HOW TO CHOOSE YOUR SILICONE    

Ok, so you have your project ready, you are off to go buy some silicone and dive right in….  Whoa!  Slow down, tiger….. There is a whole bunch of stuff you need to know first.

What are you doing?  Is it a big piece, a small piece? Are you making a mould or a cast?  Do you need to make a box mould, a brush-up mould, a matrix mould, a pour mould?  How much are you going to need to fill it?  Do you want a solid coloured, or translucent  silicone? Are you in a hurry or is time not an issue?  Will you need a long or short Potlife?  What sort of Viscosity is required? What Shore Hardness do you require in your finished piece? Do you need to worry about Elongation/Tear Strength/Tensile Strength?

Yeah, working with silicones is a bit like  doing high school chemistry all over again, but trust me, if you understand the basics, it will save you a lot of time, money and frustration.

Lets start with the Product Description. 

When you are searching a website for silicon moulding rubbers, you will usually find somewhere a link to a.pdf saying “Technical Data Sheet”, “Product Overview”, or the like.  In a catalogue there may be aTable giving comparisons between the products on offer.

Note that the information I am discussing here is NOT on the MSDS… (the what? I hear you say? It stands for the ‘Material Safety Data Sheet’- a topic for another time…).  

A Technical Data sheet will give you all of the relevant information you need about a product. Lets go through one step by step, just to give an example.

At the top there will normally be a Product Description.  This will describe the general characteristics of the particular silicone, its category and type, and an idea of its texture, hardness, mix ratio and suggested applications.

Here are a couple of examples I randomly pulled out of my file (you should always keep this info for future reference): Continue reading