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Hollow spheres


#1

I am making hollow spheres that look more like silver blobs than
spheres. They measure between 8 and 15 mm in diameter and are
between 15 and 12 gauge thick. My previous attempt at making
these are as follows:

  1. Cover head of dapping punch with purple carving wax and heat
    wax with small torch flame at the same time as you turn the
    punch, to insure an even thickness of wax, dripping hot-as-hell
    wax on fingers causing skin thereof to peel.

  2. Lick burnt fingers.

  3. Cast, mold. There’s one half of your thick half-dome, in wax,
    which I imbed metal objects into and cast, then solder to
    another half dome thereby creating a “sphere”.

  4. Lick burnt fingers.

The problem is that once this is finished the sphere is not
round enough for my taste. Is there a way to take an imperfectly
shaped metal sphere, with sprue attached or removed, and lathe it
(or use another process) into a sphere? It doesn’t have to be
perfect- just close.

Any suggestions greatly appreciated.

Peter Slone


#2

Hi, Peter. Applying wax to the head of a dapping punch should
give you a perfect inner surface, which unfortunately will not be
visible on the finished bead. If you use a depression in a
dapping block to shape your wax, that should give you a
relatively smooth and symmetrical outer surface.

Lee


#3

Peter, Why are you not dapping the spheres. That will certainly
make them round and give a consistant metal thickness. If you
must cast the halves then why do you not dapp the cast halves
after you have cut off the sprues? If you are concerned with the
texture of the metal surface you could dap into a wooden block.

Good luck,
Etienne Perret
www.etienneperret.com


#4
    I am making hollow spheres ... The problem is that once
this is finished the sphere is not round enough for my taste. 

One person I heard of covered round candies in wax; when the wax
was hardened, they drilled as little hole and melted the candy
out. Took some time to soak the sugar all out, but she got
perfectly round spheres. Maybe this would work for you? Easier
than lathing!


#5

Cut out a round disk, dapp into a 2/3 sphere and repeat, file
each half and solder together, better yet order them, or at
least order some heavy walled beads possibly available with a
single hole that you can plug, I’m sorry about your fingers,
happens to mine ever since I started at the bench at fourteen,
its just a part of the job that sucks, but eventually you will
develop these thick sexy calluses and things hurt less, in
theory. Alicia Arnold


#6

Peter,

Perhaps one of the lapidary sphere grinding machines might be of
some use? I’ve never seen them used for that purpose, and there
might be some little problems, or adjustments to adapt the
machine to that purpose, but it may be worth a try? If you have
a local lapidary club, I am sure that someone can direct to a
member or a “friend of a friend” that could help you out. If the
walls are thick enough - it just might work…

Brian P. Marshall


#7

peter slone - thank you for a good laugh on a very bad day! your
post reminded me to do more work on my in-progress book: ‘the
dangers, pitfalls, hazards & other fun aspects of the
auto-instructed/empirical method of jewelry design &
fabrication’ - with foreword by marquise de sade. chapter 1
title: ‘soldering: preview of hell’, subtitle: ‘never even think
about trying to stop a rolling ball of molten silver solder
hell-bent for the edge of the worktable’. (in that chapter i
also plan to outline just how to murder a partner who thinks
it’s funny to goose me while soldering.) chapter 2: ‘putting a
positive spin on pieces wheel-launched into space during the
polishing stage’, subtitle: ‘the law of averages will allow you
to find previously lost pieces while looking for the currently
lost item & the crawling exercise is good for you.’ peter,
awaiting more posts from you when your fingers heal. ive


#8

Peter, I would attepmt to fabricate the spheres from sheet since
it sounds like you have the appropriate dapping tools. Start
with a circle that is cut out to be 1/3 larger than your
finished spheres dia. For example… for a one inch dia.
sphere, make two 1.5 inch circles and start hammering them into
domes with a dapping tool a little smaller than the concave
surface of your dapping block. Try not to strike the center of
the circles because they will become too thin. Work it around
in the dapping block moving from the 1.5 inch opening to smaller
and smaller openings untill you reach the 1 inch (or whatever
size you’re making). I solder the halfs together in a little
divit in a fire brick and all of mine have came out round as
marbles. I learned this from a very informative post here a while
back. You might try searching the archives if the above is
confusing.

good luck,

Jeff Cleveland aka JevFro
505 E. 3rd
Ellensburg, Washington 98926
JevFro@hotmail.com
http://www.cwu.edu./~clevelaj


#9

Hello Peter, Would it not be easier to put a silver disc in a
dapping block and stike it with a dapping punch until it is half
a sphere? you could make two of them and then solder them
together. This would give you a perfect sphere. Good luck. Tom
Arnold


#10

Peter, hollow spheres are best made with a dap and punch
technique. Once you get the technique down, you can mass-produce
them to cut down on time: drill holes in the discs first, dap all
the discs, solder together, then polish them all. I use a hard
wood forming block and make punches from hardwood dowel rod. This
forms and stetches the metal without compression and mechanical
marring. If you have a hole through one side to the other,
string the completed beads on a stiff wire with a little free
space. You can then hold them to a bench polisher, they turn
themselves and no burned fingers. If you really want to cast
them, what about that new water dissolve wax? You make your form
with this wax, overlay it, and then dissolve the inside form with
warm water. Haven’t tried it, but it sounds neat. Maybe someone
else on the list has some experience with it. Good luck.


#11
 If you must cast the halves then why do you not dapp the cast
halves after you have cut off the sprues? 

There are metal objects imbedded into the wax domes that
protrude beyond the surface ( used to support the object in the
investment when the wax has been burned out ) of the dome which
will be sanded off after casting the domes. It seems that a
combination of all the steps ( from the initial model to the
mold to the wax to the imbedding to the casting to the finishing
), but especially the filing off of the protrusion of the object,
adds up to the overall degradation of the finished product (not
to mention my lack of skill).

Also, at the point of insertion of the metal object, there must
be atleast a 2 mm thickness of the dome, plus another layer above
the object inside the dome to facilitate complete fillingof the
casting- hence the need for a thicker than usual dome.

                Thanks for your help,  Peter Slone

#12

Peter,

Don’t know if this has been mentioned but why not use a soft wax
in the dopping block to get your wax spheres. I use a little
dishsoap so the wax doesn’t stick.

John