Floor grind in progress

[thomapa1]

After long consideration, I am choosing to grind by hand - if I run into a snag (dead grinder / going thru too many diamond wheels), I'll likely do an Edco rental.
Maybe I'm an idiot - but I have the time and patience to do this by hand and save a few hundred, if all goes well.
Bosch 1773AK - bought on craigslist for $120, Will resell once job is complete
DeWalt DW4774 4 1/2" Diamond Wheel for $60.
DeWalt D28110 4 1/2" grinder for edges. $60. Will keep when done for other jobs
Safety goggles $12
Respirator $15
Dust Deputy $90 keeps my shop vac clean, great device. Will resell once job is compete.

The Bosch unit is a stud! very aggressive, really go light with this. I keep it moving in small circles for best results.
Picture is results after 1 hour of work. I figure that I am 1/5th complete. Diamond wheel looks great. Had to unload dust deputy @5x and the shop vac 1x. Dust is minimal, mostly from when I run over a high/low spot and the dust shoots out vs being sucked into the vac. system.

Picture is after 1 hour of work. Best done on knees (TWSS).

 

[dcs Inc]

Looking good. When I first started out we had 3 7" grinder set ups. Could knock out a bunch of floor with them. Upgraded to stand up stuff and hardly use the hand grinders now. gene

 

[thomapa1]

I'd give my right one for a 7" Bosch grinder with the metal shroud - really a great unit/design - just small...but the price is right.

 

[dcs Inc]

I like the joedue.com dust shrouds. I've had 3 going on 8 years now and still going strong. The 24 segment cup grinder works real well without leaving a lot of curfs marks. The 12 seg is faster but you have to keep it moving. I sell his stuff so yes, I'm a bit partial. I like the fact you can get different grits in the 24 segment cup grinders. You can get the concrete pretty smooth this way without getting into the more expensive diamonds. gene

www.elitecrete.com
www.elitecreteindiana.com
www.indycrete.com
[email protected]

 

[STIBuilder]

I just got qouted 276$ for a walk behind tool with the diamind grinders twin 7" heads

 

[JamieK]

Check your private messages!

 

[thomapa1]

Progress after 1 day - @ 3/4 done
Work is not too bad
Biggest challenge is 'floating' where I get high/low spots based on how the floor was layed or softer concrete areas. Works best if I apply little to no pressure and just guide the grinder. Diamond wheel looks great - will have no issue finishing with one.

started @11am, took a number of breaks (I was still working), ended @5:30 - prolly a total of 4 hours of work. Another 2-3 left including edges

 

[Baada]

Wow....you are so lucky. It took me waaay longer with a combo of a walk behind 10" and the hand held 7" diamond cups. I think my concrete was super hard. It's over 55 years old so I'd say it's cured.

Looking good dude...finish it off.

 

[Edger]

Very lucky your concrete is not too hard, good job, great pics, this is how it should be but seldom is that way.
Concrete not too hard, reasonable diamonds, good dust collection system, well done.

 

[thomapa1]

...and done. took 1.5 hours to do that last section.
Only have edges left....waiting on small grinder to arrive.

 

[On1Wheel]

Question; do you plan to pull your molding before doing the edges?

 

[admranger]

My knees hurt just thinking about doing this...yet here I am facing the thought of taking my old epoxy off after 11 years of abuse.

 

[thomapa1]

Poor planning on my part...I just put the shoe molding up last month - I do not plan to remove it. I'll see how close I can get with the smaller grinder...in the end - it is still just a garage, a few nicks won't kill me.

 

[admranger]

Poor planning on my part...I just put the shoe molding up last month - I do not plan to remove it. I'll see how close I can get with the smaller grinder...in the end - it is still just a garage, a few nicks won't kill me.

Could you hold a long, thin putty knife between the grinder and the moulding? Something to add some protection for it.

 

[thomapa1]

Here is a GoPro video of the Bosch and dust deputy in action in case you may be interested. You can see how fast the grind goes - likely due to soft concrete

http://vimeo.com/37262718

 

[Edger]

Good video, great setup, you cannot get it much lower cost than that and still have it work properly. The shop vac is useless on its own, the separator is a wizard for really good dust separation enabling a low cost vacuum to do the job. Well done.

 

[RKA]

Looks great! Can't wait to see the final result!

 

[LegacyIndustrial]

Great job. That little deputy saves the day!!

 

[dcs Inc]

Those are the kind of projects I dream about. Good for you! Now be careful on how you do your final cleaning before applying your goods. gene

www.elitecrete.com
www.elitecreteindiana.com
www.indycrete.com
[email protected]

 

[marcello7x]

i thought you were nuts doing all that by hand on your knee's. After seeing the video of how easy it cut through thats not bad at all. I wouldn't mind doing the same.

Side note, gopro's is one of the best camera's ever!

 

[Uncle Ben]

Great set up. Thanks for sharing and thanks for the video.

 

[thomapa1]

...and a short video of the edging process. Used a 4 1/2" DeWalt grinder. I was worried that I would tear up the shoe moulding. I used a less aggressive cup wheel and it worked out perfectly. Got right up to the edge, had to hit the corners with a dremel and stone wheel. As you can see dust is significant, imagine grinding without the Bosch type shroud with a dust attachment!

http://vimeo.com/37383788

After the edging, I dumped water in sections and used a stiff broom. Allowed water to pool slightly, then used my wet vac to **** it up. I noticed a number of areas where water was repelling. Looks like car fluid leaks, etc. Instead of grinding more, I used the acid etch for spot treatments. Acid + broom + wait + broom + water + wet vac + water + wet vac. Looks better now. Went over the floor one more time with water, broom, wet vac. Will let it dry now. Have to figure out spall patching, might be ready to prime by Tues/Wed this week.

 

[Edger]

Like a true professional, not recommended to do it without a dust shroud, but at least you were able to capture a good part of the finest dust the way you did it. Congrats again, good video. Also very smart to use the acid combination and check absorption.

 

[Voyager2]

This thread is kinda old but I'll ask anyway.

I have a slab that dropped 1/2 inch on the downhill side of my house (when it was poured in 1978), while the footing remained in place. So the footing sticks out 2 inches from the baseboard, 1/2 inch high. To make the footing and slab match, I can either put self-leveling topping over 2/3 of the floor, OR grind down the exposed footing to the level of the floor.

I'm leaning toward grinding. If I remove the baseboard, this concrete strip is 2 1/2 inches wide, 23 feet long and 1/2 inch high. Any idea which size grinder would be best and how long it would take? Home Depot has several sizes for rent, including a 7 inch Makita. I could probably cut away the bottom 1-2 inches of wall board to allow the grinder further in.

 

[dcs Inc]

Do you have positive drainage? If this has created a low spot where the water collects you may be better to have the slab mud jacked and have it lifted. Just a thought.

 

[Edger]

Grinding will be very slow and 21/2 in would not give you a dust seal so you would have a mountain of dust in the area. It is easy to grind off peaks on a flat slab, but once you begin to attempt some serious depth it is usually slow and hard to make headway. The exception would be if it was softer than normal. I think adding a layer in the low spot would be better, but you need to prepare and you need to know that the product is good and exactly how to use it.

 

[Voyager2]

Thanks for comments.

Well, the water didn't run because the slope is too small, meaning the self leveling underlayment would spread over most of the room. Need to contact an expert installer about this.

A board glued next to the concrete strip would allow the shroud to work, but the concrete is 34 years old.

In one room, ants have excavated an area under the slab (brought the dirt up through the the crack!). Filling the void with urethane (whatever is used now) might support this portion of the slab. Have also thought of inserting 1/2 inch rebar around perimeter, drilling through footing and 5 inches into mid-slab (or a bit lower), about every 2 ft or so.