Latex – How does it work?
The Kwik-Mold Latex series provide the mould maker with all the viscosities of latex needed to make moulds by dipping, brushing and a very thick form for applying to vertical surfaces or for rapid build-up of flat back moulds – #74.
Kwik-Mold 70 is a one-part, dipping or
brushing latex. It is a 60% dispersion of natural latex that vulcanizes at
room temperatures. It has a strong odour of ammonia and should be used in
We use Kwik-Mold 70 for the first 3 to 5 coats to be
brushed on models with a lot of detail, to ensure that we retain maximum
detail in the mould with this un-thickened natural latex. Brush with a
stipple action to lay an even coat and eliminate as many air bubbles as
Kwik-Mold 72 is a thickened form of latex
designed for use on all subsequent brush coats, after using Kwik-Mold 70 for
the primary coats. It provides an ideal way of building up coat thickness as
rapidly as possible, while still retaining maximum strength in the finished
Kwik-Mold 74 is a filled form of latex for
use on vertical surfaces where its thixotropic character enables rapid
application of rubber that will stay where you put it or for rapid build-up
of final coats of flat back plaque moulds.
Latex uses: Ideal for casting plaster,
concrete but can also be used for limited casting of some resins. As a white
brush-on liquid, after multiple applications it builds up to a mould
thickness of 1 to 3mm that air vulcanizes to a light amber colour. This forms
a very tough, blanket mould with great elasticity.
Latex has a better tear strength than all synthetic
rubbers and is preferred by the concrete and plaster shop industry when used
as a sock mould or one that peels off a casting, just like you pull a sock
off your foot. However the polyurethanes are catching up fast and are in use
for concrete press moulds, where a final thickness can be brushed on in half
How to seal your model
Wherever possible we endeavor to
make our models in plaster. Plaster is porous and does not need a sealer or
release agent. Also latex peels off the model quite easily.
This does not apply to all
porous items particularly wood, which due to its fibrous nature can cause
problems unless you seal the surface. You can seal with several coats if
paste wax or by spraying with lacquer, shellac followed by a coat of release
Wax, glazed ceramics or glass do
not need sealing or application of a release agent. Avoid petroleum-based
products, solvents and oils as they are not compatible with latex and will
cause its degradation over time. If in doubt test a small area to see if it
Making the latex Mould
Latex makes the thinnest, most
elastic and strongest mould of any type of mould making rubber. It can be
polled over relatively large undercuts when releasing the model without
strongest moulds are made by brushing on thin layers of latex. The number of
coats can vary from 8 to 20 or more depending on the size and purpose of the
mould. A simple mould of a chess set piece about 15cm high would normally
take about 8 to 10 coats, each coat applied, then let to dry in a warm area
until the white colour disappears before applying the next coat. About an
hour or so between coats would be normal. To speed things up you can use a
fan driven radiator or hair dryer to dry the water in the latex. The colour
changes to an amber rubber colour.
Latex cannot be poured or
applied in thick sections, it will not cure. Your mould when completed will
be quite thin and if above say 15cm in height will require a back-up mould to
support its shape when casting.
To assist beginners, we have produced a kit based on our methods here at the factory for making a plaque mould. Click here for more information
ã Copyright 2006 Aldax industries Pty Ltd www.aldax.com.au