concrete floor repair questions

[ghostdog]

Hello everyone,

I've been lurking around the site for a while and have become a full-on GJ junkie! I'm amazed at the talent on the Journal and you all have inspired me to get my garage in order.

I'm looking to acid stain my garage floor and had a couple of questions regarding minor flooring repair:

1. For patching the odd small chip (no more than 1/8" deep) would it be ok to use something like quickcrete bonded topping mix? And will this give me a relatively smooth finish provided I trowel it decently?

2. I have a few random small blobs of residual rough concrete on top of my smoothly finished floor (each blob no bigger than 2" in diameter)that I would like to grind down flush. Would a handheld grinder work? And if so, what type of disk would you suggest?

Thanks for the help.

Chris

 

[chickenhauler]

1 - You can do that, but your acid stain will not be uniform. That area will always look like a patch unless you cover it with an epoxy or paint.

2 - You can use a 7" grinder with a cup grinding wheel to easily take off the bumps. But, just like a patch, if you get down into the aggregate, your stain will not be uniform in those areas.

 

[LegacyIndustrial]

Acid staining rarely looks perfectly consistent, people choose it for the dark and light hues.
At least the masonry repair products will absorb the stain, epoxy products will not.

 

[ghostdog]

Thanks for the advice!
Will one of the big box stores likely carry the grinding cup or disk to grind off those few blobs of concrete? There's probably only about 5 small deposits that I need to grind off, so I'm hoping they're not too expensive.

Thanks again.

 

[Edger]

Ghostdog, almost any diamond disc will do the job, but I suggest you buy or borrow a multispeed grinder and run it at the lowest speed to make it easier to grind flat without digging a ring mark into the floor. Sanders and polishers are good for that.

The coarse diamond grit (20-40) will clean it up faster and also leave scratch marks. An 80 grit diamond wheel will be slower with a finer finish. You may have to go to a diamond polishing supply company for those.

You can contact http://www.huachangdiamondtools.com and they will put you on to a reseller near you.

 

[ghostdog]

Thanks for the replies guys! I lucked out and was able to take off the blobs of concrete with a screwdriver without doing any damage to the floor. It's the small victories! For the second part of my question, will quickrete bonded topping mix be my best bet for patching any small divots in the floor? It looked like it was the most suitable product at the big box store that they sold.

Take care.

 

[chickenhauler]

I personally only use Quickrete branded anything for dumping in a post hole. I recently used a self leveling topping called Flo-Top made by Euclid and it gave me the anticipated results. I still used a cup grinder and surface ground the entire floor first, along with a bonding agent. Still working on some things, but pictures will be in my Bendpak/Racedeck write up.

 

[nateplumb]

Personally for patching small areas I use hydraulic cement. MIX ONLY WHAT YOU NEED. work fast

 

[ghostdog]

Will the hydraulic cement take an acid stain?

Thanks

 

[dcs Inc]

Most hydraulic cements will take stain. the problem is they will take it differently.
Hydraulic cements are made to expand when drying to lock them in place. A thin patch may not be suitable for this. Done a lot of interior staining where they take up carpet and all of the carpet tack strips have blow outs that need to be patched. I use our Thin Finish overlay product to patch them knowing they will take stain differently. I then offer a darker border to "hide" the discoloration.

We have our Hydra Stone Dyes that I use a lot to "faux" in areas that don't take well of just look too goofy. I have found that instead of spending a month of Sundays trying to make a blemish go away, turn it into an accent. I've turned hair line cracks into vines, blow outs into borders and bands, bubbles, leaves, foot prints..... anything that works for your decor and theme to hide the blemishes.

When deciding which patching compound to use, don't use the PVA stuff, (vinyl patch) It's like working with hot bubblegum and with get a polymer lock on the surface and not take color. Go with an acrylic polymer enforced patching compound. Make sure it's cement based and not gypsum based. I'm not a big fan of acrylics but for the diy, it's better than most. You could make your own by mixing silica sand, cement and an acrylic bonding agent. Over fill, let dry and sand.
gene, Elite Crete of Indiana

 

[chickenhauler]

SECTION 3 - PRODUCT COMPOSITION
Chemical Name CAS-No. Weight %
Crystalline Silica (Quartz)/ Silica Sand 14808-60-7 40.0 - 70.0
Calcium Carbonate (Limestone) 1317-65-3 15.0 - 40.0
Portland cement 65997-15-1 15.0 - 40.0
Cement alumina chemicals NJ TSRN# 51721300-5813P 7.0 - 13.0
Calcium salt 7778-18-9 3.0 - 7.0

I just looked at the MDS for what I used. I honestly don't know what the difference between silica sand and regular sand. I assume that the "alumina chemicals" and calcium salt are for flow-ability, and probably along the same lines as water reducers that the redimix plant puts into concrete?

 

[thegarageguy]

no cementitious patching material you use will match your concrete....It can be done but it's an art that most people will not pay for. If you can't live with the blemishes, resurface the whole floor.

 

[ghostdog]

Thanks for all of the input everyone! I understand and am ok with the patch material not matching the rest of the concrete. My biggest concern is finding a durable, easily sourced patch compound that will accept a stain and trowel out smooth.
Gene, can you name a brand of the product you're referring to that I might find locally?

Take care.

Chris

 

[dcs Inc]

Well other than mixing your own or purchasing some of my stuff, I'd suggest speed line fast patch with an acrylic additive. It's either speed line or red line patching compound. You will have to go to a concrete supply house. Kmart... I mean Lowe's or any of the other diy stores don't carry it. Sonoborne makes some good patching compounds also. They have structural and non structural patching compounds. Structural patching is like for a corner of a step. I think there prucduct is called feather patch.

What you are looking for is something that feathers well and non shrinking. The alumina in chickenhaulers post of the product breakdown does that. The calcium salts expedite the dry time. gene Elite Crete Indiana

 

[nateplumb]

Keep in mind you will want a cementous patching material and not a gypsum based.