RESIN DOES NOT GEL
You might have forgotten to add the catalyst. Or possibly the resin or the hardener is old and time expired (24 - 36 months, depending on how they have been treated).
Air has inhibited the curing or perhaps not enough catalyst was added. Seal off the air with a layer of cellophane while curing. Or, wash surface with acetone, then buff and polish, or recoat with a heavily catalysed resin. A layer of ‘Norski Doming Resin’ completes a Kleer Kast moulding the best – it seals it and locks off the casting.
IF A CASTING STICKS IN THE MOULD
Insufficient care has been given to putting release agent into the mould. If possible, place the casting in boiling water for ten minutes then place in cold water; do this twice. The change of temperature will cause the resin to shrink, and it will then come out of the mould. If the worst comes to the worst, you may have to destroy the mould.
CRACKS IN THE HARDENED RESIN
To much catalyst, or use of embedded objects with a different expansion and contraction rate to the resin (glass chunks will cause cracking if embedded). Use less catalyst, or cool the mould in water during the cure, but wrap up the embedment in foil or other waterproof material to protect from moisture.
Caused by water or moisture in the work, embedded objects must be absolutely dry. Possibly also, work in a drier atmosphere.
Caused by air trapped in the resin. Mix resin carefully. Remove bubbles before hardening when you see them, by piercing with a tooth prick or needle, or even with a gentle stir of the recently poured casting. Move embedded objects round to make sure no air is trapped, a trick to make sure they are completely covered is to soak objects beforehand in catalysed resin.
This can happen in thin areas and is usually due to uneven application of resin. It can also be a symptom of a pour that has become exothermic during curing.