What kind of abrasive for smoothing concrete

[VictorL]

I've tried to strip off paint from my garage concrete floor with RAS-115 and Saphir 24 & 36. No luck. Just small scratches on the paint.  I have very nice Bosch grinder with diamond wheel, but I'm afraid that I'll fight dust afterward for couple years. I stripped exterior paint with this beast last summer from my house foundation 50' x 24' x 2-4' (15m x 7m x 1m) Just a couple hours of very dusty job, but garden hose resolved all dust related problems.

Craig,
What's the name of that red tool with dust collection port?

 

[AlexThePalex]

Alex, thanks for posting your results there. I didn't think that the sander would do the job. Charimon has the right idea and kind of tool for the job. Will you post when you ultimately get the job done and indicate what you ended up using?

Rey, I didn't need to do any job with concrete. It's Chuck, the original poster of this thread who asked for advice. Some people told him the Rotex with Saphir could do it but I doubted it and advised Chuck to use a concrete grinder like the one Craig/Charimon posted a picture of.

But then some people said it was possible with the Rotex, so I just thought let's try it out since I was working on a concrete shed anyway. But I only need to paint the woodwork. Not the concrete itself. It was just an experiment.

I hope that when Chuck finishes his job he posts back to us how it worked for him and how he did it.

 

[johnsonri]

Rey, I didn't need to do any job with concrete....It was just an experiment...

Alex, I was confused. I thought that you traveled from the Netherlands to Chuck's place there in Palos Park, Illinois to help him out  [big grin]

Rey

 

[Chuck Kiser]

OK guys it was a success, but not with the Rotax. I did not have a chance to use it with the new Saphir dics that Bob Marino overnighted to me. Sorry Bob. When I got the job site on Thursday my partner had already done the job with a baby Porter Cable belt sander with 60 grit.

Just for the record, we did grind down concrete seams that had been filled the day before with a concrete patch product. Although dry to the touch it was not fully cured. This make grinding and leveling much easier. It was the patch that was leveled to the concrete floor height.

And Alex, anytime you want to come over and help out, just ask [big grin]. I enjoyed my time at the University of Eindhoven. I worked for a Dutch company that was based there. The owner was a professor at the University. Nice country and great people.

 

[TheToolPlace]

Depending on the exact type of work and how much work you are planning on doing there are several options for grinding concrete smooth.

One of the best performing although most expensive option is a stand alone concrete planer.  The one we stock is made by Makita and performs very well.  

Another more reasonable option is to add a Diamond Cup Wheel to an ordinary angle grinder.

Thanks,

Chad

EDIT.  Quick post by Chuck.  Glad to hear it all worked out for you!

 

[richard.selwyn]

I guess I'm too late to the party, but what you needed (of course) was a Festool concrete grinder.  I have one - it works exactly like the one shown earlier in the thread, but I think it is now sold under the Protool brand.  You NA guys need to get lobbying again.

http://wwwinet.my-tts.com/Protool/Produktbilder/07_sanieren/jpg_zoom/zoom_07_rgp8011e_778405_p_01a.jpg

Not sure if the link works, but this is what I have except under the Festool brand.

Strange that they moved it over to Protool.  They still sell other odd stuff here under the Festool brand like a carpet scraper and a mixer.....

 

[AlexThePalex]

I guess I'm too late to the party, but what you needed (of course) was a Festool concrete grinder.  I have one - it works exactly like the one shown earlier in the thread, but I think it is now sold under the Protool brand. 

Too late for the party but you just beat me to it. I just remembered Festool made a concrete grinder, the Festool SAF 750E.

I was just Googling around to find some pics and when I found them and return here I see Richard mentions it. I is discontinued now under the Festool name and moved over to the Protool brand under the name RGP 80-8 E

But here are some pics I found for those who are curious.

And the Protool RGP 80-8 E

Strange that they moved it over to Protool.  They still sell other odd stuff here under the Festool brand like a carpet scraper and a mixer.....

Yeah, I find it strange too. But somehow the marketing geniuses decided it should be like this. I sincerely don't understand that strategy though. I don't think a brand should necessarily cater to one specific sector but could very well cater to many sectors. Other pro brands got no problem with it.
 

 

[AlexThePalex]

Alex, I was confused. I thought that you traveled from the Netherlands to Chuck's place there in Palos Park, Illinois to help him out  [big grin]

I'm fast, I'm flexible, but this was too big a stretch even for me  [wink]

When I got the job site on Thursday my partner had already done the job with a baby Porter Cable belt sander with 60 grit.

If a baby PC with 60 grit can do it, the Rotex should do just as good.

Just for the record, we did grind down concrete seams that had been filled the day before with a concrete patch product. Although dry to the touch it was not fully cured. This make grinding and leveling much easier. It was the patch that was leveled to the concrete floor height.

That explains it.

And Alex, anytime you want to come over and help out, just ask [big grin]. I enjoyed my time at the University of Eindhoven. I worked for a Dutch company that was based there. The owner was a professor at the University. Nice country and great people.

Sure, I'll come and help out, no problem. As soon as I got my own F16. Got to be home for dinner again, or the missus will complain, you understand.

 

[Bob Marino]

I just did a quick experiment because I wanted to check this out again.
My basement's floor (the part that  I sanded was cement) and that Saphir worked well, but wanted to try it on the sidewalk outside my house. This is the "old stuff" concrete, filled with a lot of aggregate; the way sidewalks used to be made.
Anyhow, with Saphir 24 grit, RO 150 in Rotary mode, I sanded just to see what would happen. I only sanded for a very short time, and there were no seams to level but the small test area sanded was waaaaaaaaay smoother than the nonsanded area. Even the small rocks/aggregate was smoother. I wouldn't want to sand huge areas of the stuff and as noted here, there are other machines/tools much better for the task, but for Chuck's limited application, it would have worked.

Bob

 

[score0matic]

Craig,
What's the name of that red tool with dust collection port?

Victor That is an Hilti DCG 500 S it is a small frame grinder with 12 amps  i believe the European designation is the DCG 125s

  This grinder sells for $250 and the hood for
$125  The hood is a quick detach bringing it back to a regular grinder.  $375 is less than the Flex or the Bosch dedicated grinders.  Craig

 

[TheToolPlace]

I guess I'm too late to the party, but what you needed (of course) was a Festool concrete grinder.  I have one - it works exactly like the one shown earlier in the thread, but I think it is now sold under the Protool brand. 

Too late for the party but you just beat me to it. I just remembered Festool made a concrete grinder, the Festool SAF 750E.

I was just Googling around to find some pics and when I found them and return here I see Richard mentions it. I is discontinued now under the Festool name and moved over to the Protool brand under the name RGP 80-8 E

But here are some pics I found for those who are curious.

And the Protool RGP 80-8 E

Strange that they moved it over to Protool.  They still sell other odd stuff here under the Festool brand like a carpet scraper and a mixer.....

Yeah, I find it strange too. But somehow the marketing geniuses decided it should be like this. I sincerely don't understand that strategy though. I don't think a brand should necessarily cater to one specific sector but could very well cater to many sectors. Other pro brands got no problem with it.
 

Wow, that's a nice looking grinder.  With proper dust collection!

Chad

 

[score0matic]

The Festool/Protool scarifier is just a Flex re-badged

  a Flex 1506 with out scarifier head
Craig

 

[AlexThePalex]

The Festool/Protool scarifier is just a Flex re-badged

Craig, you're right. There's a few details different, like the switch that moved from top to side, but overall, you can see it is the same machine. I had a feeling Festool might not have designed this thing themselves, it's so out of touch with the rest of their program.

Btw, what's a scarifier head?

 

[score0matic]

in the pic, see the little star wheels,  there are four sets of three, as they roll they impact the surface fracturing any coatings and cleaning off any concrete that wasn't completely bonded

they are also good for taking off a controlled amount of material  the Flex unit has a guide rail so you can take off and re-apply safety nosing on concrete and stone steps
Craig