I am researching possible ways to permanently transform a liquid to a solid which would have a strength of around 3-4,000 psi. I have been experimenting with polyurethane that will have the required strength but i was hoping to find something that will have a somewhat low viscosity for at least a few hours before it cures or hardens. what i am looking for is either a solution like polyurethane but that will stay at a low viscosity for a considerable amount of time (5 hours) before turning solid. Another possible solution would be something like electrorheological fluid, in which i could push a button (sending an electrical current) and the liquid would become solid. The only problem with electrorheological fluid is it is only temporary. Also these liquids will be at extremely high pressures (5000 psi), is it possible to induce some kind of chemical reaction through pressure, transforming the liquid to a solid?