Hi,
one issue that all epoxies suffer from to a greater or lesser degree is exotherm.
When epoxy is mixed it starts reacting and releases heat as it does so. That causes the mixture to heat up and then it starts curing faster, releasing more heat....its a self heating
loop, and by the time it stops the epoxy is smoking and you'd swear its going to catch fire.
Epoxies meant for laminating, say boatbuilding, are mixed in small quantities are a quickly spread out into thin layers. Exotherm is not a problem, but if you mix up
a big batch and pour it into one big lump....then exotherm is very likely and will totally wreck the job.
Best to avoid any laminating epoxies....look instead for brands that are specifically for casting, they are better behaved.
Hi FHM - The one with lower viscosity is the better for your application. since you are going to add less then 10% epoxy to a bunch of cold sand, the sand will absorb the exotherm. But test a sample say 4 litres of "granite" and epoxy in an icecream plastic tub and if the tub does not melt then your on your way. Use the exact mix as specified do not change the mix ratios. Peter
Epoxy technical chart
Reply with Quote
