






🧱 Seal the cracks, not your style—stay flawless, stay flexible!
Bluestar Flexible Concrete Hairline Crack Filler is a precision-engineered, waterproof acrylic and polyurethane formula designed to fill and seal hairline cracks in concrete surfaces. Its micron-sized particles ensure deep penetration, while its flexible composition withstands extreme temperature changes. Easy to apply without special tools, this 8 fl. oz. gray filler dries quickly to a seamless finish, making it ideal for driveways, patios, and sidewalks. Proudly made in the USA, it offers a durable, professional-grade solution for preventing further concrete damage.
| ASIN | B073ZM4TWT |
| Best Sellers Rank | #248,553 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #591 in Wall Surface Repair Products |
| Brand | Blue Star |
| Color | Gray |
| Date First Available | July 17, 2017 |
| Is Discontinued By Manufacturer | No |
| Item Form | Liquid |
| Item Weight | 8 ounces |
| Item dimensions L x W x H | 3 x 3 x 8 inches |
| Item model number | HL90GR-1 |
| Manufacturer | Bluestar |
| Material | Acrylic, Polyurethane |
| Number of Items | 1 |
| Product Dimensions | 3 x 3 x 8 inches |
| Style | Compact |
| Surface Recommendation | Floor |
| UPC | 866019000147 |
| Unit Count | 16.0 Ounce |
| Water Resistance Level | Waterproof |
N**P
Worked as advertised
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.
J**O
Easy to apply, filled in narrow cracks quite 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.
B**L
Good but you need more than you think
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.
C**T
Using both colors helps it better blend with surrounding concrete
I bought the gray color after using the light gray to break up the color. The treated cracks are much less noticeable now.
M**E
M777
Good results, may vary on the size of the cracks, but in my case it worked. Just follow the directions
M**L
Save your money
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.
S**T
Adding and durability
It doesn’t add to old concrete and easy broken
R**E
Bluestar Flexible Concrete Crack Filler
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.
A**R
I used it on old concrete step, filled good but much lighter color, so obvious. On cement walk, white/gray you can't notice
Trustpilot
2 weeks ago
1 week ago