

Desertcart purchases this item on your behalf and handles shipping, customs, and support to Japan.
🛠️ Seal Smart, Live Leak-Free — The Hybrid Powerhouse for Every Project!
Flex Caulk is a 9 oz hybrid polymer sealant designed for professional-grade waterproofing and weatherproofing. Featuring an adjustable trigger flow nozzle, it delivers precise application without a caulk gun. This paintable, UV and chemical resistant formula bonds to nearly any surface—wet or dry—ensuring durable, crack-free seals indoors and outdoors, from windows and doors to marine and automotive uses.












| ASIN | B0D2F2DCXM |
| Best Sellers Rank | #120 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #1 in Adhesive Caulk |
| Brand | Flex Seal |
| Brand Name | Flex Seal |
| Color | White |
| Customer Reviews | 4.3 out of 5 stars 1,997 Reviews |
| Full Cure Time | 24 hours |
| Global Trade Identification Number | 00810129870756 |
| Included Components | Flex Caulk, White, 9 oz, 1-Pack |
| Item Form | Liquid |
| Item Weight | 255 g |
| Liquid Volume | 9 fluid ounces |
| Manufacturer | Swift Response, LLC |
| Material Type | Hybrid Polymer |
| Model | CFSWHTR675 |
| Number of Items | 1 |
| Number of Packs | 1 |
| Part Number | CFSWHTR675 |
| Surface Recommendation | Window |
| UPC | 810129870756 |
| Unit Count | 9 Fluid Ounces |
| Water Resistance Level | Waterproof |
P**D
Great in tight spaces. Hybrid is not water clean-up.
I certainly have used caulk guns many times, but I was working in a tight space. This made it easy! If your space is even tighter, you might buy the 3-ounce tube, but it is very expensive per ounce. I got the 9-ounce tube of the hybrid polymer. Which is still expensive per ounce compared to standard tubes. But the easy trigger makes it worth the money, especially when working in difficult places. There are advantages and disadvantages between silicone and polymer. For my application, polymer is much superior. But polymer is NOT water cleanup. That is not the product's fault, it is the nature of polymer sealant. You just need to know that. I did use my finger with it, and it isn't easy to get off but that is something I understood. I guess the only complaint I have with the spray can is that you can't tell how much you have left of the product. You just use it until it runs out. But the 9-ounce tube completed my project. One user complained that it was difficult to control the size of the bead even with the adjuster. I didn't have that problem, it came out great for me.
K**S
Beginner friendly
It was very easy to use and it has worked perfectly
B**M
Flex Caulk
Good stuff, really like the trigger control, a little bit of a learning curve to applying to right amount of pressure to the trigger for the amount you what to use.
T**D
Good product; but I won’t buy it again.
Not really sure how to rate this. It’s simple to use, but the one I received had a janky MIN/MAX flow setting…it just kept turning each way so was never sure what the setting was until I pulled the trigger. It came out in a huge glob at first which required a lot of cleanup and wasn’t easy to rectify for a smooth application. Also, there’s not much in each container. Granted, it states 9 oz, but it sure didn’t seem like it. I was trying to fill a VERY narrow gap between the floor & floorboards in a small bathroom and there wasn’t enough to complete the job. At $20 per container, one would expect there to be enough for a small task. I will say, however, that it’s a good product, and perhaps I just got a bad bottle. Despite my problems with it, I’m still giving it 4 stars…but I won’t be buying it again.
A**S
Easy to Use
Really is waterproof. Was so easy to use. It secured a comfort height toilet. No leakage. Fast drying time. Sealed secured in less than 24hrs. Spout makes it easy to spread the product.
L**R
Flex review
Worked great and didn't hurt my hand, thank you
R**.
FlexSeal Promised a Refund - NOPE!
I purchased 2 cans of FlexSeal to touch up a few areas in the kitchen and bath that had begun to erode. What a big mistake I’ve caulked before but I couldn’t find my caulk gun after a recent move. FlexSeal seemed ideal! No caulk gun needed. Based on the commercials and online videos, it seemed simple to use. NOPE! I was contacted by FlexSeal following my initial review. A representative said that I would receive a refund for one of the cans I purchased. After a month, I followed up with a call. Then I made another call and another call. Each time I left a message. To date, I never received a call back or that refund check. Save yourself some aggravation and don’t buy! Please read my original post. FlexSeal does not come out in a nice small bead. Even on the lowest setting, it spews out in a glob. It is sticky and adheres to surfaces almost immediately. You cannot use a caulk tool or your finger in order to get a tight seal because FlexSeal sticks to the tool and you. Here is the good part soap and water is pretty much useless against FlexSeal. You will need acetone or mineral spirits to get it off you and unwanted surfaces! I nearly scrubbed my hands raw trying to get it off me. Ladies, it will also eat away and discolor your nail polish! I made a mess in my kitchen on the backsplash and granite. A simple maintenance job with an inferior product is now costing extra money. I’ve now hired a handyman to tackle the FlexSeal mess and I’m stuck with an extra tube of the stuff. I only used the white tube and cannot return the clear. Amazon will not take it back!! They know this product doesn’t live up to the hype. I should’ve just bought a new caulk gun and regular caulk, and saved myself some money and aggravation.
A**A
I didn’t like it
I didn’t like and I couldn’t control it
D**D
Flex caulk expensive rubbish
I did want to return it as it doesn’t live up to the hype. Caulking mixture goes everywhere and it’s hard to remove to clean it up. I did also buy Flex Paste and when opened it was rock hard. I was able to get a refund on this one. Expensive rubbish
Trustpilot
3 weeks ago
3 days ago