So I am working on getting my concrete porch stripped down and am planning on going with the Quikrete 1 part epoxy floor sealer 1-Part Epoxy Garage Floor Sealer | QUIKRETEŽ Coatings . I have pressure washed the floor with my pressure washer with a turbo nozzle and it has removed the majority of the old paint, except in areas where it must have been adhered better. I was thinking about renting one of the ezV floor sanders from lowes and using the 36 grit sandpaper to remove the rest. RustOleum.com Here is the link to the info on the sander, it is for wood, but I was thinking it will do the same thing. Anybody else tried this? I want to get it to the bare concrete so I can apply the bond lok concrete cleaner before the 1 part epoxy.

 

If you used an electric pressure washer, rent a gas driven machine instead, 2,000 psi or higher. Make sure that they give you a red tip with it.

Then don't seal it anymore. Let it breathe.

 

It is a gas pressure washer 2,500 psi, and letting it breathe is not an option, don't like the look. Already used pressure washer and stripper, sanding or grinding is the only option. Want to know if anyone has tried the floor sander before.

 

I never sanded concrete. Try it if you think it will work.

 

Does this porch have a roof?

I'd be leery of applying any full paint coating to the slab. Usually a porch slab doesn't have a vapor barrier under the concrete. The lack of vapor barrier lets moisture seep thru the slab under the paint causing it to peel I prefer to use a concrete stain - they're less prone to peeling

You have several choices where the existing paint is still adhered. You can let it set awhile as Pulpo suggested and then scrape and pressure wash again in a week or so or you can use some paint and varnish remover on those areas [PW again when done] it is also acceptable to paint over the painted areas although that may leave a ridge at the edges of the paint - it may or may not be feasible to sand the transition.

 

An epoxy garage floor paint will be extremely slippery when wet. If your porch has stairs leading down to a sidewalk, it could be very dangerous. Take into account guests or deliverymen who may take a dive trying to access your front door...then think about upping your homeowner's insurance.
There are better alternatives, but most of them are not going to be a do-it-yourself project. Sorry.
But as to your question, yes I have used a floor sander on concrete to prep it for acid staining. It worked fine.

 

This stuff is classified as a stain, and is recommended for patios as well as sidewalks and garages, but has a color to it. See the link to quikrete link in my first post. Here is another that show what it is recommended for, it is the 1 part epoxy concrete sealer. I think I am going to try the floor sander and see how that does, I just don't want to spend the $40 for the day if it is not going to work.

Also, the porch does have a roof. It is screened in.