Epoxy Gel time and Set Time Calculator
Epoxy gel time for a given hardener speed is temperature dependent. For every 18F (or 10C) the temperature changes the gel time will either be cut in half or doubled. If the temperature rises it will be cut in half and if it falls it will double.
We are providing here an interactive calculator where you can enter the data from either a data sheet or your own experience and it will extrapolate out gel and set times for the given temperatures you are working in or with.
Some IMPORTANT notes:
This is a “rule of thumb” calculation. While we have found this rule to be pretty accurate across a wide variety of resin systems before you make important decisions like when to turn off the vacuum pump or to demold, we strongly encourage you to do some tests or add in a safety factor.
Double check your resin’s data sheet for the temperature they are giving the geltime at, most are at 77F, some are not.
Some manufacturers will include the time at which the resin is “set”, this is not fully cured but often cured enough to allow some handling or to not allow the laminate to relax. This generally follows the same rule. Set time can also be referred to as tack free time. If determining a time to demold a part add a safety factor AND make sure you bring the temperature below the resin’s Tg or HDT (heat deflection temperature).
Keep in mind this applies to epoxy resins, not polyester resin systems that use MEKP initiator (catalyst)
If you have any questions about a this calculator or your application please contact us.
The Geltime and Set Time Graphs are downloadable as .png (image) files, scroll all the way to the upper right hand of the graph and there will be a blue arrow that you click to download the graph.