Alginate is an exceptional mould making material being unprecedented in terms of detail and speed mix the powder formula with water it will begin to set immediately spread the mixture evenly with a spatulaonce the mixture stiffens and no longer spreads evenly you have reached your working time which is approximately 2 3 minutes after this it will become too firm to work with alginate sets quickly once youve reached the end of your working time it will set in as little as 5 minutes once