Epoxy Prep - Diamond grind or Carbide??

[Allstar]

Hey Guys,

I'm getting ready to put down some epoxy on my garage floor. It's about 650sf and there is a layer of paint on it (which is peeling in many spots).

I keep reading on this forum that diamond grinding is good way to go about prepping the concrete. I just spoke to my local tool rental shop, and they recommend I use a floor polisher with a carbide blade instead of a diamond blade due to the layer of paint that is already there. I've never done this before, so I just want to make sure I'm getting the right advice.

Can anyone confirm if this would be the right way to go about it??

I think this is the polisher in question:








Thanks

 

[tncatadjuster]

I use the carbide cutter method with great results. If the concrete is smooth enough for it to scrape. It must be used with a belt drive buffer though. If not then when you hit something solid it won't break a pin, it just slips.

 

[JD in DFW]

Hit one of the bigger rental centers and ask for a Edco grinder, they come in electric 10" I think and a 24" duel disc gas powered unit. Or call around for guys that do shot blasting, if they are hungry for work they will do that small amount of flooring. A stand up floor machine will take for ever and I would bet you spend more time waiting for the unit to cool down after it trips it's overheat breaker.

Also you might call some of the concrete coating installers in your area and see if they will come out and do the grinding for you. I have done that for some DIY guys that wanted to do their own coating, but did not want to do the prep. For your size garage I would be at about $1.25 sqft in my area to grind it as well as hand grinding and kissing the 90 degree edges. If the DIY ask's for pointers and "how to" questions on the method and process for applying the coating that cost extra!

 

[Allstar]

Thanks for the tips!

I was able to locate an Edco electric grinder. Pretty sure that's the one I'll be going with. I would much rather do it on my own and not pay someone else to do it, not because I'm cheap, but because I take pride in doing things myself. I'm sure many of you can relate...

Thanks again!

 

[AlphaGarage]

If it's just paint, either carbide or diamond will probably do the trick, the rental yard should be able to help you pick the right media (a fresh set of diamonds will probably work better than an old set of carbides and vice versa). Edco's are good - I prefer the dual head ones, they work a bit quicker because they're wider and heavier, that weight is also their downside. But then I'm a lightweight and I need help to get one off the back of the pickup.

 

[kneesee]

I just opened a Sunbelt rental catalog and they list various Edco machines. Which model is the recommended one?

 

[Allstar]

The one that I was recommended is the Edco Electric cement floor grinder model S-EC.

 

[AlphaGarage]

Keep in mind that often times your choice is limited to what the rental yard has in inventory, and as often as not it will be older stock.

Don't let that bother you, we're not talking iPods here, these machines aren't that high tech and one 15 years old will pretty much do the same job as a new one, it may be a bit noisier and dustier, but the end result is what matters.

 

[thegarageguy]

The carbide scrapers will help remove the coating but it will not grind the concrete. You still need to diamond grind after. Vac it up well, run a damp mop to ensure all dust is gone, then epoxy your heart out