Hybrid Adhesive Sealant,3 oz,White

We have used this stuff to seal in a wet, industrial environment for the last 2 years, Once it is set in place it does not leak or break loose like the silicone based sealers we have used in the past. It is difficult to get apart once set but that is great in my opinion its doing its job well.

You see a lot of negative reviews on this product after people don't follow directions applying it. First off, it's meant to be flexible, secondly it needs time to cure. If you can figure out how to apply it you can figure out how to read the instructions; clean and prep your surface before applying.

I am on my third tube of 4000 uv fast cure. All bought at different places and times. I have not had any of the problems others reviewing have had. I use it completely submerged doing a pretty demanding adhesive job, holding up the spray ring in my driveway fountain. No problems at all.

Great working size with true fast cure performance

Horrible. I had high expectations for a 3m branded product to last. I used it to caulk around my sailing catamaran windows and it barely made it a year before cracking and within only a few months it turned yellow. Absolute trash of a product. 3m you guys need to recall this one and get back to the drawing board. Switching to Sikaflex.

Application by professional boat painter in boatyard in May 2018 while out of the water. He used it to seal the seam between our rub rail and hull. It was Yellowed, mildewed/moldy within 2 months after being back in the water June 2018. Very disappointed in this product.

Bought 4 tubes fron large US marine store. Have used part of first tube and after two days it is still soft and sticky. Hoping it will cure before becoming contaminated with dirt etc. Dissapointing to buy a product called 'fast cure' and have this problem.

I am a professional recreatioinal marine tech with over thirty years experience and fully satisfied with multiple 3M products. However, based on product claims, I decided to try 4000uv beginning several years ago. I have discovered that it degrades in volume (wears away) and begins, in sections, to soften to an oily peanut butter consistancy that will wipe loose with a rag. 3M should revisit there testing protocols and remove or improve this product.

I recently refinished a sailboat using 4000UV for most deck fittings, and while I don't yet have any leaks (4yrs later), the caulk that is exposed to the elements is falling into little pieces. This makes me nervous as I would REALLY not like to remove the toe rail and all other hardware if this fails. The Butyl Tape that was original to the boat lasted almost 40years. It remains to be seen how long this 4000UV will last. I would definitely not recommend this marine sealant. I'm surprised 3M is still selling this product after many reports of failure. Considering how much was at stake with the compound I used, should have gone with a trusted product like 4200. Wondering if there will be a class action lawsuit.

We restored our Boston Whaler last summer and sealed out the deck plate and removable gas tank cover. Not even a year has passed and it is already cracking. So we started to remove the 4000 and found the top was dry, chalky, and cracked and in some spots it was still sticky and wet.