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3rd September – Dennis Keeling

10 September, 2012

Dennis has been turning since he was 10 but it took a back seat whilst he earned his living in engineering. He took it up again in 1977 as a hobby and developed an interest in making bowls from wood segments. This became his passion after a course in New Mexico with Bud Latven opened his eyes to the creative possibilities and the techniques which make them possible.

Whilst segmented turning has a much bigger following in USA than in UK, the origins were arguably in England in the 19th century, e.g. in the form of Tunbridge ware. Similar developments occurred about the same time in Italy and Scotland.

Dennis has become a well-known and respected turner of segmented work and is a director of the Segmented Turners Association. He sells his work internationally, does demonstrations and tuition. Tonight we were treated to a masterclass in the art of segmented turning.

I wondered how he was going to squeeze the hours that go into the preparation into a 2 hour demo. He achieved this by clever use of clips from his video showing the preparation and assembly leaving time to demonstrate the final turning process on the night.

Anyone seriously interested in having a go themselves should get the video or his book as I’m not even going to try to give a verbatim account.

The actual turning usually represents no more than 20% of the effort, the rest being in the design, making the segments and building up the assembly. The secret is to draw up the design and do the maths to determine the size and angles of the segments. Dennis uses a computer programme to help with this but the maths isn’t particularly difficult (he says!) The segments must be made accurately to avoid gaps and the risk of coming apart. This is a laborious process though investment in modern precision machines for planing, thicknessing (preferably separate) and mitring minimises the need for hand finishing.

Dennis uses Titebond glue to join segments in each ring, painting on each end grain face. This forms a strong joint very quickly by just pressing together. Clamping is best avoided as the stresses created can lead to failure in the final piece, often much later. The rings so formed have their lower faces flattened by sanding for assembly one at a time on the lathe. The starting point is a solid base which Dennis glues to a scrap piece of mdf held in a chuck via a paper sheet. This enables the assembly to be broken free at a later stage. Each ring is added and glued in place with pva. This is preferred to Titebond for this operation as the joint is not end grain plus pva is invisible. However, each ring needs to be pressed in place on the lathe using a disc on the tailstock and left to dry. The face of the top ring is then turned flat ready for the next one.

Once thoroughly dry the assembly is ready for turning. The inside is turned first. The reason is that once the inside is finished the bowl can be supported from both ends to turn the outside to a thin wall thickness. A gouge is not suitable for turning the inside because of the reach and the glue which blunts it. Dennis starts using a hollowing tool and finishes with a tungsten tip tool (available from Simon Hope).

  

The assembly is then removed, the scrap base broken off and reversed onto a stepped cone and supported by the tailstock. A gouge can be used for the outside. Once the general shape is established, Dennis presents the wing of the gouge to the surface so as to sheer scrape.

The method used for the attractive open segmented designs is very similar but a jig is necessary to assemble each ring as the segments don’t touch each other. Dennis uses a commercial jig called Seg-easy (?). Each ring of segments is glued and pressed to the lower one whilst still in the jig. The jig is removed when the glue is dry and the ring faced up ready for the next ring.

Turning is the same except more care is needed particularly at the bottom because the contact surface area is much smaller. Dennis uses a tear drop shaped sheer scraper to finish the inside. One advantage of the open design is that when turning the outside, the thickness can be seen without taking off the lathe. Examples of Dennis’s work that he brought to the demo are pictured below.

   

Some members had apparently anticipated Dennis doing the gallery critique and the table held a number of impressive segmented items. All the gallery items can be seen on the website.

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