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S34n
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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
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Lester Populaire
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+xHi 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 One is the mixing ratio by volume, one by weight. And 25 grams is a very small amount so if your scale only shows one digit this might be already quite off. And i never used any glass cast resin before, but as far as i understand you would be better of using the glass cast 3 as it has better self leveling properties.
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S34n
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Group: Forum Members
Posts: 18,
Visits: 54
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+x+xHi 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 One is the mixing ratio by volume, one by weight. And 25 grams is a very small amount so if your scale only shows one digit this might be already quite off. And i never used any glass cast resin before, but as far as i understand you would be better of using the glass cast 3 as it has better self leveling properties. Thank you replying My scale shows to about 4 or decimal points as in : 67.9321 they're really accurate for their size.
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oekmont
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If you mixed your ratio by weight, you should have used 24g (16:8) instead of 25g resin. Or 28g. 17:8 gives you almost 5.8% to much resin.for small quantities you should only use weights that can be divided through the mixing ratio without rounding.
I would not use a scale with that precision for resin. It would be a shame to ruin such expensive equipment or the granite instrument table it should be placed on for accurate measurements with resin. 1/10g is enough precision, even for smaller quantities.
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S34n
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Group: Forum Members
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+x[quote]If you mixed your ratio by weight, you should have used 24g (16:8) instead of 25g resin. Or 28g. 17:8 gives you almost 5.8% to much resin.for small quantities you should only use weights that can be divided through the mixing ratio without rounding.
I would not use a scale with that precision for resin. It would be a shame to ruin such expensive equipment or the granite instrument table it should be placed on for accurate measurements with resin. 1/10g is enough precision, even for smaller quantities.
means or where your numbers ( 24g 16:8) 28g 17.8 5,8) are from, I used this chart on the bottle, the scales weren't expensive they're just portable pocket scales but have a few decimal places. I'm new to this so please forgive my stupidity. 
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oekmont
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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.
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oekmont
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I saw in an other threat, that the 2:1 ratio is for volumetric mixing. 100:45 is of course far worse for small quantities. But if you can measure 1/10 you could use multiples of 10:4,5. However, the right amount for 17g resin would be 7.65g hardener, if I am not wrong again. That's 4,5% to much hardener if you use 8g, wich seems to much to me.
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S34n
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Group: Forum Members
Posts: 18,
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+xThan 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. +xI saw in an other threat, that the 2:1 ratio is for volumetric mixing. 100:45 is of course far worse for small quantities. But if you can measure 1/10 you could use multiples of 10:4,5. However, the right amount for 17g resin would be 7.65g hardener, if I am not wrong again. That's 4,5% to much hardener if you use 8g, wich seems to much to me. +xThan 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. +xI saw in an other threat, that the 2:1 ratio is for volumetric mixing. 100:45 is of course far worse for small quantities. But if you can measure 1/10 you could use multiples of 10:4,5. However, the right amount for 17g resin would be 7.65g hardener, if I am not wrong again. That's 4,5% to much hardener if you use 8g, wich seems to much to me. But y our right about the scales I apologise its 2 decimal places not sure why I thought it was more.
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Warren (Staff)
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If you are weighing the mixture, you MUST use the mixing ratio by weight which is 100:45 resin to hardener.
If you are measuring by volume you MUST use the mixing ratio by volum which is 2:1 resin to hardener.
Where possible, keep the maths simple by working with multiples or simple division of the mix ratio. That way you can calculate the correct proportions easily.
Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant
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S34n
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Group: Forum Members
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+xIf you are weighing the mixture, you MUST use the mixing ratio by weight which is 100:45 resin to hardener. If you are measuring by volume you MUST use the mixing ratio by volum which is 2:1 resin to hardener. Where possible, keep the maths simple by working with multiples or simple division of the mix ratio. That way you can calculate the correct proportions easily. Hiya Warren,thx for the reply This is whats confusing me, ml and g gives the same reading, i.e. if I pour 17ml of resin into a ml cup (the cup /beaker has been zeroed on the scales empty first) it will read 17g. If i need to use less than 25g which is the lowest amount on the bottle mix chart what should I do? Do I use the e.g. 16g x 45% math or the 2:1 method which i'm guessing would be 8 hardener for 16 resin ? so confused
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