# Suggested Finish on New Concrete for Epoxy Later



## batman71 (Sep 6, 2012)

I have read elsewhere on this forum that new concrete should not be sealed or coated if the intention is to apply an epoxy after it cures.

Any recommendations on the appropriate finsh (i.e. smooth trowel, broom or other) ? It would seem to me that a broom finish would provide the best surface for the epoxy to adhere to.

If I do use a broom finish, would that eliminate the need to etch the surface?

Thanks for input.


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## Chris (Sep 7, 2012)

I would not recommend the broom finish if you are going to do epoxy, it wont get as smooth and etching is easy. Smooth finish will give the epoxy the best look.


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## oldognewtrick (Sep 7, 2012)

Be sure to allow for a proper cure before applying any type of coating and do a moisture test by tapping clear plastic over an area and see if you have moisture underneath after 24 hours.


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## batman71 (Sep 7, 2012)

I spoke with Sherwin-Williams yesterday and they confirmed that etching would be required even with a broom finish. Apparently, the etching has more to do with the composition of the surface as opposed to the texture.

 I have the latitude of waiting sveral weeks or even months before applying the epoxy. So, allowing it to fully cure and dry should not be an issue.


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## oldognewtrick (Sep 7, 2012)

I belive the cure standard is 28 days per inck of slab.


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## SeattleSurfaces (Nov 7, 2012)

Acid etching isn't an adequate form of surface prep to create the required profile you need to get an epoxy to bond well.

You really should grind or shot blast for best results.

With that said, a standard floor finish will be as good as anything and will be user friendly in the meantime.

Dave


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## pauloman (Dec 13, 2012)

the truth is that 90% of the DIY home epoxy homeowners just sweep and leaf blow their garages and get away with it. A contractor would never risk this!
Acid etching is still used by some contractors and homeowners (not many) - issues with flushed out acid on lawns and sewers.

Any finish but a really smooth one is fine. Epoxies are a surface bond so any texture is good. Acid etching textures are often not even visible to the eye.

All fresh concrete surfaces have a weak crust dirt, sand etc that floated to the top of the pour when the cement was put down. It is very important to remove this weak crust before applying any coating. This was commonly down with a stuff broom, but now generally with a good waterblaster.

for more prep type info - which no one seems to talk about - see www.epoxyproducts.com/floorlinks.html


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## havasu (Dec 13, 2012)

Powdered citric acid also works well for etching and doesn't harm the plants.


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## batman71 (Dec 14, 2012)

Thanks for the feedback!


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