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6th July – Mike’s Mystery

8 July, 2015

“Mike’s mystery” is becoming a regular annual feature of our programme and can be relied on for entertainment value and technique tips.

Tonight’s demo started with a platter. With the blank mounted on a screw chuck, Mike faced up the bottom and cut a chucking dovetail. He immediately reversed this onto the chuck to turn the top. The reason for leaving the underside was to become clear later.

Mike's scraper

The top surface was faced up with a gouge and refined with a negative rake scraper which Mike uses a lot. I first saw this method demonstrated to good effect by Colwyn Way at Axminster. For those unfamiliar with the idea, the top surface of the scraper is ground so that it slopes down towards the edge. Unlike a normal scraper it is unnecessary to tilt it downwards since this is achieved by the rake on the top. This makes it far less critical to use and also allows it to get inside a deep box as it can be used horizontally. Mike claims never to have had a dig-in since using this grind which can be applied to any scraper. Incidentally, Mike uses a CDN grinding wheel and his grinder rotation is reversed so that the grinding surface moves away from the tool being sharpened. It certainly seems to give very nice tool edges.

 

Having got a nice flat surface Mike abraded and sealed it before applying texture. Mike prefers to use the more accurate term “abrade” rather than sand as most abrasives are not actually sandpaper. He uses a soft brush in between grits to remove particles which the previous courser grit may have left on the surface.

 

With the surface prepared he then used a Proxxon tool with a cutter to pass diagonally over the rim just twice to texture the surface. Mike likes the tool but questions why it has an on/off switch rather than a trigger that would allow it to stop once released. Colour (generally water based acrylic) can be applied to the surface and wiped off leaving the textured grooves coloured.

Mike's Proxxon

There is a large amount of hit and miss with texturing and colouring so if you don’t like the result you can re-turn the surface and have another go. Having left the platter thick, there is still plenty of material to enable this to be done.

The centre of the platter was then scooped out using a bowl gouge. Some people find it tricky to attack the wood at the right angle to avoid the tool skidding back (right across the finished rim!). The Keith Rowley “bible” suggests a way of coping with this by cutting a flight of steps with a parting tool using each step to support the bevel of the gouge at the start of the cut. Mike finished the surface of the bowl with a round nosed scraper ground with a negative rake before abrading it. The textured surface was brushed with a brass brush to remove the rough edges left by the texturing cutter and the whole thing sealed by spraying with sanding sealer.

Mike's bowl, showing rim

During the tea break Mike set the lathe up on the stand with the bed and turning centre vertical! The purpose of this was to spin blobs of diluted paint placed in the bowl. Results are unpredictable but can be interesting and attractive. We had a bit of audience participation and several of us stepped up to have a go. For most of us, if we are going to give this a try at home, we’ll have to invent other means of spinning in a horizontal plane as it would be a challenge to tip our lathes up on end.

 Mike, lathe on end  Mike and Lynda

Once you think you have something worth finishing the platter needs to be reversed again to turn the underside.

Mike's examples

To round off the evening Alan Sturgess gave a critique of the members gallery, which once again disappointed in the number of items brought in though some were very impressive. All the pictures as usual are on the website.

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