High humidity and urethane

[nkurz]

Hello --

We're midway through redoing our commercial floor. The floor was shotblasted, and we put down a single coat of light-gray epoxy from Epoxy-Coat last night. We are planning to top coat with a Low VOC Urethane from Legacy this afternoon. But the weather has turned, and it's going to be raining solidly for the next week: assume 55F and 100% humidity.

Is there anything we should do differently to account for this? Epoxy-Coat said to stick with 18 hours to recoat. I've got email out to Legacy but haven't heard back yet. I assume want to try to improve air flow and reduce humidity, but I'm not sure we can have much impact. Anything else we should try? A thinner coat? Add a thinner to the urethane? Something else?

Barring any better suggestions, we're planning to start rolling it on in a couple hours. Thanks for any quick thoughts!

--nate

 

[LegacyIndustrial]

Nate and I talked. He's off the ledge now.

 

[thegarageguy]

Oh yeah, there is a crucial step to take when high humidity sets before applying a urethane but since you are a Legacy client, he can let you in on it. Contractors in Florida have to do it regularly.....Don't like to step on any toes. Good luck

 

[dcs Inc]

Come on garage guy. Others wouldn't mind to know what to watch out for. Maybe scotty could chime in and let guys understand relative humidity, ambient temps relative to concrete and air temperatures, high to low temps when starting epoxy applications to push moisture back into the slab instead of pulling it out and creating bubbles, dew points, silicone..... OK, I'm being a smart arss. I just covered all this stuff in an epoxy class I just taught. This stuff isn't as easy as it seems. When all the stars are aligned it goes well. When they are out of whack, it costs you money. gene

 

[thegarageguy]

Ok, well it seems the Op most likely moved forward before I got to post. For anyone else who cares to listen, it's always good practice to solvent wipe your floor before applying polyurethane when the night before was either rainy or very humid. Just like your grass with it's morning dew, garage floors would be the same, just much more difficult to detect. If it's not done, the possibilities of blushing and peeling off like window tint are very likely.

 

[LegacyIndustrial]

Thanks boys. The OP had completed the epoxy and was moving on to the urethane.
The inclement weather was inbound but not upon them yet. Beyond potential moisture on the slab my main concern was loss of gloss. This was a California compliant (water based) urethane too.

They reported a successful installation.

 

[pop pop]

You're a real talker there Scotty!

 

[LegacyIndustrial]

Thanks Pop-Pop. I usually start losing my voice around 2:00 and struggle to the end of the day. Where in Ginny u from?

I grew up in Manassas.

 

[nkurz]

As Scotty updated, the topcoat went on fine. We did it yesterday afternoon, and the floor looked good and seemed dry this morning. The California VOC compliant urethane (HD30 on the Legacy site) doesn't seem to have any particular issues with humidity. It did not even start to gel while were were rolling it out. We're hoping to have a normal employee foot traffic on it tomorrow.

We've only done the first 1000 sq feet of 3000. The two main things we've learned so far are that flakes should be thrown as small pinches rather than large handfuls, and that tabular alumina is hard to keep from settling to the bottom in a bucket of thin urethane. But no outright failures yet. I'll write up a postmortem when we are done.

 

[LegacyIndustrial]

That urethane is quite unique. It has a nearly infinite pot-life yet it dries quite quickly and can be re-coated the same day it is applied.

 

[thegarageguy]

failures do not appear overnight...usually within a week or 2. Hopefully you are ok...good luck with the rest

 

[thegarageguy]

Scott, that HD30....is that a water based polyurethane?