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