June 19, 2018
Measuring out the components directly into the mixing pail is bad practice. One reason why this practice is not recommended is because the residual epoxy from the previous mix will result in subsequent off ratio mixes that impact the product application performance and potentially the physical properties of the finished floor.
In a recent experiment conducted here at Dur-A-Flex, the average residual epoxy collected from the walls and bottom of a 5 gallon mixing pail was approximately 13 fluid ounces (medium viscosity epoxy, 74°F initial product temperature, 6 second timed pour outs). Significant off ratio mixes can occur when the residual epoxy in the mixing pail is combined with low accuracy measurement techniques such as a depth stick or screws in the pail wall to determine the volume of components added.
The best practice when preparing epoxy is to measure out the hardener and resin into separate measuring containers that have molded volume marks in the container wall (printed on marks are typically marked as “approximate”). The accurately measured components can then be combined in a mixing pail, (adding the hardener first, followed by the resin), taking care to pour the components into center of the mixing pail.
The printed on marks for the container on the left are approximate while the container on the right has marks that are molded into the plastic and more accurate.
A paint stick should be used to scrape the measuring containers clean, and always use the rim of the measuring container to scrape residual component off the paint stick into the mixing pail (never use the rim of the mixing pail). The epoxy should be mixed using a Jiffler™ type mixing attachment on a slow speed drill at 350-450 rpm for 3 minutes to completely blend components without entraining air into the mix.
These best practice guidelines are designed to deliver reliable product performance by ensuring properly mixed epoxy at the specified mix ratio across all batches.