It seals! It just depends on your work.I used it during the COVID summer of 2020 to reseal my bathroom shower tub bottom frame, as it had been leaking way too long. This stuff works great! Only this was my first time doing this since I was probably a kid helping my dad. So, my application worked fine, but I still had small leaks even after I was certain I covered everything around the frame! Although the leaks after the resealing were a significant improvement from before!My issue was that I kept going back and retouching the sealant after 10 seconds or so, which would leave bubbled, wrinkled, and overall a less smooth finish than the first time.I read the instructions, but I couldn’t help it! It’s human nature to want to smooth out something that you feel could be smoother, but this stuff dries quickly! It surprised me. Leave it be and re-do it if you want/need to.The trick really is to "over-apply” and smooth out only once as you go. It depends what you’re doing, and how much surface area you need to cover. I learned from this time I hope. That’s what I will try as I bought another of these tubes. The first tube lasted for the entire bottom frame of the standard shower tub door frame. I had a little left to use to try to fix my previous errors, but the small leaks are still there anyway!Gotta try this one again! Maybe with some exam gloves too, because this stuff is messy by the way, and washing your hands with soap and water only does so much if you are doing a lot at once and using your fingers to smooth. Paper towels help with removal of the slightly dried sealant off of one’s hands.