Make your own silicone balls?
Ryan Tanner
Roger W. C. Hansen
<Ryan.W...@tek.com> wrote:
>Anybody tried to make silicone balls using silicone caulking?
>
>tan...@ethergate.com
>
>
the results in my case were somewhat less than satisfactory. I made a
plaster cast of a ball of the desired size, greased the inside and
filled it with caulk and pressed it together. The problem is the
chemistry of the caulk. Part of the curing process is exposure to
moisture in the air. There is no moisture in the plaster cast and
the curing is extremely slow. If you open them after only a few
days, the outer shell tears, and the inside is still gooey. The inside
will then start to cure with a bubble. I eventually left them in the
casts for a couple of months with the casts on top of a radiator to provide
gentle heating. This seemed to eventually cure them completely.
It is still very easy to get disturbing air bubbles in them. These
can be filled in a little and let dry. One then has to trim the material
at the mold line and fill hole. I never really found a good way
to do this except cutting them off with a scissor. I kind of lost interest
in persuing it further because the results lacked
the fine texture and bounce of the commercial product. IMHO this is
not a good way to make juggling props. I think the filler and other
additives added to the caulk change the product to much. I believe three
HiBounce balls cost about as much as the caulk and other materials needed
and work better.
charle...@my-dejanews.com
My father uses silicon rubber as a moulding material for casting pewter. He
has found in the past that to produce a really clear, clean mould one must
remove all the air bubbles from the mixture before it is allowed to cure; he
does this with a vacuum tank (not a particularly easy thing to build).
Oh, and the cured rubber smells *awful*. I used to take offcuts from moulds to
school to wind up my friends (I must have been about eight years old).
It's almost certainly easier to buy the things...
Charlie
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thomasl
manufacturers of silicone balls. ask todd smith or brian dube about it some
time...
write them a check as you do it. the silicone balls are worth it. they are
not a big money maker; it is almost more like a service providing them, cos
they are, as mentioned, a pain in the butt to make.
In article <75ljna$38o$1...@nnrp1.dejanews.com>,
M. Scott Dineen
Some years ago I made some cool silicone-coated street hockey balls. All
you do is cover a weighted street hockey ball (or other ball) with white
silicone from a tube (use a paintbrush). The texture, of course, isn't
smooth, but they have a nice grip and look decent.
I also tried for a smooth-skinned ball. I filled two halves of a 3.5"
Dube stage ball with silicone and stuck a stripped tennis ball inside.
When I pressed the two halves together (with the tennis ball inside)
most of the silicone was pressed out. When the thing dried (I checked
after two days) it had a smooth silicone surface that had just a few
bubbles in it and was practically spherical. The silicon skin felt and
looked good. I was sure a pro could do better, so I sent the ball to
Todd Smith, but I never heard back from him.
Ryan Tanner
with silicone and pressing it into two halves of a hollow
plastic ball. After a day or two, I'll remove the plastic halves
and see if the surface has firmed up enough. I tried making
half a ball as a test case, and only the open flat side cured.
I had no bubbles though. I think it will be easier to press out
air pockets with the silicone in the balloon before I put it in
the mould.
Anybody have ideas on how to make this process better?
M. Scott Dineen wrote in message <368027C3...@earthlink.net>...
tus...@my-dejanews.com
"Ryan Tanner" <tan...@ethergate.com> wrote:
> I'll have to try that. I'm thinking of filling a rubber balloon
> with silicone and pressing it into two halves of a hollow
> plastic ball. After a day or two, I'll remove the plastic halves
> and see if the surface has firmed up enough. I tried making
> half a ball as a test case, and only the open flat side cured.
> I had no bubbles though. I think it will be easier to press out
> air pockets with the silicone in the balloon before I put it in
> the mould.
>
> Anybody have ideas on how to make this process better?
Your problem is that you are using the wrong sort of material to make your
balls.
Use whats called an addition cure RTV silicone.
This comes in two parts like epoxy.
The smaller part B is added as a catalyst to cure the silicone.
After mixing, the silicone will set up after 2-24 hours.
(depending on what you use)
It doesn't need to be exposed to air to cure, so you wont experience
the problems you've been having.
If you have access to vaccum casting equipment, de-gas the silicone under
the vaccum dome before doing your pour. This will remove all the unsightly
air bubbles.
You can use the same rubber for the mold and the ball, but be sure to use a
release agent (like spray silicone) to keep the ball from sticking to the
mold.
I will warn you that the silicone will cost you over $100 a gallon.
And a low end vaccum table starts at $600.
Add in the difficulty inherent in casting a sphere... BTW this is really
difficult. You will ALWAYS have a sprue (little umbilical cord or rubber)
coming from a point on the ball where you fill the mold... and you have to
manage to fill your mold completely with no bubbles... whick takes skill to
pour and handle properly.
Unless it is the journey you are interested in, I might reccomend paying the
professionals to make your juggling balls. :)
Good Luck.
David Dalton
Morningwood Laboratories
Creators of the Manhood-Mold
(877)MOLD-YOU
Andrew Conway
tus...@my-dejanews.com says...
> [...]
> David Dalton
>
> Morningwood Laboratories
> Creators of the Manhood-Mold
> (877)MOLD-YOU
>
I hesitate to ask what the Manhood-Mold is, but I suspect it may be where
Mark Faje shops for props.
--
Andrew
Why do we bother bringing the canary down this goddam mine? All it does
is sleep.