Sika Sikaflex-221, Gray, multi-purpose sealant/adhesive, polyurethane fast curing sealant, 10.1 fl. oz Cartridge

Good quality

Bought the grey for my RV which sits out year round, lots of exposure to Denver sun and weather as well as traveling vibration and movement. After using ChatGPT, it recommended this sealant, from other brands... can I trust an AI, we will see. First the product is very hard to squeeze from the caulk tube, (as mentioned from other users.) Second, I used painters tape to control the application in a straight line. The product is super messy, very tacky and requires to be spread, and smoothed ONLY ONCE. Three, Removing the tape was problematic, meaning the excess would string from the tape, then sometimes depending on the thickness, it overlapped backwards onto the newly applied sealant. I've worked with other products which have lost their effectiveness in a year, so another investment in this sealant is still out for a review a year from now. For as much as I think this might be the best alternative, the finished appearance suffers from previous applications of other products. Something I didn't purchase was the Sika Cleaner 226 or Aktivator-205 for Gel Coat finish... I did use the Isopropyl alcohol for clean up prior to application (which worked good) as well as after on my hands. Last, Chat said to not move the vehicle for 24 hours and product cures in 5-7 days .Also noted its cured by moisture in the air, how much? Denver is dry, but other western states are dryer.

The product works just as advertised, but unopened tubes don't have a good shelf life, in my opinion. I tried a new un opened, un damaged tube that I have had for 1 year and it was all hardened in the tube.

Wow fast drying!! For those that still have not figured out how to use this.. Here are the steps for you to follow Step 1 buy a calking gun that has a cutter on the Handle, also one that has a needle for poking the membrane.. Step 2 Insert tip into the hole above the handle, cut the tip.. Step 3 Poke a hole in the seal membrane inside the tip!! ( I like to swirl it around ) With the needled. Yes it is sealed still!! Even if you cut off the plastic tip! So when you squeeze the handle's.. it should come out easy.. If not you did not poke the membrane, inside the tip and good luck getting anything out, or not popping off the applicator.. We will see how well it works, soon. But a lot of boaters use it, so that is saying something!! P.S. Yes there are others that are not sure how to use this. But its ok. I am just glad your fixing or making something and that is great!! Your trying and that is the important thing!!

This went on great. Did entire 8k gallon pool with 3 tubes.

Fantastic sealant! I have a small gap between my foundation and crawlspace and this is the perfect elastic sealant to seal it. Works perfect. Smells a bit funny.