Slab Prep Question

[mopar440_6]

Well, the concrete was poured over a week ago in my 50'x60'x14' shop. I will be coating it within the next month (after full cure) but at this point I'm still undecided for the floor coating. It will be a densifier followed by either Nohr-S, Rust-Bullet or SPGX. Pictures of the build can be found here: http://www.garagejournal.com/forum/showthread.php?t=305797

I know these coatings don't require grinding, however, there are still some rough patches from the power trowels. There are little ridges sticking up above the level of the smooth parts that break off relatively easily. I think the ridges are from concrete sludge getting stuck to the outer ends of the trowel blades and slinging off. Also, there are little piles of hardened concrete dust around the saw cuts.

So, my question is how should I prepare the slab without completely opening the pores of the concrete? Should I rent a floor polisher with a 60-100 grit disc and sand it? Should I just try to get a scraper and scrape the concrete until it looks smooth?

I'd appreciate any advice.

 

[Garage Flooring]

Speaking for Rust Bullet over a power troweled floor. More often than people realize there is a sealer on these floors. I would test adhesion first. Happy to send you a 1/4 pint. Just PM me. If adhesion is good, you don't need to grind but you certainly can.

 

[Trey T]

"Sealer" as in chemical mixed solution that they spray on while troweling?

 

[mopar440_6]

Speaking for Rust Bullet over a power troweled floor. More often than people realize there is a sealer on these floors. I would test adhesion first. Happy to send you a 1/4 pint. Just PM me. If adhesion is good, you don't need to grind but you certainly can.

Justin, I've emailed you a couple times over the past few weeks. Per your instruction, I made VERY sure that no sealer or cure-n-seal was used on the slab.

 

[Garage Flooring]

Justin, I've emailed you a couple times over the past few weeks. Per your instruction, I made VERY sure that no sealer or cure-n-seal was used on the slab.

PERFECT. On GJ i never know 'real names' so sometimes emails, PM and posts its hard to tell who is who

 

[LegacyIndustrial]

Well, the concrete was poured over a week ago in my 50'x60'x14' shop. I will be coating it within the next month (after full cure) but at this point I'm still undecided for the floor coating. It will be a densifier followed by either Nohr-S, Rust-Bullet or SPGX. Pictures of the build can be found here: http://www.garagejournal.com/forum/showthread.php?t=305797

I know these coatings don't require grinding, however, there are still some rough patches from the power trowels. There are little ridges sticking up above the level of the smooth parts that break off relatively easily. I think the ridges are from concrete sludge getting stuck to the outer ends of the trowel blades and slinging off. Also, there are little piles of hardened concrete dust around the saw cuts.

So, my question is how should I prepare the slab without completely opening the pores of the concrete? Should I rent a floor polisher with a 60-100 grit disc and sand it? Should I just try to get a scraper and scrape the concrete until it looks smooth?

I'd appreciate any advice.

Why would you not want to open the pores?
That is what you are supposed to do.
Use the Diamabrush and be able to sleep at night.

 

[mopar440_6]

Why would you not want to open the pores?
That is what you are supposed to do.
Use the Diamabrush and be able to sleep at night.

Just a bit unnerved by grinding on a brand new floor. I was under the impression that being a virgin slab, the pores would already be open enough to promote good adhesion. Should I plan to grind it?

 

[LegacyIndustrial]

That is the furthest thing from true.

Coatings need to get a lock to your floor. Coatings do not like smooth.

Believe me if i could save a days labor for a crew of three by omitting grinding a floor i would!!!

Sent from my iPhone using Tapatalk

 

[Armorpoxy]

You may want to just use a very small hand grinder if you want to knock off high spots. If you are planning on doing a clear floor grinding if not done right, or with the wrong diamond size will leave scratch and swirl marks which can show through. When we do clears we grind to a minimum of #120 diamonds just to be sure.

SPGX doesn't require any grinding or prep other than power washing.