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Cure time dictates how long you must wait before removing Using WEST SYSTEM Epoxy 59 Epoxy Temperature Cure time after mixing Solid Finalcure phase Gel Initial cure phase Minimum Recommended Temperature Tacky Tack free RECOAT CURE & PREPARE SURFACE Liquid Open time Figure 8-3 As it cures, mixed epoxy passes from a liquid state, through a gel state, to a solid state. Cure time is shorter when the epoxy is warmer. Cure time is longer when the epoxy is cooler. 8 clamps, or before you can sand or go on to the next step in the project. Two factors determine an epoxy mixture's open time and overall cure time��hardener cure speed and epoxy temperature. Hardener speed Each hardener has an ideal temperature cure range (Figure 8-1). At any given temperature,greek fraternity bench manufacturer each resin/hardener combination will go through the same cure stages, but at different rates. Select the hardener that gives you adequate working time for the job you are doing at the temperature and conditions you are working under. The product guide and container labels describe hardener pot lives and cure times. Pot life is a term used to compare the cure speeds of different hardeners.
It is the amount of time a specific mass of mixed resin and hardener remains a liquid at a specific temperature. (A 100g-mass mixture in a standard container, at 72��F). Because pot life is a measure of the cure speed of a specific contained mass (volume) of epoxy rather than a thin film, a hardener's pot life is much shorter than its open time. Epoxy temperature The warmer the temperature of curing epoxy, the faster it cures (Figure 8-3). Curing epoxy's temperature is determined by the ambient temperature plus the exothermic heat generated by its cure. Ambient temperature is the temperature of the air or material in contact with the epoxy. Air temperature is most often the ambient temperature unless the epoxy is applied to a surface with a different temperature.Resistant to erosion composite panel Generally, epoxy cures faster when the air temperature is warmer. Exothermic heat is produced by the chemical reaction that cures epoxy. The amount of heat produced depends on the thickness or exposed surface area of mixed epoxy. In a thicker mass, more heat is retained, causing a faster reaction and more heat.
The mixing container shape and mixed quantity have a great affect on this exothermic reaction. A contained mass of curing epoxy (8 fl oz or more) in a plastic mixing cup can quickly generate enough heat to melt the cup and burn your skin. However, if the same quantity is spread into a thin layer, exothermic heat is dissipated, and the epoxy's cure time is determined by the ambient temperature. The thinner the layer of curing epoxy, the less it is affected by exothermic heat, and the slower it cures. Controlling cure time In warm conditions use a slower hardener, if possible. china wpc hollow flooring manufacturerMix smaller batches that can be used up quickly, or quickly pour the epoxy mixture into a container with greater surface area (a roller pan, for example), thereby allowing exothermic heat to dissipate and extending open time.
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