Bluestar FLEXIBLE Hairline Crack Filler, Gray, 16 fl. oz. – DIY Concrete Repair for Driveways and Patios

Had looked around at multiple different crack filler products for some hairline cracks in my garage floor. The cracks are near the door opening and frequently get wet and have been slowly expanding over the past few years when the moisture gets in them. I eventually settled on this product as it seemed to be the most relevant to my issue and was reasonably priced. The application process was pretty slick, the product is fairly thin and easily worked its way into the hairline cracks in the garage floor. Clean up was quick and easy and the product was easy to work with throughout the process. It dries/sets-up fairly quickly and the color matched my standard smooth finish concrete floor well. 24 hours after application it looks very nice and seems to have filled in the hairline cracks and sealed the surface. Once it gets a little garage dirt on it, it probably won't even be noticeable. Now just have to wait and see how it holds up over the winter months with the melting snow and wet floors and temperature changes; but it certainly appears to have filled the cracks and seems like it is sealed up pretty well.

This was easy to use and easily filled in some fine pavement cracks I had. It pours easily, not as runny as water, but more like cream. So far, I'm pleased.

I used it on hairline cracks on a fairly level concrete patio/porch. Pros: 1) It was very easy to apply. It flowed well, didn't hurt my hand like a caulk gun does, and didn't clog the bottle. I felt like I was able to use the entire contents without leaving a lot stuck inside the bottle. 2) It creates a flexible seal. Flexibility is important if you have a clay foundation so that continued swelling or shrinking of the ground won't cause things to crack again as quickly. Cons: 1) Know that the color probably will not match, so the floor will look worse with all cracks in a different color on the surface, but they will be sealed. Product is supposed to be paintable, so painting is an option, but I haven't tried it yet. 2) You need multiple applications and will use more than you think. If I use this again, I will attempt to do multiple applications over several days. After the first application, I thought it was all good, but by the next day the product had seeped down far enough even into the hairline cracks that the cracks were not full. I had to go over the cracks again and a third time the day after that. My advice is to get more than you need and don't assume the project is finished until several days later. 3) It's pretty expensive. I know this is for hairline cracks only, but I had hoped that a small bottle would go farther than it did. Overall: I'd still use it but will try to have more realistic expectations. I don't know how it compares to other self-leveling products, but the ease of application was good. Time will tell if the quality of seal is good, too.

Easy to fill cracks

Good results, may vary on the size of the cracks, but in my case it worked. Just follow the directions

Purchased 2 of these. Just used them in garage floor that we are turning into a gym. Very disappointed it does not fill the cracks it’s like it literally disappeared and I mean cracks were not very deep at all. Save your money.

It doesn’t add to old concrete and easy broken

Easy to use directly out of the bottle with only a little shaking to mix. The nozzle allowed me to apply the crack filler directly into a 1/4 inch crack in a concrete slab. Any overage was easy to smooth out with a trowel, (or in my case, a wet finger). I let it dry overnight but I think it would have been ready sooner. Dries solid, but still has flexibility to move with expansion. The application was done about 3 weeks ago and it is still looks like I just did it. Highly recommend.

I bought this product to fill hairline cracks in concrete, because the bottle says "fine crack filler for hairline cracks" and "micron sized to fill small cracks". Don't believe everything you read, because this product is too viscous to penetrate more than a small superficial depth into small hairline cracks. When I attempt to level it with a putty knife, as per the directions on the bottle, much of the product was pulled out of the crack, showing it had penetrated less than a mm into the crack. It's rubbery like the gap sealers you buy and use in caulk guns, no more effective and much more expensive. Not just a waste of time and money, I'll probably have to try to dig it out and try something else, like a cement slurry, which I probably should have done in to first place. Not happy

I used it on old concrete step, filled good but much lighter color, so obvious. On cement walk, white/gray you can't notice