I have a Tormek T7 water cooled sharpening machine. There is a black silicon wheel available which will lightly sharpen tungsten carbide tools. Has any one used one for sharpening TIG tungstens? If so what were the results? The stones are large, 250mm dia and very expensive, circa £130, but as I do not have a bench grinder at present it can be offset against the cost of getting one, whilst retaining the benefits of no grinding dust.