Talk Composites - The Forum for Advanced Composites

Glass cast 10/50 epoxy resin/Silicone mould ratio maths

http://www.talkcomposites.com/Topic32356.aspx

By S34n - 3/17/2019 5:31:35 PM

Hi all, Thank you for any help in advance,
I've asked this kind of question before and unfortunately once again I've let my head confuse me.
For the Glass cast 10/50 epoxy resin ratio maths it gives 2 options 100:45 or 2:1 
1/  100:45  surely wont be the same as 2:1 as 2:1 is half;  so if one (2:1 ratio) is instructing half but the other (100:45) when worked out isn't half how will it cure correctly or the same if they're different measurements/amounts ? 
2/  Why is there 2 ratio options to choose from? 
3/   Can you use the 2:1 ratio say for lower and higher amounts for example if I poured:-   
200g resin :  would it be 50g hardener 
or
10g resin : would it be 5g hardener ?
4/ I have attached some photos whereby the surface isnt smooth I used the mix ratio chart and 25g  17g:8g ratio  to the absolute dot.
 
My next question is:
How do I make a mould for something like this which has two sides to it using the cs2 condensation cure silicone mould rubber 100:5 ratio would I need two halves of mould or 1 mould?:


Thank you so much for any help and I apologise if this is too long or in the wrong part of the forum
Kindest Regards
Sean
By S34n - 3/25/2019 12:17:57 PM

 
Warren (Staff) - 3/25/2019 11:22:05 AM
At a 25g batch size i would want to be using jewelers or weed smokers similar precision scales that can give you at least one or two decimal place accuracy.  Then just round to the nearest decimal place you can measure to.  eg if you have 2 decimal places, use those figures as is, if your scales are 1 decimal place then round to 17.2g and 7.8g respectively.


Ok thanks warren appreciate your time