Talk Composites - The Forum for Advanced Composites

Quick question regarding CS25 Silicone rubber

http://www.talkcomposites.com/Topic31651.aspx

By TURK - 1/15/2019 5:01:32 AM

Hi guys,

I've finally managed to mould two ( Offside & Nearside ) headlight cover moulds using EC CS25 Silicone rubber.
The quality and definition of the finish is superb!  BigGrin

While I've been busy working on the next stage of the procedure ..................  casting 'Vac-Cast Epoxy Resin' into the silicone moulds,  a week has elapsed.

Now my silicone moulds have built-up an oily residue inside them!?  >>



My question is .............  can I simply 'wash out' with just a damp cloth the oily residue?
Or should I be cleaning the residue off with EC Mould Cleaner?

Other option I've read about are - Soapy water
Or even,  talcing powder!?

And,  how will this effect my Vac-Cast Epoxy Cast?

Any opinions ( comments ) greatly received.



Many thanks

TURK
T4 Concepts
By TURK - 1/20/2019 3:44:12 AM

 
Matthieu Libeert - 1/18/2019 4:58:08 PM

Great to hear you like my tutorials, I have a couple of silicone tutorials coming in the next two weeks. 
I use AC silicone and the CC silicone. Did a pour of 5kg for the tutorials but still use the two cup system. As much as I've tried mixing everything in one cup I still have uncured silicone. on the bottom or sides. 
You could check when you remove the left overs from the cup and feel the bottom of the leftovers if it is still sticky or not Smile 


Thanks for the information Matthieu,  looking forward to your next silicone tutorials mate.
Removing the 'cured' silicone from the buckets after the pour ( the following day ),  didn't show any signs of tackyness. So it was well cured.  The overall colour of the mixed silicone looked to be uniform,  no streaks,  so my estimation would be that it was mixed sufficiently.  

But as you have mentioned,  and Hanaldo,  there may be a mixing issue .......................  even though it may not be apparent,  it's quite possible when mixing large quantities of silicone. 
In future,  I  will use the two cup pour method as per your recommendation  Wink


"Certainly no harm will come to the moulds by wiping down with warm soapy water so you try that to see if it is a residue from the VacCast pour."
I haven't cast the 'Vac-Cast Epoxy Resin' yet Warren, it's the result of the silicone moulds sitting idle for a week.  




TURK
T4 Concepts