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Information for
First-time Users of Best Mix Mold Mix
Best Mix Mold Mix is a
powdered compound with a consistency similar to cement so, in handling
and disposal, treat it as if it were cement. Use facemasks, latex or
rubber gloves and closed frame safety glasses when handling since
excessive exposure to the dry power form of Best Mix Mold Mix can cause
respiratory discomfort, dry skin and eye irritation. Clean up with
water but do not to dispose of the waste through household drains!
For best results,
store and use Best Mix in heated spaces, especially during the mixing,
pouring and curing periods. The ideal working temperature is 70 degrees
F.
The Best Mix Mold Mix
powder may settle and compact during shipping. We highly recommend that
you loosen and redistribute the contents of the shipping box by pouring
all of the mix into a second, larger airtight container such as a 5
gallon plastic bucket with a lid. Then, before each use, stir the Best
Mix Mold Mix powder; an even distribution of particle size will ensure
the best mold possible.
Working with Master
Molds
To cast fused glass
slumping molds from Best Mix, you first must have a master mold. We use
the term master mold to refer to the pattern or scale model that you
plan to use for slumping your fused glass. Basically, it’s the shape
that you want to replicate in your glass. Master molds used with Best
Mix have to be watertight and waterproof. The process of hardening Best
Mix Mold Mix is a chemical reaction that requires the presence of water.
This process takes 12 to 24 hours to achieve maximum strength, depending
on the size of the mold. If the proper amount of water is maintained
during the hardening and curing process, you will have a strong mold; if
you lose water because of a leaky master mold, you may have a crumbly
mold.
The best choice for
nonporous master molds is plastic or glass, however, any material that
can be waterproofed can be used. Wood shapes, for example, can be coated
and sealed with lacquer, polyurethane or varnish. Whatever shape you use
is then placed on a nonporous surface, with a dam or rim around the
outside edge to contain the Best Mix. The edges of the shape must be
sealed with hot glue or polymer (oil-based) clay so the water doesn’t
seep underneath.
Remember, the surface
finish of the master mold will be exactly duplicated in the newly cast
slumping mold – what you see and feel now will be imprinted in your
future slumped glass. Make sure your master mold surface has the
smoothness or texture you want in your finished glass piece.
Estimating Volume
of Best Mix Needed
An accurate amount of
mix should be determined prior to the mixing stage – you don't want to
come up short once pouring starts. Use dry, clean sand to fill the mold
to the proper level, then pour out the sand and measure the weight or
volume. The measured amount of sand is a good estimate of the amount of
mold powder to use.
Using Mold Release
The use of a mold
release is essential to the parting of the master mold and the cast
mold. We have found that vegetable oil spray (non-soluble in water), and
particularly olive oil spray, makes an excellent mold release. A light
coat of the spray is recommended -- and make sure that the coating does
not puddle in low spots – then use a clean paper towel to spread an even
shine of oil on all surfaces before pouring. The use of two release
agents is the standard practice of professionals that cast in other
mediums. There are waxes, dry silicone sprays and many other agents that
are used professionally. We recommend that you test several release
products on simple projects before taking on that really big challenge.
Mixing to the Proper Consistency
We use currently use
two techniques for mixing Best Mix. We call them the Pouring Method and
the Layering Method.
The pouring method
mixes Best Mix to a consistency similar to cement. When you pick up a
hand full of Best Mix it might drip through your fingers a little and if
you shake your hand it will definitely begin oozing through your
fingers.
The layering method
uses a much thicker form of Best Mix Mold Mix. We use this method when
the master mold is a shape that would make for a very large, awkward or
heavy slumping mold with the creation of a dam around it. When using
this method, the consistency of the Best Mix should be such that it
forms a ball that does not come apart when you pick up a handful of it.
If you shake it in your hand, it will very slowly try to flatten.
Whichever method you
use, we recommend using water temperature for your comfort. In warmer
climates cool water is just fine as is warmer water in colder climates.
Just remember, the warmer the water at the time of mixing, the faster
the setup. If you use hot water, the mix might harden faster than you
can get it poured!
Mixing for the Pouring Method
For pouring method,
measure Best Mix Mold Mix and clean tap water by either weight or volume
using these ratios:
By Weight: 4
units powder to one unit water
By Volume: 3
units powder to one unit water
After initially
wetting the powder, continue to add the measured amount of water and
stir to a consistency of thick concrete. The recommended ratios for Best
Mix Mold Mix and water are not absolute, so add the water slowly. If the
mixture seems too wet, add a little more dry mix. The mixture should be
just wet enough to move through the mold when vibrated or patted.
Mixing for the Layering Method
After initially wetting the powder,
continue to add small amounts of water and stir. Best Mix Mold Mix needs
to be dry enough to be able to toss a ball of it in the air and not have
it come apart. The recommended ratios for Best Mix Mold Mix and water
are not absolute, so add the water slowly. If the mixture seems too wet,
add a little more dry mix. The mixture should be just wet enough to move
when patted with your hand.
The Mixing Process for Both Pouring and
Layering Methods
Whichever consistency
of Best Mix Mold Mix you need, thoroughly mix for five minutes. Don't
skimp time on this step. Yes, it will look mixed after a minute – but
for complete hydration of the powder, it takes active agitation for at
least five minutes. Don't cut the time short.
Cover your prepared
master mold all at one time. Use of the dry sand method of estimating
mold volume described previously will ensure the proper amount without
waste.
After pouring, you
have about 20 minutes of working time to finish the process before
letting the mold setup.
Trapped air bubbles
need to be moved off the slumping surface of the mold so it is smooth.
Shaking or tapping the master mold lightly on a countertop or floor will
help move the bubbles off the slumping surface (no need to be concerned
about how the back of the mold, the non-slumping surface, looks, which
is where many of the bubbles will end up). No more than 2 minutes of
vibration should be necessary; also stop agitation if the mix starts to
harden. This process levels the mix and produces the finished surface on
the bottom of the slumping mold; there is no need to use a trowel.
Shaking the mold isn’t
recommended when using the layering method, since the mix will slide
down the sides of the casting. Instead, press out the bubbles as you pat
the surface while layering the mix.
Before the mix hardens
is the time to make vent holes -- creating them now will be much easier
than trying to drilling them in later. Finishing nails work good. (For
those unfamiliar with the term venting – during slumping air may be
trapped and sealed between the glass and the mold resulting in an
incomplete slump or the formation of large bubbles in the glass.
Providing small air vents at the lowest parts of the mold
eliminates the problem.)
Next, place the poured
mold on a level surface and cover with plastic. The mold must be
kept covered to retain all moisture for the entire setup time of 12 to
24 hours (depending on thickness).
Removing the plastic
cover and pull the casting apart from the master. If the casting doesn’t
release with light tapping and pulling, try heating the casting on top
of a warm kiln. Set the Best Mix side of the casting onto the lid of a
600 to 800 degree heated kiln. The heat expands the water in the mold
ever so slightly, which helps to part the master and the casting. Be
patient. With proper mold preparation and enough applied heat, the
finished mold should come out of the master mold.
Your finished mold
needs to be fired to full fusing temperature. We do this to ensure
complete drying and burning out all organic materials. Good ventilation
is needed here. Allowing the mold to dry out on it’s own for a day will
reduce the amount of moisture being released into your kiln.
|
Mold Curing
Schedule |
|
Degrees/Hr |
To |
Hold |
|
|
40 |
225 |
2 Hrs |
Drives out
moisture |
|
55 |
400 |
1 Hr |
Ensures a dry
casting |
|
75 |
1400 |
1 Min |
Final heating
and burnout |
|
Off |
|
None |
Cooling |
Notes
Best Mix Mold Mix
produces molds primarily for fused glass slumping. Slumping molds that
we have cast and tested to date show no sign of failure after hundreds
of firings of up to 1280 degrees F. (At this time, there is no known
limit to the number of repeat firings.) Also, we have discovered that
the use of kiln wash may not be needed when slumping with molds made
with Best Mix Mold Mix. In 100 percent of all test firings, using both
Uroboros and Bullseye fusing glass, glass has not stuck to the molds
when fired at slumping temperatures up to 1280 degrees. We occasionally
have seen small specks of the mold surface pull away, but never a
complete failure to release. We regularly use a fine layer of dry
kiln wash on the surface of the mold to make sure the glass does not
stick. However, when we have a deep mold where the glass has to slide
down the slumping surface, we do a normal wet kiln wash. This decreases
the possibility that the glass will catch during the slide.
Since we have no
control over how Best Mix Mold Mix is used, we cannot make any guarantee
as to your success with this product and will not be responsible for any
losses connected in any way with the product’s use. We will
gladly help troubleshoot any mishaps or answer any of your questions via
e-mail or phone.
We are dedicated to
the success of Best Mix Mold Mix and that can be accomplished only by
your success in making the best molds possible from it. Feedback is
welcomed and encouraged – we want to know about your experiences using
Best Mix Mold Mix.
We will share our
experiences and working techniques using Best Mix Mold Mix as we find
time to document our results. We encourage our customers to also share
their experiences and thoughts. E-mail us at
info@bestmixproducts.com and we’ll publish your results.
Best Mix Mold Mix
Instructions for Use
Determine the volume
of mix you will need to fill your mold.
Measure Best Mix Mold
Mix and water into separate containers.
By Weight: 4
units powder to one unit water.
By Volume: 3
units powder to one unit water.
Prepare master mold by
cleaning it and using mold release.
Add water depending on
the type of mold you are making:
Pouring
method:
Add
water slowly to mix until the consistency of loose cement.
Layering
method:
Add
water slowly to mix until it can be tossed gently in the air and not
fall apart.
Mix for five minutes.
Fill master mold until
all surfaces are covered.
Shake or tap mold to
remove air bubbles off the surface of the master.
Fill master the rest
of the way full and shake or tap lightly again.
Place a nail in
shallow area(s) of mold for a vent hole.
Cover mold with
plastic.
Let sit for 12 to 24
hours, depending on size of mold.
Separate master and
casting.
Clean up casting with
putty knife.
Cure in kiln using the
recommended heating schedule.
Powder finished mold
with kiln wash.
Slump.
Best Mix Mold Mix
Developed by Fusers,
for Kilnformers
Worldwide |
