Talk Composites - The Forum for Advanced Composites

Casting Silicon bungs (Shore hardness 40)

http://www.talkcomposites.com/Topic5567.aspx

By Mick Dixon - 3/26/2013 2:43:08 PM

Good afternoon technical team, My project is to cast silicon bungs with two tube holes running through. One 4mm & one 8mm.

I have been sucessful on two trials and I wish to improve my methods. I have a workshop at my disposal and have created aluminium moulds

and a vacuum degassing chamber. I am however new to the business and require some guidence.

(1) What temperature should I store the silicon rubber?

(2) I find it difficult to decant the silicon from one vessel to the moulds. Is there a method to make it more runny?

(3) What is the ideal method to degas the mixture. Should I keep stirring the mixture and degas again?

You will see from the photo that the left hand bung contains air and the right hand bung does not.

Thank you , I welcome your idea's................Mick Dixon

We are already using your products
By matthieutje65 - 3/26/2013 10:24:01 PM

A Video-tutorial I've made some months ago, should give you some extra information.



To make it more runny, use heat.
Store it at +/-20 °C
Degass it with vacuum by doing multiple vacuumdrops and releases till there is no more air inside (movement)