Tips for Working with Time-sensitive Epoxy Resin
Some projects are time sensitive – and therefore require quicker processing time for the steps required. One of the challenges in any endeavor is speeding up any of the tasks in the process if possible. Curing epoxy resin more quickly may be accomplished if done correctly to help meet deadlines…
The epoxy hardening/bonding process relies on a correct mixture ratio of 1:1 hardener vs. resin, and though it may sound like a good idea to increase the hardener amount – this is ill-advised – and may cause parts of the resin to not cure at all or for parts to remain sticky indefinitely. The same is true of adding any additional elements to the mixture in an effort to speed up the process.
However, "Sunlight and temperature are the main factors that affect curing time of most epoxies. The warmer your epoxy mix, the shorter the curing time. You can manipulate epoxy curing by speeding up the reaction by adding heat or slowing it down by making the environment cooler," from DoItYourself.com. Conversely, you can extend the amount of time that epoxy may be manipulated by working in a cooler environment or by working in the shade.
Additive epoxy curing accelerators are available and may give a better finish when dried but beware as they make leave some yellow tint as a side effect of faster curing time. Accelerators must also be matched with the type of epoxy being used to maintain the integrity of the bond and finish.
An epoxy curing oven may be employed, but should really only be used after the mixture has hardened via its inherent curing process. (So not really a time saver)! These ovens are employed in specialty processes such as aerospace uses and utilize two-step curing systems – the second part of which is oven curing. Most art, DIY and non-industrial epoxy resin applications don’t require an oven – and frankly are better off without this step. Extreme temperature can, in fact, be detrimental to curing.
For most residential applications, the 24-hour curing time is fine for artistic and home project use; while a longer 72-hour curing time should be implemented for hardier business uses such as counter and bartop coatings. Remember though, in epoxy resin curing, heat is a byproduct of the process, and the polymer takes time to harden correctly. Working in a warm environment with warm materials can help move things along a bit more efficiently.