SIKASikaflex Construction Sealant - White, All-Purpose Polyurethane for Joints 1/2" or Smaller - 10.1 fl. oz - Weatherproof, High Elasticity, Paintable, Strong Adhesion

In my experience with caulk products over many years nothing compares. My regret is that I didn't find it sooner. I was happy to find silicone after watching cheap contractor caulk used in building our new home dry, shrivel, and crack before the home was a year old. And virtually no flex if there is any movement. 100% Silicone has it's merits, if you're satisfied with its color, because its non-paintable. It's also very hard to clean-up and remove now or later, and can be difficult to work with as it can get messy and you have just a few minutes to work it. And even after it dries, it attracts dust and whatever's in the air, regardless of whether it's clear silicone or colored. And it's not cheap. However. it does the job, holds up against the elements for years, works well if you don't want to paint, and it flexes. But the other issues just mentioned sent me on a journey of research and it paid off. Sika has a number of great sealants formulated for various needs. I generally use the PRO Select Construction Sealant around the house. I've also used the product designed for mortar. Some products are "no-sag" and others are self-leveling. It goes on smooth, is easier to work with, is less messy, has a longer working time, and easier to clean up than silicone. If you make a mistake or touch another surface with it you can often remove it with a damp rag. If sitting a while, citric orange solvent generally takes care of it. It also readily takes paint, which is recommended outdoors if you want it to last. Without paint, it doesn't hold up quite as well to UV and the elements as silicone, although much better compared to cheap caulk. This stuff also flexes, reducing the chance of separation in the event there's surface movement. It also doesn't dry up or degrade in the tube as fast as silicone. Another thing I learned recently. I came across a couple tubes 2 years past their expiration date and the product in both tubes performed like new.It's not cheap and some folks complain there's less in a standard tube than other caulks. But this is minor stuff if you want the best sealant for all the reasons I just covered.

I have done a lot of caulking in my life... Like tens of thousands of feet. All I needed was some nice stretchy elastomeric white sealant to go around the inside of my aluminum window to drywall edge cap in my kitchen. I needed something paintable. This polyurethane sealant from Sika was just the thing. The local hardware stores don't have it and I am too far away from Smalleys/Beacon in western USA to pick up and I didn't want to spend money on gas to drive 2 hours to one. So I ordered this from Amazon and it showed up in a couple of days, Prime shipping from Las Vegas warehouse. The job was simple. Back the joint, blue tape the the black aluminum window frame, shoot it and tool it. Pull the tape and let it cure. As soon as it was cured I top coated it with the wall paint and it's been awesome for a year so far.

I bought this by mistake. I meant to get the self leveling sealant. This stuff is gooey and not self leveling, but it’s OK. It’s intended for use on vertical surfaces. I used it anyhow, it worked out OK. (The self leveling stuff worked much better for my application ) I just wanted to reiterate, somebody in the comments said they automatically assumed that the tube had hardened and then when interacting with customer service, they said you got a poke a hole in the inner foil seal, somebody else in the comments said they’ve got the first tube and it was hard in the second tube was hard also, but I think that person made the same mistake! They didn’t know you’re supposed to puncture the thin foil inner seal down inside the nozzle.

Polyurethane is the hardest caulk to clean-up because it sticks phenomenally to just about anything. It also has long-life in exterior (UV, water, temperature), and is generally paintable. I particularly use this for masonry projects (which is what Sika is well-known for). It's a great product, with consistent coloring across batches. You can even apply it to pretty green/fresh concrete.Why 4/5 star?I wish it had a removable tip, which would make reuse after storage easier. I also wish the tip was shorter - it's hard to stab the metal seal when the tip is only cut to a fine point.

Great item! I have an old house, so this worked good on brick and around windows!

Best sealant you could even use

Worked great

Unfortunately the Sika product was VERY difficult to squeeze from my caulking gun, even using two hands!