Talk Composites - The Forum for Advanced Composites

condensation silicone

http://www.talkcomposites.com/Topic6160.aspx

By themudhutt - 5/20/2013 4:06:38 PM

I need some advice about the silicone I am using to make my moulds. According to the 'tub' the mix is 100-5, according to the paperwork the mix should be 100-2.
We have found 100/5 to be very firm and now the corners of one mould has split. The latest batch of moulds we mixed to 100/2, this has still not firmed fully after 36 hours, its getting there just slowly. We are hoping this mix will be more user friendly.
Can you advise which if either is the best mix ?
Can you advise on another type of silicone perhaps, we make small 'fairy doors, rings houses' etc .The moulds are used multipule times daily. We cannot afford the thousands for a tooled mould but would like to use a silicone 'like a baking tray'. 
You will have gathered we are new to this but nevertheless determined to get it right. 
Any help very gratefully received
By Warren (Staff) - 5/21/2013 1:09:18 PM

The mix ratio is between 2 and 5 % catalyst. 

You can vary the amount between those figures to give you what you want in terms of cure time.

You might want to look at our Addition Cure Silicone Rubber as it offers slightly better performance (once cured) than the condensation cure.