Talk Composites - The Forum for Advanced Composites

AS40 silicone vacuum degassing

http://www.talkcomposites.com/Topic36234.aspx

By dubster - 4/14/2020 1:23:06 PM

I would like to degass the AS40 silicone.  it is the first time I use this Easycomp material.  

 I am using a VE115SV 1/4HP pump.  It seems that the silicone isn't degassing completely. 

could it be that the pump has to less power to degass?  the silicone starts to bublle, but doesn't make the self collapse. 

pix of a sample i made

and the finished result
By dubster - 4/21/2020 6:01:22 AM

 
Hanaldo - 4/21/2020 5:51:45 AM
 
dubster - 4/20/2020 9:27:56 AM
It now makes the selve collapse, but it takes ages to degass it completely.  

in this times where materials aren't easy to receive, Is it a shame to use a first silicone (that degasses much faster) for casting on the visual side, let it cure and then use a second one 'to fill the space'?

both silicones have the same shore value...

Shouldn't be an issue if you get the timing right and pour the second batch of silicone when the first pour is still tacky. But this will always be a touch weaker than a single pour. Depends how many times you want to use the mould as to whether that will matter or not.


Thanks for the advice!!