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

Good quality

Great sealant for my box truck build, strong but flexible

I work with this sealant, it's spectacular

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.

Excellent caulking

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.