# what kind of concrete or mortar?



## look171

Is there a special concrete use for kitchen countertops? How is it that they can get it so smooth? It sure feels like steel trowel stucco. I like to use the same material for the nosing or cap of an out door fireplace 3" thick and 4" wide. I was thinking of using regular spec mix and after it cures use some kind of bonding plastic cement or smooth stucco to fill the small little holes. I do not want it flat and straight but like to have that smooth finish. Any ideas? Thanks

Jeff


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## CJKarl

There are a couple counter top masters in here. I'm sure they will fill you in. Being outside and not being perfect may be a very good place to learn something.


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## neolitic

Gene Carp is in the concrete top business,
right now he's honeymooning in Rome. :clap:

Mean time you might search some of his threads.


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## 6stringmason

You can use quikcrete, but you need to vibrate the hell out of it to get all the most of the pinholes out. I find it entraps alot of air.

For a more smooth finish and less pinholes to fill in, use your own mix. Follow the 1/2/3 formula, but make it with a high slump. It'll vibrate easier and get more of those pesky pinholes out.

You could also use a water reducer like alot of us use in our mixes. Makes it very workable.

To fill in the pinholes afterword, just use a slurry of cement, acrylic, and water. Add coloring at the same ratio if needed.


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## look171

CJKarl said:


> There are a couple counter top masters in here. I'm sure they will fill you in. Being outside and not being perfect may be a very good place to learn something.


 
This is for my own home. If it's for a client, I would have my countertop guy done with it already. He's a nice guy but intense. He would not tell me what he uses and everything is a big secert all the way down to the sealers that he uses. sometimes it makes a big pain in the rear when I have to sell or educate clients. Like I really have time to take his business and starting pouring counters. Thanks again.


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## look171

6stringmason said:


> You can use quikcrete, but you need to vibrate the hell out of it to get all the most of the pinholes out. I find it entraps alot of air.
> 
> For a more smooth finish and less pinholes to fill in, use your own mix. Follow the 1/2/3 formula, but make it with a high slump. It'll vibrate easier and get more of those pesky pinholes out.
> 
> You could also use a water reducer like alot of us use in our mixes. Makes it very workable.
> 
> To fill in the pinholes afterword, just use a slurry of cement, acrylic, and water. Add coloring at the same ratio if needed.


 
Which Quickcrete? will a regular concrete vibrator do the trick? what is the 123 mix and if you would let the secert out? OK I am a bone head, but at last, what's acrylic? Like an add mix, a bonding agent? Sorry, My concrete experience goes as far as building forms call the truck and pour simple foundations. Most of the time, I have the subs do that. 

I will search but I am kind of new to this computer forum thing. thanks

Jeff


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## 6stringmason

1 part cement 2 parts sand and 3 parts agg.
The acrylic is a bonding agent and dries up a bit faster than just water slurry, reducing the waiting time between polishings while filling voids. 

You will probably never get them all on the first pass.

And many concrete countertop pros are VERY secretive about what they use.

There is no 'correct' way to do things or established rules in concrete tops yet. Many guys have put many many hours into coming up with their own mix design and finding a great sealer and supplier. Not too mention alot of money with the trial and error method.

And it doesnt really matter which quikcrete you use. You dont need a high psi with the countertops... .unless you plan on driving on them.


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## Tscarborough

6 String, have you tried using the maximizer product? It has a nice aggregate and is lightweight to boot.


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## 6stringmason

No I havent. How's the price?


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## parkers5150

*conc. counters*

try googling "cheng concrete counters" he sells books videos actual product and has some rather pricey seminars


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## OneCall

I use a combo of techniques from the california guys. Cheng reccomends using quickrete 5000, I have also used maximizer 5000. More psi the better.

I have more recently started using buddy rhodes. It is an actual white concete and turns out some gorgeous colors. If you want more info on concrete countertops let me know I would be happy to pass along what I have learned through trial and error!

P.S. A crappy palm sander works WAY better as a vibrator than one made for concrete.


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## 6stringmason

OneCall said:


> P.S. A crappy palm sander works WAY better as a vibrator than one made for concrete.


No way. I tried a hand sander and had so many worm holes it was ridiculous. I'll stick with my 14k vpm concrete vibe and keep popping out tops that look like glass right out of the mold.

And why is high PSI better? You're not driving on it. Its a countertop. Concrete will always have a high compression strenght. Its the pulling apart where it gets ya, which is why you need a 'cage' for it.

Regardless, I have used quikcrete from time to time. It does have some very nice fines in it that look great with a dark colored concrete and some grinding.


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## gallerytungsten

*Cheng*

I also recommend the Cheng book on countertops. The book is very detailed and includes ideas on making your own mix. He has another book as well that is also great.

Re: how to make it so slick, it appears it's all about the vibration, troweling, then plenty of grinding!


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## Jay Hood

I too would like to perfect my skills with concrete countertops. The first tops that I made were for my home. I used Sakrete 5000 mix, poured them upside in forms, flipped them. I had a few pin holes, and filled the with a premixed surface concrete. I ginded them with a diamond cup wheel and exposed the aggregate, then polished with wet polisher, looks alot like terrazzo. All in all they turned out nice.

I then tried to help out a friend by installing tops at their house, for a fee.
I used regular Quickrete with a trowel of portland, and well my tops came out like crap. More pinholes than I would care to mention. I filled them with same surface refinisher. I was just going to polish with wet polisher, when I did they started to fall apart. I scrapped 3 tops. 

Lesson learned don't use reg concrete, use the 5000. 

I am going to try my own mix, using the 1,2,3 formula, with counterflo added in. I am going to try to make pure white, as close as you can get with concrete, for my house. Using white portland, white sand, and white aggregate, sounds like it will work.


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## 6stringmason

They started to fall apart??


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## Jay Hood

The edges/corners, I guess from the vibration of my polisher.


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## duburban

6stringmason said:


> 1 part cement 2 parts sand and 3 parts agg.
> The acrylic is a bonding agent and dries up a bit faster than just water slurry, reducing the waiting time between polishings while filling voids.
> 
> You will probably never get them all on the first pass.
> 
> And many concrete countertop pros are VERY secretive about what they use.
> 
> There is no 'correct' way to do things or established rules in concrete tops yet. Many guys have put many many hours into coming up with their own mix design and finding a great sealer and supplier. Not too mention alot of money with the trial and error method.
> 
> And it doesnt really matter which quikcrete you use. You dont need a high psi with the countertops... .unless you plan on driving on them.



6 string... A high psi concrete will help with the sealing process. Guys deep into this business are producing high density pieces that are more resistant to staining and wear without sealers. When I do my counters I shoot for a PSI well above 5k. High slump with low water content is key. Use water reducers for extra workability.

Are you saying you need to Vibe less when using a custom mix vs quickrete? 
I haven't noticed that difference yet.


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