Best Tool to "Sand" Concrete Down?

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Forum topic by wilschroter posted 07-22-2019 10:32 PM 1395 views 0 times favorited 17 replies Add to Favorites Watch
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164 posts in 1535 days

07-22-2019 10:32 PM

I’ve got some concrete pads that had some stucco posts attached to them. I need to sand down the caulk off the concrete that was surrounding the stucco posts.

What’s the best way to attack this? Since it’s concrete (though I’m focused on the caulk) I’m afraid sandpaper will rip apart immediately the moment it comes in contact with the concrete.

I’ve got a fair amount of it to tackle, so a hand tool isn’t an option.

17 replies so far

View bandit571's profile (online now)


27853 posts in 3694 days

#1 posted 07-22-2019 10:36 PM

Angle grinder….cone diamond wheel…

-- A Planer? I'M the planer, this is what I use

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4155 posts in 2505 days

#2 posted 07-22-2019 11:08 PM

Rent a concrete grinder. HD and lots of folks rent them.

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

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2369 posts in 1986 days

#3 posted 07-23-2019 12:44 AM

like Bandit said one of these on a grinder. They make fast work out of grinding down concrete.

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3442 posts in 916 days

#4 posted 07-23-2019 01:17 AM

What do you mean by “Fair amount”. You mentioned just around some posts. That will determine if i would recommend angle grinder or renting the big machine. Btw, make sure to keep it wet to keep the dust down or it will make more dust than you can believe.

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3859 posts in 2972 days

#5 posted 07-23-2019 01:52 AM

Your title says you want to sand down concrete, but the description says it’s the caulk you want to get removed. What kind of caulk and again how much will matter here. I’d think you’d want to scrape off the caulk first or it will gum up any grinding wheel you use. Though maybe not if you’re willing to dig enough into the concrete.

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3128 posts in 3035 days

#6 posted 07-23-2019 10:24 PM

If you’re just removing caulk, I don’t see why you would need diamonds. HF has a grinding disk imbedded with carbide chunks. $10.

You might also try heating the caulk with a torch or heat gun and scraping it off.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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378 posts in 1371 days

#7 posted 07-24-2019 01:48 AM

Heavy duty sanding disks for your 4 1/2” grinder will do the trick. You need a rubber pad. The HF stuff would work fine, and buy a grinder and the pad while you are there or at HD. It’s mandatory equipment for any DIY’er. With a different disk, you can grind the concrete, or cut metal, etc….

Also a torch and scraper should work fine too.

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1225 posts in 3828 days

#8 posted 07-24-2019 12:39 PM

Like others said, if it’s not much concrete, a cheap masonry wheel in an angle grinder will work. Be aware that concrete dust contains silica, which is really, really bad for the lungs ( Wear a mask.

-- Jeremy, in the Acadian forests

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347 posts in 1541 days

#9 posted 07-24-2019 01:08 PM

I would use a rub block to get the bulk off so you aren’t loading up a wheel. Something like this.

Once the big stuff is off you can clean up with a grinder and work pretty fast.

View wingless's profile


80 posts in 753 days

#10 posted 07-25-2019 11:36 PM

My 4,000 psi / 3.5 gpm pressure washer would remove this using the rotating turbo nozzle w/ little effort.

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Steve Peterson

424 posts in 4093 days

#11 posted 07-26-2019 03:11 PM

If you re just removing caulk, I don t see why you would need diamonds. HF has a grinding disk imbedded with carbide chunks. $10.

You might also try heating the caulk with a torch or heat gun and scraping it off.

- runswithscissors

Be careful not to heat the concrete too much with the torch. Chunks could explode if there is embedded moisture.

I suggest a guy named runwithscissors should try it first. :)

-- Steve

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Myles Standridge

115 posts in 3953 days

#12 posted 07-26-2019 04:38 PM

If you decide to go with an angle grinder/cup type grinding wheel and you’re indoors you should consider one of these shrouds. They’re a pain with the vac hose and visibility in infringed so it’s a bit more difficult to keep it flat and not gouge the concrete but the dust is KILLER!

They also have a 7 inch version which I think would be a bit easier to keep flat on the floor.

View Bill1974's profile


166 posts in 3996 days

#13 posted 07-30-2019 05:30 PM

look at

I have used the this ( to remove thinset, mastic and paint from concrete and it worked pretty well. You will want to have some dust collection on the angle grinder and wear a respirator too.

I tried concrete polishing and grinding discs but they did not work well to just get off what was on the concrete, they either did very little or dug in to much.

these do work best on smooth hard concrete, if the concrete is rough or soft, it will dig in if you are not careful. Also a variable speed angle grinder seemed to work best at slower speeds and the blades lasted longer too.

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520 posts in 2931 days

#14 posted 02-15-2020 02:36 PM

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6647 posts in 2398 days

#15 posted 02-15-2020 03:06 PM

If it is just the caulk you want removed and no actual concrete, I would scrape most of it of first then try a stiff wire wheel followed by some coarse sandpaper to get what’s left. There are also some caulk removers that dissolve the caulk that could be worth a try making it easier to scrape off (I’ve never tried them myself). I would not resort to the diamond or other masonry wheels with an angle grinder unless that doesn’t work.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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