epoxy floor prep - acid etch, diamond grind or leave as is?

[nomercy346]

Hi guys, I usually just follow some threads around here, now and then, but now me and my dad are about to put epoxy floor coating in his new garage and I hope some of you guys can help us out with a couple of questions...

The garage sits on a new slab, and the concrete has a pretty smooth finish. Now I have spent countless hours on the web reading about floor prep etc.
Some people will tell you all you need is a porous surface (and clean obviously) on the concrete. Others will tell you it has to be rough to some extent as well and you have to acid etch or diamond grind no matter what. (I know that is probably the safest route).

To test for porosity, I splashed some water on the slab and when I wipe it over the surface it instantly darkens and the water disappears. Not wiping it around it just darkens instantly but the water will pool up. No vehicles were driven on it yet, so no oil, tire marks etc.
The surface feels roughly like 4-600 grit sandpaper.

Is that enough to risk it and just clean it up and put the primer on (as I have been told by some people)? Or should we still acid etch or grind it. How rough does the surface need to be to have the epoxy securely binding to the concrete? Reason I ask is I'd rather keep the smooth surface we have. Wouldn't the sanding marks and rough texture still be visible in the coating afterwards?

[dmayer]

Is there a customer service number on the container that the epoxy floor coating is in? Maybe you could contact them and see if they can give you better guidelines to go by. Maybe they could email some 'acceptable' and 'unexceptable' photos or something along those lines. Otherwise I'm not much good to you. Sorry.

[g8ts]

Hey nomercy,

Just my 2 cents,

I've done a few garage floors with epoxy paint on my garage and a couple friends.
These where all old pretty beat up garage floors, specifically mine a lot of oil spots from years of use.

1) We scrub them down with a good cleaner, usually what ever comes with the epoxy kit. If no cleaner with kit a good orange citrus cleaner or purple power cleaner, a good pressure washer always helps get it clean faster, but not necessarily needed.

2) We prime the clean concrete, this i find to be the best practice for older floors. But if i was painting a new floor i personnel would do this.

KILZ® Premium Primer

you have to use the premium, the acrylic resin in the primer in combination with the epoxy paint will give you a superior adhesion. The Kilz primer seals in any deep oil spots. I did mine over 10 years ago I abuse the hell out of that floor and it still holds up great.

But in the end a new clean concrete slap cleaned and blown and broom'd off, will be fine for the epoxy paint adherence. Just get in there and get'r done...good luck. P.S. i don't work for kiltz...

[CarbonCrew]

You would be way better off asking that question over at the GarageJournal forum. They have a sub forum, specifically for garage flooring jobs, filled with tons of info. That forum is here: Flooring - The Garage Journal Board

[nomercy346]

You would be way better off asking that question over at the GarageJournal forum. They have a sub forum, specifically for garage flooring jobs, filled with tons of info. That forum is here: Flooring - The Garage Journal Board

That's what I was figuring, thought I'd try asking it on here, cause I already have the account haha

ok, thx for your replies so far!