Demonstration

Review: Rob Till Demo – Sunday 17th March, 2024

Rob’s demonstration focussed on turning green wood. There were three parts to the demonstration: rough turning a bowl, a bird house turned from a log, and a vase.

Preparing Green Timber for Storage

Rob gave a few tips on preparing green timber for turning.

  • Seal the ends of logs with PVA glue and newspaper. The newspaper helps prevent the log from splitting.
  • For short term storage, partly turned green wood can be wrapped in clingfilm to stop the wood from drying out. This is particularly useful when taking a short break from the lathe. This is also OK for a few days or even a few weeks but not for longer because mould will grow.
  • For longer drying periods, partly turned items can be stored in shavings in a plastic bag or a box.
  • Write the date and weight on the wood. Weigh the piece regularly to see how much drying has occurred and update the date and weight on the wood. Use a moisture meter. Less than 10% is considered dry.
  • Always protect your lathe with oil before turning green wood. Oil the lathe again after turning and clean your tools.

Rough Turning a Bowl

Rob started with a part turned lime bowl mounted on worm screw and supported by a tail centre.

Create a dovetailed tenon with a flat shoulder for the jaws to rest against. Undercut the tenon. Shape the outside of the bowl using a pull cut. Next mount the piece in a chuck. Don’t crush the tenon by over tightening which is easily done with green wood. Again support the piece with a cone centre in the tailstock. Flatten the face using a bowl gouge. Start the hollowing using bowl gouge. The aim is to get an even thickness to allow even drying. Rob turned the bowl to approximately 1” thick.

Weigh the bowl and write the weight and date on the bowl. Seal the outside and edge with PVA glue but leave the inside unsealed to allow moisture to escape. Store in a cool place. You can also can put the bowl in a bag or box of shavings.

Rob will post on the club FaceBook page to show how the blank progresses over the next few months.

Green Turned Birdhouse

For the bird house, Rob use an ash log from a tree that had been felled about three months earlier.

Note that, according to the RSPB, bird houses should have a drain hole at the bottom, be at least 12 cm deep, have no perch (to prevent attacks from woodpeckers) and have an appropriate hole size for the nesting birds (see the RSPB website for details).

A 25 mm entry hole is best suited for smaller birds, such as blue tit, coal tit and marsh tit. A 32 mm entry hole (protected with a metal plate) is suitable for slightly larger garden birds like great tit, tree our house sparrow, nuthatch and lesser spotted woodpecker.

The log is mounted between centres, Rob used Steb centres. Make sure the log turns free of the tool rest before switching on the lathe. The log is rounded. It might be prudent to do the roughing with a bowl gouge, rather than a roughing gouge, if the log has visible knots. Rob swapped to a spindle roughing gouge once the log had been smoothed by the bowl gouge.

Create a dovetailed tenon on one end. Since the log is long make sure the tenon has the maximum depth for the jaws to ensure that the log is safely mounted for the hollowing process. Mount in the chuck and support with the tailstock. Shape using a roughing gouge. Flatten the face. The tailstock end will be the top of the box.

Drill a deep hole to help the hollowing. Normally Rob would drill a hole using a ½” Morse taper drill or a drill in a Jacob’s chuck. The lathe only just coped with the drilling because Rob was using an exert adapter.

After drilling you can store the roughed blank wrapped up if you wish.

Next Rob started to hollow the box using a WoodCut Hollowing Tool. It hollows out quite quickly. Use a round skew to create a straight recess about 10mm deep (to fit your jaws for later mounting) and a ledge for the roof. The wall thickness needs to be decided at this point: 3mm is OK. Even thickness helps prevent splitting. Rob checked the thickness and straightness using callipers.

Rob also showed us the WoodCut flexicut. Then Rob demonstrated the Hope 6mm Hollower, a more affordable option than the WoodCut. The 6mm tip is turned to 45 degrees.

Before removing the piece from the chuck, mark the jaw locations for remounting. If you are going to leave the piece for any length of time, then wrap it in cling film and fill with shavings. It should be OK for a few weeks, but not longer. Rob then mounted a piece he had previously hollowed.

Reduce the waste material at the base end and start to shape. Take care to measure the wall thickness and depth to avoid cutting all the way through! Rob then reversed the piece in the lathe, held by the chuck jaws in expansion and supported by the tailstock. As mentioned before, the opening recess of the bird house matched the jaw diameter. Adjust the piece to get it nicely balanced on the lathe.

Now create the final shape of the bird house base. Note that fine finials do not work with green wood, so just do something decorative.

The lid is made from a slightly larger diameter log held between a Steb dead centre and a tail cone centre. The face is flattened using a bowl gouge.

Create a dovetailed tenon. Mount in the chuck. Smooth the face. Rob tried to keep some of the live edge as a decorative rim of the roof. Make a tenon to fit the box opening and undercut the area around the tenon by a few millimetres deep to allow the lid to fit over the box rim.

Next start to shape the lid but leave some bulk near to the chuck as we still need to hollow the lid. Create a recess to fit your jaws in expansion mode.

Hollow the lid using a spindle gouge. Then use the Hope Hollower with the swan neck tip to undercut the inside of the lid. Shape as much of the lid as possible.

Rob then reversed the lid and mounted it in expanded jaws. The final shape is turned. Wrap the box with the lid fitted to allow slow drying (if you leave the lid off you might not get it back on!).

RSPB advice on positioning bird boxes:

Nest boxes for tits, sparrows or starlings should be fixed two to four metres up a tree or a wall. Unless there are trees or buildings which shade the box during the day, face the box between north and east, thus avoiding strong sunlight and the wettest winds. Make sure that the birds have a clear flight path to the nest without any clutter directly in front of the entrance. Tilt the box forward slightly so that any driving rain will hit the roof and bounce clear.

Green Turned Vase

For the vase, Rob used a log which he thought was cherry. The log is mounted between a Steb dead centre and a tail cone centre. Turn a dovetailed tenon and then mount the log in a chuck. Start to shape the neck and create the opening. It is nice to keep a natural edge on the rim but Rob wasn’t that lucky, it came off.

Because Rob was using an exert adapter, there was a lot of vibration, so Rob decided to shorten the log and start again.

Form the shape of the neck and opening and determine the wall thickness. Next gradually form the outer shape of the vase neck. Once you are happy with the shape, hollow out the neck to the desired thickness.

Next hollow out some of the body of the vase. Then refine the outer shape. Continue to hollow and refine until you have reached the desired depth. It was necessary to drill a hole to ease the hollowing. (Note the drilling of the centre could have been done at the start.)

To help get a thin wall Rob inserted an led light: the light should shine evenly through the wood when the thickness is even. However, the light didn’t really shine through as Rob had hoped it would.

Refine the final shape. Sand inside and outside. Then shape the foot. Rob added a bead feature. Sand again.

Part off the vase. Add a spot of superglue over the base to stop splitting.