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Bakelite?


#1

I often here about the term Bakelite with vintage jewelry. Does
anyone know of any simple tests that can be done to distinguish
Bakelite from just plain old plastic or celluloid? One person said
that they do a simichrome test but would not elaborate. Anyone out
there that could share some tips or know of a good book to refer to
on the subject?

Thanks in advance,
Gisela


#2

G’day Gisela:

    I often hear about the term Bakelite with vintage jewelry. 
Does anyone know of any simple tests that can be done to
distinguish Bakelite from just plain old plastic or celluloid?  

Try the famous hot needle test. Heat a needle to just redness; I
always have several of different sizes shoved eye first into pieces
of 8mm wood dowel - they’re handy for all sorts of things. Touch the
hot needle to a part of the object that is unobtrusive, and smell the
vapour that arises. A smell of phenol comes from Baekelite and is
quite unmistakable. Celluloid gives a smell of camphor. But you’ll
have to further specify ‘plain old plastic’, for there are a very
large number of materials which come under the heading of ‘plastic’,
from vulcanised rubber to polythene to polyvinyl chloride (PVC) to
cellulose acetate, to ethyl cellulose, to nylon, to polycarbonate
to… and so on. Each plastic gives off it’s own special smell
with the hot needle test. Thus, educate your nose! – Cheers for
now,

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#3

Gisela, I use 409 to test for Bakelite. Just put a little on a q-tip
and rub a small area of the piece. You will see a yellowish stain on
the q-tip if it’s Bakelite. I’ve read that you can also use Scrubbing
Bubbles in the same way, but it can destroy the finish so you have to
be careful. (I haven’t tried it.) I have used simichrome to
clean/polish old Bakelite, and it also creates a yellowish stain.
There are some exceptions. Check out Karima Parry’s “Bakelite
Bangles” book, there is a chapter on testing, plus other good info on
Bakelite and other plastics.

Good luck,
Sharon


#4

Tests for plastics can be found in Webster’s “Gems.”

Scrpae a few chips from the base of the clean material - where it
won’t be seen.

Put them in a test tube and cover with distilled water.

Boil the water.

Ad a small amount of dibromoquinonechlorimide.

Cool it.

Add a drop, by drop a very very dilute solution of sodium hydroxide.

If the color turnms blue then the presence of phenol is indicated -
thus the material is very probably Bakelite.

Tony Konrath


#5

The best and safest way to test and identify vintage plastics is
with simichrome polish which you can purchase at most hardware
stores. It’s somewhat expensive, but it is also great for polishing
bakelite, silver, and most any metal. Polished bakelite will leave a
yellow residue on the cloth regardless of what color the bakelite is.
Another good way to test for bakelite is to hold it under hot water
for about 30 seconds and then smell it. Bakelite has a very distinct
odor somewhat like a shellac. Hope this helps, Marilyn Bachtel
Flash Fire Trading Co.


#6

You can test for Bakelite by rubbing it very briskly on your
clothing for a few seconds until it builds up some heat with the
friction. Then smell it. It has a very distinctive sort-of-petroleum
smell. If you have something you know is Bakelite, try it until you
learn the smell. If you don’t have anything, then many antique stores
have bakelite costume jewelry you can do the test on. (There’s lots
of stuff being sold as Bakelite that isn’t, however!)

Rene Roberts


#7

Hello, Gisela - As a collector of bakelite bangles, this is one of my
favorite topics. Originally Leo Baekeland’s (hence, bakelite)
thermosetting phenolic formaldehyde resin, ‘bakelite’ quickly became
a somewhat generic term for any phenolic resin. Trade names include
Catalin, Prystal (a little later in time and translucent), and
Marblette. Once the resin has been heated and formed, it cannot be
remelted - which is why it was used extensively for things like
kitchen pot handles and parts for electric items. And of course it’s
quite decorative, so it was also used extensively for just about
anything else you can think of.

One of the commonly heard of tests is the red hot pin test - DO NOT
DO THIS!!! This will greatly reduce the value of an item, in
addition to being unsightly, and possibly dangerous if you are wrong
about the material (celluloid could potentially burst into flame).

The currently accepted tests aRe:

  1. Examine the piece: Bakelite is heavy. Bracelets make a lovely
    clunking noise when worn together. There is a characteristic look,
    feel, and sound to bakelite which is understood with a little
    practice.

  2. Smell: If it will not damage a piece, dip it into hot water.
    There is usually a characteristic nasty smell. If it smells of
    camphor it is celluloid.

  3. Chemical: Use the tip of a q-tip to lightly swab a bit of
    Formula 409 in a discreet area - bakelite usually will rub off a
    yellow residue. Wash the piece immediately afterwords to remove any
    remaining chemical residue.

  4. Think!: Sometimes a European phenolic resin will not exhibit much
    of a smell. The yellow residue from the chemical test is due to the
    patina that bakelite develops with time - if an overly enthusiastic
    person has recently scrubbed and polished an item, it may no longer
    have a patina, and hence no residue. Sometimes, you really just have
    to go on instinct and educated practice.

Also, be aware that there are new resins which are duplicating many
of the characteristics of bakelite. The Taiwanese resin tends to be
too heavy, and does not have the correct smell in hot water. There
was also a lot of leftover bakelite from various factories which is
now being made into new jewelry. Some of this is appropriately
collectible in its own right as there are a few modern artisans doing
excellent work with this vintage material.

As far as books and websites, you can’t go wrong with
fantasticplastic.com. Her book about bangles, which you can buy on
the site, is excellent. Rhinestoneairplane.com is also an excellent
purveyor of vintage and new artisan bakelite.

Enjoy!
~kara