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Vinamold is by far the best and most widely
used hot melt system available. There are
others on the market but Vinamold gives the
most re-melts and has the largest number of
hardness grades available.
The biggest benefit of a hot melt is the
fact you can re-melt it should the mould be
damaged or no longer used and re-pour. The
second biggest benefit is the pricing! Vinamold
costs less than half that of silicone.
Care must be taken when melting Vinamold
as too much heat will burn it and shorten
its life (and number of melts!) but also give
of noxious fumes like a burning plastic.
It is made from Poly Vinyl Chloride and harmless
other than the risk of burns when using it
in a molten state. Since its melting point
is 150 Celsius or more it must be handled
with respect and heat resistant gauntlets
are best employed.
It works in a very similar fashion to silicone
except that instead of a chemical cure the
material loses heat and solidifies. A former
needs to be prepared slightly differently
however. It should be painted with shellac
and dusted with talc. Porous formers must
be completely dry or when the hot rubber hits
the cold damp surface, the water turns to
steam and makes small bubbles. These can be
repaired via melting the affected area and
reforming, but this is best avoided.
A two part mould is achievable by using shellac
and talc as a separation barrier. Dont
forget the keyways just as if you were using
silicones.
As the Vinamold is flexible you will need
a support case. Fibre glass will give the
longest life but plaster cases seem to be
the tradition, especially within ornate fibrous
plastering.
There is not much more to add about Vinamold
and hot melts other than to discuss heating
methods and melting points. The melting points
and pouring temperatures are different and
are shown in the table below for the three
popular grades red, yellow and blue.
To melt Vinamold and get the best life from
it you need a professional melting pot. These
are double walled and oil filled to ensure
good heat distribution and low risk of burning.
Larger units have quick melt and stirring
systems too. You can spend £12,000 on
this kind of kit, though the smaller units
can be bought for well under £1000.
Most people do not wish to spend this money
on Vinamold melting systems and opt for a
double walled vessel or a very heavy gauge
saucepan. Although you can melt Vinamold with
direct heat in this fashion we do not recommend
it due to risk of fumes and fire. If you must
melt Vinamold this way do it outside.
Please review the small table below to get
the right melting and pouring temperatures
for your Vinamold.
| Grade/Hardness/Colour |
Melting Point
(Celsius) |
Pouring Temp.
(Celsius) |
| Red (soft) |
150-170 |
140-150 |
| Blue (medium) |
150-170 |
140-150 |
| Yellow (hard) |
150-170 |
140-150 |
White (soft,
heat and
corrosion resistant) |
170 |
170 |
We have reproduced this in pdf format for
you to download and refer to. Do not reproduce
without prior permission from www.tomps.com:
Vinamold
Mould Guide
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