Polyurea adhesion question

[scottb1469]

After a lot of research and numbers crunching I stumbled onto some info that I’d like some forum input on. Specifically that because polyurea has such a rapid cure rate that it doesn’t have enough time to soak into the concrete and adhere as well as epoxy does. I didn’t know if this is true or not, as I read it on the interwebs so I thought I’d ask here. Another person suggested that the best solution would be a base of epoxy topped with a clearcoat of Polyurea, presumably because the epoxy adheres better and is a thicker base but the polyurea is uv resistant and doesn’t scratch as easily?

I was all set to order up the polyurea until I saw this this morning. But I’ve also seen countless reviews by people who love their polyurea floors. My head is spinning lol.

I have a 600 sq/ft slab that was poured in sept 2017 and I just etched it. I live in a warm climate and it doesn’t matter to me if it takes a day or 7 to complete this, the long term results are most important to me.

What do you guys think and does anyone have direct experience with this type of “hybrid” floor? Thanks everyone

 

[notchy12000]

I would be interested to hear the experience with the hybrid approach.

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[Shea]

I think you may be confusing the fast curing high solids 2-part polyurea polyaspartic coating that are used commercially for professional floor installations with the single-part polyurea coatings.

Generally, the type of polyurea and/or polyaspartic coatings with the faster cure rates you are referring to are the 2-part, very high to 100% solids product that is used by commercial installers. These installers always grind the concrete to a CSP-2 or greater profile to promote the best penetration of the coating. They never acid etch. The faster cure rates allow them to grind and install a minimum of a color base coat, flakes, and clear coat all in one day. You can walk on it that evening and drive on it the next.

There had been some debate for a while regarding how well these type of systems would adhere to concrete (the first initial coat) compared to a typical epoxy coating that involves an epoxy primer. While there were some cases of this being a concern early on with these coatings, application techniques, concrete prep, and product formulations seem to have negated these issues. A proper epoxy system will arguably have better adhesion over the fast cure systems, however, when you compare the adhesion numbers, both exceed the amount of force that is required to pull a coating off the surface of concrete (greater than 300 PSI) and would be pulling concrete up with the coating if this were to happen.

Many installers like to use what they call a hybrid system. They can make it sound like its their own proprietary blend of components that makes their installations better when essentially it's just an epoxy base with a polyurea or polyaspartic topcoat. These are popular because they provide a thicker epoxy base and also promote better adhesion of color flakes for a full flake floor. The high solids polyaspartic polyurea clear provides a faster curing top coat and requires less applications compared to a polyurethane clear coat. You can also walk on it within a few hours. These type of systems are also popular for moisture mitigation in cases where an epoxy moisture barrier primer needs to be used.

Typically, the one day polyurea polyaspartic coating systems are more expensive due to the cost of the materials. The advantage for the customer is that everything is done in one day. If you don't need to have your garage back to service in one day, the hybrid systems are generally a little less expensive and they provide a for thicker overall coating.

The single-part polyurea concrete floor coatings are close to providing similar protection as the high solids 2-part commercial coatings, but they are not equivalent. Regardless, they are still excellent and available at a lower cost. They do not cure as fast as the high solids commercial polyurea polyaspartic coatings either. This is why they are so much easier to use in a DIY installation and why they work well for most acid etched applications as well as grinding. You can use a single-part polyurea for your complete coating system or you can create a thicker build system with a hybrid of an epoxy primer and high solids epoxy base coat with a single-part polyurea clear top coat.

 

[scottb1469]

Shea,

Well that answers that! What a very thorough and easy to understand response. Thank you for taking the time to write such a detailed reply, I really appreciate it.

 

[Shea]

YW... coatings can be confusing

 

[LegacyIndustrial]

Prime, prime, prime.

 

[Armorpoxy]

We carry all of these products and they all have different benefits. As a general rule a single coat hybrid one part polyurea like our SPGX would be the best low cost, but not as thick option. Next step up would be our 3 layer 100% solids epoxy system with military grade topcoat. Both of these are very easy to apply and fairly forgiving. We also carry Spartacote industrial grade polyaspartic but we don't recommend it unless you need low temp curing or very fast drying.

All of these types of coatings we have never had an adhesion issue with. Shea's comments are right on.

Our only comment about mixing different products or brands on multi layer coatings is that if you do have a problem you won't have a warranty due to the mismatch.