Version 1.05 March 2020
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6.2.9
TRANSFERRING
Read the section on the Transfer Fixture which explains how the dops
are set into the fixture. In setting the dops into the fixture, see that the
key (chamfer) on the dops are firm against the edge of the pushers",
aligning the dops radially.
Set the new cavity dop into a V-block of the Transfer Fixture. Select a
cavity dop which covers about 2/3 of the pavilion. Tighten the clamp on
that dop. Into the opposing V-block, set the initial dop. Tighten the clamps so that it allows the initial dop to
slide when pushed on by the "pusher".
Be sure the surface of the cavity dop is clean, and apply a drop of adhesive (or less than a drop--not too much)
to the holding surface. Slide the initial dop--pushing it with the "pusher" to maintain its radial position--so that
the pavilion is pressed firmly into the cavity dop, and lock the position by tightening the clamp on the initial dop,
with the stone under some pressure into the cavity dop. With a toothpick (or whatever) put a small fillet of
cement around the stone where it exits the cavity dop. Set the Transfer Fixture on end, the old dop side down--
and wait. This is a good time to get a cup of coffee, or tea -- 10 minutes will probably be sufficient for the
adhesive to set up, but longer is better.
When you remove the stone, do it carefully--loosen the clamps and get them out of the way-- you now have
cavity dop-stone-flat dop, and the original flat dop has to be removed. It's a complicated-sounding instruction,
but it's easy: you need an alcohol lamp, a small damp cloth, and small pliers. Light the alcohol lamp. Hold the
stone with the damp cloth (to keep the stone cool when heat is later applied), with the cavity dop resting in your
palm (avoiding a stress between the stone and the cavity dop), and hold the old dop in the flame. As the dop
warms, hold the stone firmly in your fingers (with the damp cloth), and use the pliers to apply a side pressure to
the heated dop--and at some point the dop will separate from the stone--it sort of pops off. (In this process,
don't make the mistake of removing the wrong dop(!)--a message from the Voice of Experience).
You are ready to facet the Crown. Insert the dopped stone into the Spindle and lock the position.
6.2.10 CONFIRMING ALIGNMENT WITH THE PAVILION FACETS
The Crown Facets are usually cut to align with the Pavilion facets--the keying arrangement will provide a
reasonable alignment, but some adjustment may be needed. Use the Index Vernier.
To check the alignment, place a 1200 lap on the platen, set the index position of a
facet, set the angle at about 85
and with the lap turning slowly, slide the stone across
the lap. If the resulting mark is parallel to the edge of the girdle on the pavilion side,
you have verified the alignment. If some amount of out-of-parallel is observed, make a
correction by rotating the Index Vernier. Having completed the alignment, you are
ready to proceed with faceting the crown.
6.2.11
FORMING THE CROWN
– BREAK FACETS
...
Proceed in a way similar to the faceting of the Pavilion, use the coarse lap only for removal of much
material
—finish setting the facet with the medium (graduated to a pre-polish) lap.
Proceed cautiously and inspect often.
Break Facets
–set the Angle Dial at 52
˚
96 Index at: 3, 9, 15, 21...etc…steps of 6…to 93
Cut the break Facets so that they meet at points along the
girdle
—
leave a thin polished girdle of 2 or 3% (this is a guess--don't
worry
about it--your judgment in this will improve with time)-
remember, it was polished previously.
