Diamond Grinder vs Stone Grinder - and what grit

[J-R0d]

Need to grind my floor to install epoxy coating on it. It is a 2500 sq ft slab (50x50). The slab has a power trowel finish on it currently that I need to rough up to install epoxy over The slab has no stains, no oil, etc... just clean concrete that needs to be roughed up.

Checking with United Rental (locally) I can get an Electric Edco diamond grinder with an 11" cutting path, or a gas Edco dual head with stones that cuts 22". The stones come in 10, 24, 80, 120 grit.

If I go diamond what grit diamond would be recommended?

If I go stones what grit stone would be recommended?

How many sets of stones or diamonds would you expect to need on a 2500 sq ft surface.

 

[LegacyIndustrial]

Stones will get clogged and/or glazed in minutes.
Go with the diamonds!

 

[J-R0d]

Any recommendation on the diamond grit then?

 

[LegacyIndustrial]

30/40

 

[CamarosRus]

How much to buy the diamonds pads ???

 

[Prepman]

Diamond pads are in the $35 dollar range if you buy them on line. Use the ll" Edco. The stones do an inferior job and take to long to open up the concrete. Move it from side to side and pull or push at a consisten speed. You will make ridges if you move it to slow or stop moving before turning the grinder off. It has a dust shield and can be used with a vacuum to keep the dust down. A large Ridgid with a bag added along with a cartrige filter will work. Check the bag and exchange for another when full. The 30/40 segments are perfect for coatings. Be sure you vacuum the dust out of the pores or wash before coating.
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