[Master Brian]

Trying to clean up the concrete floor in our 100yr old house. There's pits and such that I'm trying to fill and patch. Trying to find the best way to then grind these patches to get the repairs to be smoother. The plan is to paint the floor. Not looking for perfection, but don't want 1-2" pits and/or the ridge from a patch.

I'm seen concrete grinding wheels for angle grinders, just confused on what to buy. Box store had something for the 4-1/2"angle grinder for like $60. I was just checking Amazon and found some for $10, that sound good.... guessing different functions?!

Can anyone guide me? Room is about 15x30 and only working with the imperfections. I can't recall the exact material being used, but is a quicrete product recommended by one of their reps.

https://www.amazon.com/dp/B07SJ3XVCR/ref=cm_sw_r_cp_apa_i_mgc8EbE0J89EB

 

[Windows on Wash]

For 450 sq/ft? You are getting ready to make a mess or pretty epic proportions. I would bite the bullet and rent a floor grinder with vacuum attachment.

 

[Colbyt]

The Amazon one is probably okay. It would be fine for a very few small bumps.



Like WOW I can't really recommend it. For a bunch of reasons:
the mess, control, burning up the angle grinder, not enough surface area to really smooth it out, all that bending over with the dust flying in your eyes versus standing upright.



I rented a small (12" grinder) unit and that is about the minimum area to really smooth a surface. Even at 12" you have aggressively keep it moving.

 

[Master Brian]

Well for $10, I might have to try it. I'm not planning on working it all in a day or two, just as I find spots I want to address as I'm working on room trying to finish my built in cabinetry and such. I also asked on Amazon and people say it works good.

I know it won't be perfect, but I used one that was similar in a 6" grinder and was fairly happy. End of day maybe I'll end up renting a walk behind unit, but worried those will make HUGE mess. My logic, maybe it's wrong, is that I can patch a small area then knock it smoothish and move on to the next. We're talking most patches are going to be 1-2" pits in floor. I'm not grinding the entire 450sq ft.

 

[Bud9051]

Some will scream at me, but I use a 6" grinding cup on my 4" grinder with no shield. Amazing how easily it floats over the surface and IMO, risk is zero with basic care. Even if it tags you, it is not a cutting blade.

BUT, I agree with Windows and Colbyt, a bigger unit would be better.

I used my grinder to smooth my foundation walls and the dust was so bad I had to fabricate a hood connected to my vac and then had to tape over the air intake vents on the grinder. I could only work for a minute or so and than take a break to let the grinder cool. It did a good job, but I stopped at half way, just too slow and still too much dust. Even my shop vac didn't like it and required a filter cleaning frequently.

Definitely talk to your rental shop, a few bucks and they get to clean up their machine.

Bud

 

[HotRodx10]

I ground down some high spots in a small room using a 7" diamond grinding cup on my 9", 1/2HP grinder. It worked well, except for the huge amount of dust. I put up plastic sheeting and put a couple window fans in set to exhaust, but I could still only work for about a minute before I could no longer see what I was grinding.

If I had it to do over, I would have tried having a helper mist the work area with a hose sprayer while I was grinding, to try to keep the dust down. Bud's hood idea sounds good, too.

 

[Colbyt]

Well for $10, I might have to try it. I'm not planning on working it all in a day or two, just as I find spots I want to address as I'm working on room trying to finish my built in cabinetry and such. I also asked on Amazon and people say it works good.

.

It will work. But if you are needing to grind what you filled you may want to work on you technique a bit.


I have no clue what you are using but a masonry base floor leveler from flooring supply store works better and smoothed out better than anything sold at Orange or Blue.


Specifically I would suggest: Vitex Para-Patch Plus Multi-Purpose Patch & Skim Coat

 

[Bud9051]

Concrete dust is not something to take casually. If I do more I will be buying a respirator with eye protection. I was stupid in my younger years and remember coughing up that dust for weeks after. I fear I never coughed it all out but nothing I can do now, 40 tears later. Fortunately I'm still alive but my exposure was really limited.

Bud

 

[Master Brian]

I will agree that dust is horrible. I have and would wear a respirator for that, I even have a few of the coveted N95 Masks hanging around from other projects. I might just have to rethink the other patches and either stay on top of the patch with a wet sponge to minimize having to use mechanical means to clean it up or look at some of type of patching material, like epoxy that can be sanded easier....

Originally, the plan was to rent a big floor sander/polisher to do the entire area and resurface it for stain as there is parts that are painted or sealed and that was my original desire. Since most of the area will be covered with area rugs, I'm finally thinking paint is more forgiving and can hide lots of imperfections, so that is now my goal. I'll kind of marble it and then urethane over to give it a really nice finish.

Thanks for the guidance and to bring the concerns up....sometimes it helps to have that 2nd set of eyes!

 

[raymondburke]

The Amazon one is probably okay. It would be fine for a very few small bumps.



Like WOW I can't really recommend it. For a bunch of reasons:
the mess, control, burning up the angle grinder, not enough surface area to really smooth it out, all that bending over with the dust flying in your eyes versus standing upright.



I rented a small (12" grinder) unit and that is about the minimum area to really smooth a surface. Even at 12" you have aggressively keep it moving. concrete grinder Los Angeles

Hi Guys,
I am starting to restore a newly acquired 95 XJ , I will be getting the replacement pans from Sherman, just wantedto know if the pan can be easily cut with the grinder, to those who have done it, is it easily doable? this will be the first time when i will be doing something like this.

Thanks,

 

[HotRodx10]

Hi Guys,
I am starting to restore a newly acquired 95 XJ , I will be getting the replacement pans from Sherman, just wantedto know if the pan can be easily cut with the grinder, to those who have done it, is it easily doable? this will be the first time when i will be doing something like this.

Thanks,

I assume you're working on an 1995 Toyota FJ Cruiser. This thread is a year old and about concrete grinding. You'll get more informative responses by starting a thread in the automotive repair or tools subforum.

 

[Jeekinz]

I did a prstty large master bath with a $18 Harbor Freight grinder along with their cup wheel. The wheel is a beast

 

[rafaelrobertson]

The Amazon one is probably okay. It would be fine for a very few small bumps.



Like WOW I can't really recommend it. For a bunch of reasons:
the mess, control, burning up the angle grinder, not enough surface area to really smooth it out, all that bending over with the dust flying in your eyes versus standing upright.



I rented a small (12" grinder) unit and that is about the minimum area to really smooth a surface concrete staining cape coral. Even at 12" you have aggressively keep it moving.

Hi I need to grind down a small patch of concrete floor, but cant fit the angle grinder in there. Is there any other way to do it? Theres a few inches each way, and maybe 5mm to be taken off at most. Its behind the bog, and I need it properly flat if poss.

 

[Colbyt]

What's a bog? 5mm is quite a bit.

Very slow process but you can use a diamond grit multi-function saw blade and tool. There probably are some diamond burrs to fit a Dremel style tool which could be used with or without a ringt angle adapter.

 

[Matt1963]

A diamond cup wheel for a grinder will be way to aggressive to sand down patching compound. If installed correctly it should need any sanding at all.

 

[rogerius]

I just fix our ugly porch by grinding almost 250sqft of concrete. There are couple pictures in my post on this forum. Without proper tools and a vacuum I can't see how to survive from the dust generated. I purchased a good diamond disk and a vacuum adaptor for a 7in grinder and in a few weekend I did it. It's quite a slow process but not impossible.