How to prepare concrete floor for epoxy coating?

[an_kv]

To prep the concrete floor of garage for epoxy coating , which is better - Etching with acid or grinding the concrete ?

Wanted help to know which Epoxy primer should I use to prep the concrete floor for Epoxy coating later. My plan was to grind the floor and put a primer ( as was suggested by some you tube videos) and then put the Epoxy coat on top. Planning on getting Dymark Epoxy kit but not sure which primer to use. Some suggested Oncrete EP52 two part primer, but I can find it in Bunnings or any place near to me. Any product equivalent to Oncrete EP52 primer that I can find in Bunnings ? 

Community manager's note: Check out How to apply epoxy to a garage floor for expert advice.

[MitchellMc]

Hi @an_kv,

Both etching and grinding will prep the surface by keying it. Typically, most products require you to etch the surface with an acid. This process is far easier than grinding the whole area. Do you have any bumps or lumps you need to grind from the surface? 

Here are the instructions for the Dymark Epoxy kit. The kit comes complete with your etching agent, and no primer is required. I would be hesitant to recommend any primer, as this product is designed to cover the concrete itself, not a primer. Any primer you add will probably diminish the paint's ability to adhere.

Also, check out this helpful step-by-step guide on How to apply epoxy to a garage floor from one of our talented members @prettyliving. 

Please let me know if you have further questions.

Mitchell

[an_kv]

Thanks @MitchellMc  .. it’s a fairly new garage floor, no bumps. So will go ahead with acid etching then. Couple of cracks are there, any suggestions on how to fill them. 

[MitchellMc]

I'd recommend Timbermate Concremate for the cracks @an_kv. 

Push it as deep as you can into the cracks and finish flush with the slab's surface. Clean up any residual filler before it dries. If once dried, the filled area is slightly proud of the surrounding surface, you can knock it down with some sandpaper or a concrete rubbing stone. Once you've sanded the area, run your finger over it. If you can feel the repair, you need to do more sanding. Your repair needs to be a perfectly smooth area once finished, or you'll see it through the topcoat. 

Mitchell

[an_kv]

Thank @MitchellMc  great help.

[an_kv]

@MitchellMc  Any recommendation on the polyurethane top coat over epoxy ? 

[MitchellMc]

Hi @an_kv,

You can apply Rust-Oleum Clear Gloss EpoxyShield Premium Concrete And Garage Coating over your epoxy paint to provide protection. It needs to be applied within two days of you painting the floor. If it's after two days, you'll need to sand the floor lightly with 120grit sandpaper.

Mitchell

[an_kv]

Thanks @MitchellMc