Hello, I'm Travis Negard with UltraDurable Technologies, and welcome to the Coatings Corner. As a coatings manufacturer, I have found that to get the most out of any coating such as hardness, chemical resistance, and overall performance, you need to start with 100% adhesion. Good adhesion relies on many things: foremost, preparation processes, but also environmental variables, mixing and application processes, and the chemistry or coating type. So, in this video, we're going to test the adhesion of three different high-solids coatings, epoxy, polyaspartic, and polyurea.
Chris Boxmeyer's recent article addresses many of the differences between these three coatings, so I encourage you to check that out. You may have heard that polyureas and polyaspartics just don't bond directly to concrete like epoxy does. Is this true? I guess we're going to find out.
Let's head over to the Coatings Corner and put these products to the test. We mixed the MC Epoxy, UDT Polyurea, and Ultraspartic coatings according to the directions and immediately applied them to concrete that was prepared to a surface profile of 2 to 3. All three coatings were applied at a consistent thickness of 6 ms.
Hi, we're back. All three coatings have been allowed to dry for 7 days. So, we're going to glue the positest dollies to the coatings and let them dry for 24 hours and we'll come back tomorrow and do the pull test.
For the positest to work properly, you need to start with a clean surface.
The positest dollies are applied to the coatings with a two component epoxy glue. We wipe off the excess glue and then allow the dollies to dry for 24 hours.
There is a lot of roller lint on these small test area, so we made sure not to glue the dollies on top of the lint. For this test, we glued the three dollies to each coating type.
Okay, we're ready to start the pull test. We'll be recording the PSI number at the time that the dollies pop free. And we'll also record if the concrete fails or if the coating peels.
So, here's the PY test in action. You can see the PSI number gradually increasing.
Wow, there it popped at 1,114 PSI. That's a very high reading. You can see that the concrete failed, too, which is great. Now, we will proceed to check the rest of them and record the results.
On this one, the glue failed rather than the actual coating or the concrete. So, this one will be excluded from the final results.
Let's review the results. Here are the average positest readings. You can see that all three have very similar results. In fact, all of them resulted in concrete failure except for one where the glue failed to bond to the polyaspartic. Good coating adhesion is typically considered to be at or above 400 PSI, especially when the failure mode is due to substrate failure. That indicates that the coating has bonded well and can withstand significant stress.
In the next video, we're going to apply all three of these coatings again, but this time 5 minutes after the end of their respective working times.
Maybe this will help us understand what causes coatings to fail and even more so if polyureas or polyaspartics may be more prone to failure than epoxies.
See you again soon!
