I have this tool which I think is from Grobet and I am using it
with the Foredom hammer handpiece. However I can't get it exactly
right, it is coming out dull ! Is there a trick to it , am I
doing something wrong ?
Change the angle of the stroke to the piece, and rotate the piece as
you work, so the various "facets" formed are at varying angles, to
catch the light. Also, move the tool around the surface fairly
quickly, filling in a whole area gradually, rather than totally
completeing one small section and moving on to the next. This will
give you a more random and uniform finish.
But, NOT doing any of this still should be bright. If you're
getting a dull finish, I'll bet the tool you've got has a chipped
culet on that diamond. Use a good loupe to inspect the point of your
tool. If the diamond is broken/chipped, you'll need to replace it.
Another possibility is that you've accidentally got a tool that's not
diamond, perhaps just a sharpened carbide or even steel tip. These are
often used, usually made by the jeweler, to create a non-sparkly
If your tool is diamond tipped, but needs replacing, you can use an
old melle, perhaps one with a chip on the girdle, so long as the
pavilion is clean still. It's a surprisingly standard bezel setting
job to get the diamond into the end of the steel tool, since the
steel holding the diamond is not hardened. The hardest part is
getting the broken stone out without too badly mangling the tool.
Sometimes you have to file off the old "bezel", and recut a new
seat. In doing this, make it a flat bottomed seat, such as with an
inverted cone bur. 46or this use, the table of the diamond should be
in good contact with the steel tool. the diamond is NOT just hed by