I can see straight away there are 2 errors which could have played a factor here.  Firstly you did not measure out the resin and hardner properly on scales or by volume (and using the correct mix ratio).  This means you could well have different amounts of dregs left in each pot meaning your mix ratio was out.  Secondly it sounds like you did not mix nearly long enough.  When mixing you can see the wispsas the two liquids mix.  They should be long gone by the time the resin is fully mixed.  We recommend mixing in one bucket for around 3 minutes, then transferring to a second mixing bucket and mixing for another 3 minutes.  That way you lesson the chance of unmixed resin being scraped from bucket onto the cast, and also the extended mixing time means, assuming you mix it properly, it should be mixed thoroughly enough.   The fact one of the casts is hard in one area but not the rest shows that some is mixed ok but the rest is not.  

You don't mention the curing temperature but you need to keep things 20C or thereabouts throughout the cure time.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

So we've been doing our first test of glass-case 50, and we bought the 500g kit which is already measured out.

Steps Taken:

1. Poured out the resin into a bowl - it had a lot of bubbles in it.
2. Put the bowl with the resin in it in a larger bowl and poured hot water around it (60 deg or so) and warmed it up to get rid of the bubbles.  This worked fine.
3. We prepared the moulds - we had 2 test moulds (a) was a small metal wire sculpture 2" high, 1.5in diameter, and (b) as just a figure in a cup 2" high, 2" diameter
4. Took the resin out of the warm water and immediately the poured the hardener in the resin and stirred.  The hardener when poured in showed very strong opaque wisps as it stirred in, it made the mixture almost opaque with the wisps following the stirrer as we stirred.  We mixed it fully as possible.
5. We poured the moulds - they were very wispy when we first poured and then they went beautifully clear.
6. After 1 week, the resin has not cured. Mould (a) is completely liquid, and when tipping the mould to one side, the resin flows around like honey.  Mould (b) is hard/tacky for the top 1" and appears to be liquid at the bottom.

What did we do wrong?  Was it not letting the resin cool before adding in the hardener?


Image 1: mould (a) shortly after first pour, note that the wisps have died down quite a bit but you can still see that the resin is not clear.

Image 2: Same mould 1 week later - resin is beautifully clear, but very liquid as shown by the tilt, actually more liquid than honey.