Epoxy, Polyurea, & Polyaspartic Adhesion Tests with LATE ROLLOUTS

So for epoxy we'll roll them out at 30 minutes, polyurea: 25 minutes and polyaspartic: 30 minutes. Applying coatings too late can result in failure because the coatings may heat up

or thicken up, causing visual and physical characteristic changes.

When applied properly, the PSI results were all very similar and very high like a thousand plus PSI. It will be interesting to see if we get different results this time. So, let's head out to

the Coatings Corner and put them to the test.

Okay, all three coatings have been allowed to dry for 7 days. These are the coatings that were applied at the end of their working times. So, we're going to glue the dollies to them and let that dry for 24 hours and then we'll be back tomorrow to do the pull tests.

Again, this test measures the force required to peel the coating from the concrete or when the coating bonds well, the concrete itself will fail and break first.

Here the positester malfunctioned. So this data point is not meaningful and will be excluded from the final results. The positester was reset and recalibrated for the next reading.

Here you can see the roller lines between the left and right halves of each area, more so in the polyurea and polyaspartic. The left sides, which were rolled out too late, are a bit lighter in color.

Okay, let's review the results. Here are the average PSI readings of the coatings that were applied 5 minutes past their working times. Even when applied 5 minutes too late after the stated working times, all three coatings bonded very well. They all have high PSI readings. In fact, all of them resulted in concrete failure except for one where the tester failed.

So again, good coating adhesion is typically considered to be at or above 400 PSI. The PSI of the late working time applications did decrease, but not very much. Polyspartic decreased the most, but it still had a 991 PSI. I have to admit that I thought the results would be much lower than this. One contributing factor could be that the room temperature when we applied these coatings was 63° compared to the 75° that's on the technical data sheet. Colder temperatures generally increase working times. Also, keep in mind that high humidity does shorten the working times for polypartic and polyurea. I think we should try to test these again, but maybe wait until 10 or 15 minutes after the stated working time to see if we get different results.

Again, for a deeper dive into the differences between these three coatings, check out Chris Boxmeyer's article on our website. And I hope to see you again soon.