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

Than these are no reliable scales. It's impossible that a pocket scale could be more accurate than 1, maybe 2 decimals(gramms).
If your resin has a mixing ratio of 2:1, I would recommend to only use a multiple of that (4:2 6:3 8:4... 16:8 ...). If you use other number for the first component it's likely, that the second component will not be an natural number. For example, 17g resin would need more than 8, but less than 9g hardener. Think of it, 8 grams component b at 2:1 ratio would need exactly 16 grams resin, not 17. The table lists rounded numbers to get to 25g. Wich is problematic at these small quantities.