One
of the questions I have heard over and over in my years of workign
with polymer clay is “how long should I bake this” This question
gets tossed out periodically and everyone seems to have an opinion.
Mostly there seems to be two main schools of thought among the clay
artists. Those that bake for a long time to make sure their object is
cured (I know of a few that bake all their items for an entire hour)
and those that bake for just a few minutes. If you have watched me
make clay foods you know I am one of the short bakers. We all have
our reasons and I think most of us stand by those reasons, we all
want to be correct. However, is there an absolute correct?
I
decided to approach this question just like I tell my kids to
approach questions when they come to them. I've been homeschooling my
kids since the oldest was in 2nd grade- he just turned 30.
For the most part I have homeschooled for all those years. All but
the youngest has attended at least a year of public school at some
point or another. The youngest by the way is 14 in case you were
wondering. Anyway, when the kids come to a question of this sort I
tell them to do an experiment and show the answer.
So
now I had a plan, do an experiment but what kind of experiment should
I do? How should I set it up?
My
first step was to gather up a package of each brand of clay I have- I
stuck to pale colors since I figured that would show us if the colors
shifted from the long baking process. I then decided to add in the
translucent version of each brand also since in most items I make I
use a mix containing translucent clay and I know it reacts
differently to heat than the other colors.
The
brands/colors I am using:
Sculpey
III- tan
translucent
Fimo-
Pearl
translucent
Premo-
Ecru
translucent
Cernit-
White (Number 1)
translucent
Next
I checked what the manufacturers had to say about both baking time
and temperature. They varied a bit from Fimo translucent calling for
230 degrees Farenheit to the remainder calling for either 265 degrees
or 275 degrees.
Premo
called for baking for 30 minutes per ¼”, Sculpey for 15 minutes
per 1/4”, Fimo for 30 minutes with no thickness mentioned and
Cernit for 15 to 30 minutes again not mentioning a thickness.
I
made a few decisions about temperature since I wanted to bake all the
straight clays in one batch and all the translucent mixed clays in
another single batch I decided to go with the lower temperatures
stated for each batch. So I baked the translucent mixed clays all at
230 degrees and all the straight colored clays at 265 degrees.
Next
I labeled 2 sets of 5 plates with the following times, 5 minutes, 10
minutes, 15 minutes, 30 minutes and 60 minutes.
I
used my pasta machine to make sure I had consistent thickness to all
the clay pieces. I rolled all the clays on first the thickest setting
and cut out the 5 discs recquired for the test then rolled the rest
of each clay to a middle setting and cut out 5 more. I labeled all
the discs so that I could be sure of which were which brand. For
labeling I simply used a letter stamp to press a letter in the top of
each disc (F for Fimo, C for Cernit, etc)
I
then baked the plates at the assigned temperature for the time stated
on each plate.
After
all the plates of clay were baked and cooled I proceeded to check the
clay discs. First a visual check of the color of each disc. Was is
the consistent between the different baking times.
Next
I checked to see how hard/soft each disc was, and at the same time
checked to see if they had become brittle.
I
think the most surprising aspect of this test is that even though the
clay discs had cooled for a couple of hours none of them were really
hard. I think leather like is the best description. I have now let
them all sit overnight and they are still the same way. Not a single
one has hardened up like I expected.
Since
the Sculpey III was the one to give the most trouble I am extra glad
that I very seldom use it. I have never really liked the way it works
up nor do I particularly like the colors of that brand of clay. For
the most part I find the colors to be rather harsh compared to Fimo
and Premo. I do use Sculpey III when it is the only brand that offers
a color I really need, like their Sweet Potato color. I also tend to
pull out the Sculpey III when I want to mix with TLS to make
frosting, the softer texture does mix much more easily than the more
firm clays I normally work with.
Will
I change my cooking method, yes, I will probably lean a bit closer to
10 cooking time for things that I want to make more stable. I still
will use the shorter times though, I see no reason to cook for longer
than I need to and in some cases, since it did cause a color change
it would be a real problem.
I
may at some point run the translucent mix clay test again leaving out
the Fimo and bake at the higher temperature called for on the other
brands just to see if the results are the same or change.
So
did you learn anything from this test? What would you like to see as
a clay test later on? Be sure to let me know what things you would
like to see tested in future videos.
Now
lets look at those pictures I took of the baked clays: