# Forum Home Renovation Concreting  Rounding off a concrete edge

## Rossluck

We have a slab next to our house that we want to slice in half. Does anyone know of any way to "round off" the edge of newly cut concrete so that it is similar to edge-trowelled concrete? 
A strange question, I know, but outside of a grinder with a masonry disc, I can't think of a way of doing it.

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## Honorary Bloke

> We have a slab next to our house that we want to slice in half. Does anyone know of any way to "round off" the edge of newly cut concrete so that it is similar to edge-trowelled concrete? 
> A strange question, I know, but outside of a grinder with a masonry disc, I can't think of a way of doing it.

  Grinder with a masonry disc.  :Frown:   :Biggrin:

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## johnc

An old coarse oilstone will do it, but it would be slow going and knacker the stone if not careful.

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## Bleedin Thumb

You can get grinding stones (known as rubbing stones) - basically how Johnc describes but you won't knacker the stone. I would still use a ginder wheel to put a 45 deg bevel on it first them use your rubbing stone to round it off.

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## bricks

you could break the corner at 45 degrees, then repair it with a concrete epoxy ( something like megapoxy). If you add a small amount of the dust from the origional concrete it comes up fairly close to the origional colour.

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## Amb

Hi Rossluck A friend of mine once gave me some concrete grinding stones he uses at work all the time. One is coarse grade, the other is fine grade. They use them to take off any sharp edges after removing the form work. I believe they are the stones that are used on terrazzo grinding machines. Any way, you can 'sand' down concrete with these stones by hand, just as easily as sanding down a piece of wood with sandpaper. I'm not exaggerating, so taking off a bit of a corner would be very easy. They work just as well on fully cured and old concrete, and the aggregate stone is also no problem.

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## Rossluck

> Hi Rossluck A friend of mine once gave me some concrete grinding stones he uses at work all the time. One is coarse grade, the other is fine grade. They use them to take off any sharp edges after removing the form work. I believe they are the stones that are used on terrazzo grinding machines. Any way, you can 'sand' down concrete with these stones by hand, just as easily as sanding down a piece of wood with sandpaper. I'm not exaggerating, so taking off a bit of a corner would be very easy. They work just as well on fully cured and old concrete, and the aggregate stone is also no problem.

  
Thanks Amb, and everyone else. Great advice as usual.  :Biggrin:   :Biggrin:   :Biggrin:

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## Terrian

> We have a slab next to our house that we want to slice in half. Does anyone know of any way to "round off" the edge of newly cut concrete so that it is similar to edge-trowelled concrete? 
> A strange question, I know, but outside of a grinder with a masonry disc, I can't think of a way of doing it.

  
grinder with a diamond disk to start with, then the masonry disk (100mm grinder ?)

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