EM-8000CV + 5% Crosslinker Durability Retest after 4 Months

[John TenEyck]

Back in March and April I posted chemical durability test results on various finishes, one of which was Target Coatings' EM-8000CV. The results on EM-8000CV + 5% crosslinker showed permanent damage from hot water and to a lesser extent from bourbon and Windex. Even at 10% added crosslinker hot water caused permanent damage.

Today I retested the EM-8000CV + 5% crosslinker against hot water and bourbon. Neither had any effect. In the photo below you can see the effect hot water, bourbon, and Windex had from my April testing. The hot water damage is easy to see in the upper center section; the bourbon is on the lower left and the Windex the lower right. Today I did the testing just below the hot water ring you see. No effect from either.





When I did the original testing all specimens were allowed to cure at least 7 days at 70F prior to testing, which is consistent with what TC says is required for a full cure. Today's test results show that the finish continues to cure for some period of time beyond 7 days and the increased level of cure resulted in much improved performance.

The question now is how long does it take to achieve the improved level of performance? I have no idea. Oil based varnishes can often take a month, maybe more. One of the hoped for advantages of waterborne products is the ability to put it to use without waiting that long but there's no way of knowing without further testing. While encouraging that EM-8000CV + crosslinker does reach a high level of performance at some point, that performance is still no better in these tests than EnduroVar after 7 days of cure. But it's good to know that the EM-8000CV + 4% crosslinker I used on a dining room tabletop before I did the testing should be more durable now than when I delivered it.

[roger wiegand]

Thanks for the followup, it's good to hear that it does eventually toughen up.

[Patrick McCarthy]

John, thanks to you and also Prashun for sharing the testing results. Later this year i am going to spray new maple kitchen cabinets (which i still have to make), so this information is timely.
I would be tempted to try replicating your testing, but i foresee problems trying to keep the single malt scotch in a glass long enough to test anything but my thirst . . . . Obviously you have more self control than i . . . .

Again, thank you for sharing. Patrick

[Prashun Patel]

My testing was not nearly as extensive as John's. but I will say that I've done a neighbor's kitchen table (June 2020) and my own kitchen table (March 2021) and island (March 2020). All have held up very well. We're pretty good about getting after messes, but we've had a few parties and spills and it's fine. The flat and satin sheens are what I have experience with. These are also pleasingly resistant to scratches.

[Marty Schlosser]

John and Prashin,

I've conducted similar tests myself in the past, so I was quite surprised with the results you had published last spring, as mine were more in line with those John's reporting now.

Thanks for the latest info.

[Jeff Roltgen]

Today's test results show that the finish continues to cure for some period of time beyond 7 days

It's worth noting that catalyzed finishes don't ever stop "curing" or "cross-linking" 100%. This is why you found cracking/crazing issues on solvent-based catalyzed finishes that were applied too heavily in the past. As I delve deeper into the latest and greatest of the water based finishes with catalyzing options now as well, guess what? I'm reading the same warnings. Do not exceed 2-3 coats, or a given thickness, depending on the brand. I expect the results would be the same - cross linking is exaggerated by the thicker finish build, and molecules eventually keep pulling tighter together, to the point they crack. I've seen examples that had over 1/4" of exposed wood between the thick, over-cured flakes, especially on a desk that sat in direct sunlight 8+Hrs a day.

Conclusion:
- Not terribly surprised you're seeing improved durability, as this is evidence that indeed, it does not come to a complete halt at 7 days = it's firming up all the more.
- Double-check all documentation on these new finishes for maximum coat thickness.

Thank you for the testing and report!

[Jim Becker]

FYI, Jeff is in process of developing a new formula for the 8000cv and crosslinker, according to a post yesterday on Instragram. One of the things he mentioned was eliminating the need for isos to increase safety. (development work on new formulas for other products, too)