. The chuck recess needs to be between 3 to 4 mm deep, and for these jaws dovetailed at 77 degrees. Take care to get the dovetail precisely formed, square and with all chips removed from the depth of the recess.

To turn the base check for ‘squareness’ and adjust the aluminium face-ring in the jaws if necessary. From the centre measure a 100 mm diameter pencil line to accommodate the chuck; then measure and mark the 130 mm diameter for the outside of the platter’s foot. Between this 130 mm line and the ~300 mm diameter of the blank add lines to assist with profile turning of the underside, viz simple slope, Roman Ogee, or other, all of which need to fit with the later turning of the face of the platter. For this platter, because the thickness is restricted with an initial 19 mm, a simple underside was chosen with a somewhat thicker reinforcing ring between 130 and 180 mm diameter where the the face depth will approach its maximum. Note that the depth within the recess for the 100 mm chuck is convex and virtually nil at the centre to add thickness and strength to the turning.

A gentle curved underside from the 180 mm mark to the periphery is planned to give a ~5 mm thickness of the final piece. Plans for the platter’s ‘face’ is also to have a gentle but concave curve to achieve this 5 mm final thickness across its diameter. Rims, beads and deeper turning is virtually impossible as only about 14 mm maximum is available to remove on the top side of the platter i.e. 14 mm plus 5 mm for the base recess at its edges uses-up the whole thickness of the blank!

Care needs to be taken with the face curve which needs to be continuous, without any irregular
bumps or ridges and sanded to a very fine finish. Run through the grits to at least 400 followed by
brushing away all the dust in between, consider burnishing with wood chips and/or using 0000 Steel Wool, and finally using EEE and UBeaut Shellowax. The result should be a pale cream, thin and lite weight platter which because of its continuous slight curved surface shows its subtle straight grain to advantage. Another similar platter (turned previously from Australian Red Cedar) is shown which also exhibits pleasant grain together with a contrasting minor edge of its sapwood. This platter was finished similarly but with a final coat of UBeaut Glow which may show darker woods to better advantage. Another point of interest for ‘thin’ platters is the ability to cut and colour and even move the wood. Note how in the above platter apart from the colouring some wood has been carved away to form the tree trunks allowing the tree branch foliage to be moved across the platter and glued in a new position to produce a creative platter.