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HELP! Concrete Sealer Troubles

Patio White SpotsI resurfaced my stamped concrete patio this past week. I used the Behr family of products...Etching solution, Semi Transparent Concrete Stain (2 coats) and Low Luster Sealer. I followed all of the instructions on the containers, even allowing 12 hours between each process and coat. However, due to the humidity (Atlanta, GA), there appears to be moisture trapped underneath the sealer and there are white spots all over the patio (see attached pic). I just picked up a gall of of the Behr Concrete & Masonry Pain Stripper and will test it in a small area. However, if the descriptions on the container are accurate, it will remove more layers than just the top sealer that I want it to remove. Is there another trick or product I can use to avoid having to strip the entire surface and stain it all over again? Maybe something that will just impact the puddles of sealant so I can remove? Please advise ASAP!!


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Posted 2011-06-06T23:59:21+0000  by kel2 kel2

Hello Kel2!


Your project looks outstanding ... up to the Low-Lustre Clear Coat.


I love the color you added using Behr Semi-Transparent Concrete Stain ... you obviously prepared the surface well because the colors saturated beautifully.


I'm sorry to learn of your problem with the final step ... leaving milky pockets in the recessed creases in the stamped concrete.


What you've experienced is fairly common.


It is the result of the layer(s) of clear coat being applied too thick.


The product label suggests "several thin coats." 


When almost any water-based clear coat is applied too thick, the surface dries before the water can evaporate from the pocket of fluid underneath ... capturing the moisture and showing thru the dried surface as milky spots.


When applying this and similar products to an irregular surface, purchase a package of lint-free rags and wipe the excess in the creases after each coat ... allow each coat to dry the time designated on the label and then apply the next coat.


Several thin coats will give you the look and protection you desire.


Now, as for removing the existing problem areas ... you will need to use 400-grit sandpaper to break the surface in and around these milky pockets. Use your lint-free rags to wipe the excess, allow the pockets to dry clear, and then recoat the entire floor.


NOTE: I would not proceed with the stripper you purchased. You will undo your handy work all the way down to the stamped concrete ... essentially reversing ALL of the effort you put into making your floors beautiful.


Lightly sanding and then recoating the floor, although it is a lot of additional work, is your solution!


Posted 2011-06-07T13:31:01+0000  by Pat_HD_ATL

Thanks! I'll give it a try shortly and post the results.

Posted 2011-06-08T02:50:02+0000  by kel2



I  just experienced the same problem; however, I don't just have the "pockets" I have entire areas that look like they have a white, cloudy layer.  Should I sand the entire area or is there any other way to fix this?  Thank you.

Posted 2013-08-21T03:02:51+0000  by Triz

All water-based acrylics act this way until they are totally dry and fully cured. They are always milky looking in their wet or uncured state.  For example, if you read the label on clear acrylic caulks, it warns that it could be up to a month before they are fully cured and turn completely clear, If time restraints permit it, I would give it a week or two to see if the situation does not resolve itself. More aggressive measures can always be taken at a later time should it not dry clear.


Cool and damp locations, such as concrete on grade , can also slow this cure.

Posted 2013-08-21T21:41:22+0000  by ordjen

I agree with Ordjen. Just looks like the clear coats have not completely dried yet. Temperatures, humidity and the thickness of each coat will all greatly influence the drying time. I would suggest putting a fan in the area and give it as much time as it needs. By the way, you did an awesome job!

Posted 2013-08-23T12:05:25+0000  by Scorpioforu
Behr Technical Support says this is known problem that occurs when their water-based sealer is applied too thick or poured onto a surface and spread around.

The fluid settles into deeper creases in the surface and the surface dries before the captured fluid can dry ... leaving the white fluid beneath.

They recommend lightly sanding the surface to expose the undried milky white fluid and then wiping with a cotton lint-free rag.

Allow the residual to dry and then apply several thin coats ... allowing each coat to fully dry before applying the next.

You should be able to recapture the beauty of your floor, without the white residue beneath.

Posted 2015-12-08T21:37:48+0000  by Pat_HD_ATL
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