7 August, '06

 

click to enlarge

click to enlarge

We sliced up the 2ft x 8 ft x 2in ( 600 x 2400 x 50 mm) blue polyurethane foam sheets on the table saw, cut just a couple of mm wider than the lead casting needed to be. Charlie has spent a couple of days up on the boat gluing a stack of these baulks together with Gorilla Glue. Note that this glue foams and swells the joint unless well weighted down so we had to carry in a stack of brick sized blocks of stone to weight it down.

It’s all bonded and rough shaped, impressive in its size, needing both surface finishing and the cutting of the bolt head countersinks.

While up there the power plane was taken to the leading edge of the keel to produce the streamlined shape required, interesting work using such an aggressive tool for fine shaping but it only needed a small amount of tidying up with the little Stanley block plane. Interestingly the Kwila, although very hard, works well with hand tools on a fresh cut area. I suspect that the kiln drying is slightly case hardening the surface making it difficult to work from scratch.

My purchase of an Arbourtech power wood carving tool has made the prospect of having to remove a lot of wood from the area around the propellor aperture a much less daunting prospect. There is a lot to carve out to fair the waterflow in that area, and the Arbourtech when fitted to my little 115mm Ryobi angle grinder made very short work of shaping up an offcut.

click to enlarge

click to enlarge

This tool is very different from the old Arbourtech which looked much like a set of chainsaw teeth welded to the circumference of a steel disc, it was one of the most dangerous woodworking things I’ve ever seen and remember that I’ve worked in sawmills a lot of my life! The second version was one that I have used in the past, and with its tungsten carbide teeth it worked well and was a little less of a menace.

This new one though is different again. It has a depth limiter built in, has only three teeth, and those are tiny cup shaped cutters (bell cutters) held in place with hex screws (allen screws). The disc is beautifully balanced; the cutters can be turned to a fresh edge when blunt and the whole package pretty much what you would expect from high quality tooling.

I have the special guard that Arbourtech makes, but it prevents the face of the disc from contacting the work and it’s this that I want to use to make long gentle passes to produce long fair curves rather than carve with the edge which most sculptors would want.

On trying the tool, it works great; very little kick or torque, it is easy to control (but is definitely not a one handed tool, and I have the second handle fitted) and removes material in a reasonably predictable manner. Note that even 40 grit commercial sandpaper just smokes on this hardwood, and hand planing the area is not an attractive idea. The Arbourtech carver seems ideal for roughing the area and we will be showing you the machine in action in next week’s diary.

John Welsford
Designer.