This easy and cost effective way to make simple press-in moulds has become very popular over recent months. Used by the dental profession for many years for making dental impressions its potential as a general mould making material has only recently been realized.
The putty has the consistency of dough and can be easily pressed against almost any surface to make a realistic mould of the original. Its dental origins render it suitable for most food applications.
Because you only use the exact amount required to cover the object and make a small retaining lip around it , silicone putty is much more economic to use, than regular liquid silicones.
This is short article on how to make a mould rapidly with the easy to use Aldax Silicone Putty.
Making an Aldax Silicone Putty Mould
Step 1. Using an equal quantity of Part A and Part B Aldax silicone putty measured by weight or by volume, quickly knead the two together till evenly coloured.
Step 2. Roll the putty into a ball between the palms of your hand and then flatten it to approximately twice the thickness and width of the object to enable the object to be pressed into the putty and make a clear impression and still leave enough putty around the edge to contain the casting material. It is a good idea to lightly spray the object with a release agent such as a thin film cooking oil to enable easy release from the mould.
Step 3. Aldax Silicone putty has a work time of slightly over 3 minutes and cures in about 20 minutes to an hour. It should be noted that for casting with some resins it is advisable to leave the object in the mould overnight to ensure the mould is fully cured. Curing can also be speeded up by using heat.
Curing with Heat
Remove the original item, place the mould on some aluminium foil and place in the centre of a normal oven, not a toaster oven, at least 15 to 20cm away from the closest heating element. Heat the mould at 150 to 200°C for one hour.
It is possible to use an oil heater or hair dryer but this takes much longer than an oven and is dependent on the size and thickness of the mould. I would always post cure a mould with heat that is intended to be used for food items to ensure positive curing.
Care of Food Moulds:
Never use a mould that is intended for use with food items for any other purpose under any circumstances. Do not use a mould release with food items. Use the usual sanitary care and wash the mould after food use, in warm soapy water and let dry. Moulds used for food can be used in an oven for temperatures up to 200°C for baking, making sweets and chocolates.
Low temperature melting alloy metals can be cast into silicone putty moulds as long as temperatures do not exceed 200°C Check the metal manufacturers MSDS sheets before use to ensure that you are conforming to his recommendations regarding temperatures, toxicity and methods of handling etc. Always dust moulds with Graphite or Talc before use and wear appropriate clothing together with eye and hand protection, essential when working with molten metal.
It is a good idea where possible to leave the original in the mould when storing in a cool, dry area to help the mould retain the original shape without distortion.
Mould Making Problems
(1) Silicone putty can become very warm and become harder if you take too long to knead the two parts of the putty promptly. Remember that the working time of the putty is 3 minutes.
(2) If the silicone putty has streaks of colour, seems soft and does not cure properly, you did not need the two parts together till it developed a smooth even colour.
(3) If the resin casting material comes out of the mould with a rough texture it is probably because the mould was not cured properly and gases still contained in the mould have caused air bubbles min the casting material.
Warranty: The recommendations that are given here are only intended to serve as a guide. As with all industrial products the user should determine the suitability of the product for its intended use and must assume all risk and liability in connection therewith. Our risk is limited to the replacement price of the product
Copyright © 2011 Aldax Enterprises Pty Ltd