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Casting Fingerprints


#1

A customer of mine would like to have the thumbprints of his two
small children cast in gold. Would anyone be able to suggest a
good way to obtain a sharp wax of the prints suitable for
casting? Any suggestions would be greatly appreciated. Thank you
in advance, Michael Chapman Tallahassee Florida, USA


#2

Micheal, You may try using prcious metal clay and bake it. or
you can have the children use elmers white glue making a thick
layer them apply wax to the surface the glue should peel of in
one piece. or have them press their fingers in semi cool candle
wax. good luck… Ej


#3

Hi Michael,

The only way that I can think of reproducing fingerprints in a
casting is to photo etch them. A cheap and easy way would be to
get a good black and white copy of the fingerprints. Take them to
an engraver who makes magnesium photo etchings for printers. Ask
them to photo etch your images into thin magnesium stock. A
couple of things to specify are that you want to be sure that
the lines of the fingerprint are recessed (they would normally do
it the other way for printers), and that the stock they use is
only 1mm thick (they would normally use much thicker). Once you
get the plate back you can cut it to whatever shape you want and
mold it. Than shoot a wax and cast it. The photo etchings will
cost about $15.00 each. Thats the best I can do.

Good luck,
Mark P.
WI


#4

Jennifer + Michael, here’s one idea. take a flat peace of soft
sheet wax and have the kids put there thumb prints in it. then
cut the shape you want and cast it.


#5

Don’t know if it would be applicable, but a friend had a similar
problem several years ago when a customer wanted a sketch done in
gold. He had an individual who does glass etching copy it in
glass and made a wax from the etched glass. I know it worked but
no other details. Have Fun Ash


#6

I use bees wax that has some charcoal mixed in it. Have the
customer roll the wax between fingers and when wax is soft and
is in a ball set down on a piece of wax paper, press thumb in and
vola. If the wax sticks you can rub a small a mount of oil on
thumb. Set up as any other casting. But when mixing investment
thin it out some.

No snow or ice up north
True


#7

A neat idea! Casting the kiddies’ fingerprints!

Are they old enough to sit still for 5 minutes? To make
open-face molds I use a dental material (Skip? What’s an
American name?) Mix the two parts together and slather it on the
finger. Sets up (remains flexible) and peels off in a few
minutes. Then pour molten wax into the mold; release the wax
when set; cast. It’s a quick process and gives excellent
detail…

Colleen
New Brunswick


#8

Since the children probably wouldn’t appreciate sticking their
thumbs is hot wax and it would stick badly, the solution becomes
one of using a mold material that isn’t hot and wont stick to the
thumb. I would suggest a thick mixture of investment. You could
then flow a layer of wax over the inprint, add a sprue _hole, set
the mold in a casting container and will with investment and cast
it. Regards
Joe


#9

Since my mail feed was interrupted this morning, I don’t know if
you got an answer to this question yet, but it occurs to me that
the solution might be to etch the thumbprints in, instead.

Not having done any etching in gold (I last did etching for
print making about 10 years ago), I can’t give you any more
detail, but a quick perusal of the Orchid archives should give
you any other details you’d need, should you decide to etch
rather than cast.

Kat Tanaka
@Katherine_Tanaka


#10

Hi Micheal, Just a thought, but I have had good luck with latex
rubber… You can paint on a thin layer on the fingertip, let it
dry and peel it right off. You would have to have an impression
of the same finger in, say clay or plaster, to have the rubber
maintain the shape as it won’t support any weight on it’s own.
Then, just a low temp hard wax painted over the interior rubber
to desired thickness and there you have it. A little trial and
error will be necessary, but it should make an exact copy.

Good luck,

Terry Swift


#11

Hi Michael!

I did just this a couple years back. If’n I recall rightly, I
made two tiny sort of picture-frame charms out of green wax.
Rectangular with smooth edges and rims, and a textured
background. Then I rolled out beeswax with a thin wooden dowel a
cut ovals that would fit within the frame. When ready, we had the
customer bring in the kids and set their prints on the beeswax
which I’d laid into the frames.

From that point, just be careful to get it to the caster intact
and be sure your caster is forwarned -DON’T TOUCH THE BEESWAX!!
Once cast, polish the frame only, texture any background that
shows and just lightly brass wheel the print itself.

Good luck!

Jane


#12

Hello Michael:

Try dental molding material, the same stuff they use to make
impressions for crowns, bridgework, ect. It’s non-toxic,
inexpensive and makes an excellent impression. Simply mix this
2-part material when your customer and their children arrive with
clean hands, have the little ones impress their desired diget(s)
in the material. After allowing to set for just a few seconds
while the stuff firms up, remove the fingers and there you have
it. a negetive impression into which to pour melted wax. This
will give you a perfect impression to carve into whatever your
customer wants(charm, earrings or ring) and cast away. Hope this
helps;

Steve Klepinger
Bench jeweler, caster, model maker and old car nut.


#13

Colleen, The material you mention is called Dental Alginate here
in the US. :slight_smile: -Pete-


#14

Michael, if you don’t have access to an engraver for the
magnesium plates, you can also take the fingerprints with an
inkpad and scan them into a computer to generate a high-contrast
image for etching with PnP paper. Or, you might even have luck
Xeroxing the prints straight onto the PnP. Then take your mold
from the etched plate.

Rene


#15

I did this some years ago. I used the lid of one of those little
square plastic stone display boxes for a frame. Melted some wax
with a low melting point into it and pressed my wetted thumb.
Worked perfectly. I also made a handprint knife handle with
injection wax in about the same way. After dipping the knife
tang into my wax pot over and over I simply gripped the handle
with my wetted hand. Wax doesn’t stick well to a wet hand. Try
it yourself before you getthe kids to do it.

Bruce D. Holmgrain
Maryland’s first JA Certified Senior Bench Jeweler
@Bruce_Holmgrain


703-593-4652


#16

Hi Micheal,

   Just a thought, but I have had good luck with latex rubber..
You can paint on a thin layer on the fingertip, let it dry and
peel it right off. 

Terry’s idea is a good one, but build up 2 or 3 extra layers of
the latex and then apply a layer of thick plaster too support the
latex. The latex dries rather quickly between layers with the
aid of a hair dryer, and the plaster sets up fairly hard in a
matter of minutes. Also, Texas Art Supply has a mold compound
that lets you get a 3-D mold of a person’s finger, hand, etc. for
making candles, so I think that this could also be used. It
probably sets up very fast and is flexible enough that there
would be no difficulty getting little fingers out. You might
want to check out art supply stores in your area.

Lynn BellCrystal Legends
http://www.wtrt.net/~lynnb

@lynnb


#17

If you have not solved your problem try this.

Printers use a photo polymer plate material to make printing
plates from, these plates use a UV source(black light) to set off
the photo polymer.

  1. Your need to get the child’s finger print image on a piece of
    paper, the image needs to be clean and sharp).

  2. Scan the image on photo shop and clean up the details.

  3. Save and print the image on a transparency sheet as a
    reversal (a negative of the actual print). These steps can be done
    by anyone that knows photo shop and has a printer that will do
    transparencies.

At this point you should have a transparency of the child’s
finger print as a negative image.

Rio grand has a system called “Model Master” (expensive) you
can buy the polymer sheets from them. I like the yellow,
aluminum-backed plates. Call and Rio Grande for a catalog (it’s
on page 37).

With the transparency and the photo polymer plates you can
expose the plate and have a plate with the child’s finger print.

This plate can be used to make a rubber mold.

Using the rubber mold you can then inject a wax.

This process is simple and if you take one step at a time you
should have a great image to cast.

good luck

if you need more info respond back!


#18

Fingerprint update

Well I finished the fingerprints today and just wanted to thank
you all for all of your responses and to let you know what I
ended up doing. Simple, just melted some white candle wax into
the bottom of a cut off soda can, vanilla I think, let it cool
down a little and let the children push their thumbs into the
soft wax. After it cooled down just flash the bottom of the can
with the torch and the whole thing comes right out. The wax is
still soft so you can turn the depression up so it curves like a
real thumb. Cast just like normal. This also fits the magnetic
tumbler thread because that’s where they went after the sprew was
cut off and the back smoothed off. Gave a very nice finish
without removing the detail. Put on a bale on and engraved their
name and birthday on the back. Thanks again for your help,
Michael Chapman