3M 4000UV Failure

[HopCar]

Just got an interesting article from Practical Sailor Magazine.
They are running long term tests on sealants and the 3M 4000UV completely failed at five years.
Where it was exposed to sunlight it reverted to its uncurled state. They described it as becoming chewing gum.
They spoke to 3M who admitted this was a problem with 4000UV that was manufactured prior to 2018. They changed the formula in 2018.

 

[ghost]

Bring back 3m 101

 

[HTurner]

I can testify that this is true. It becomes chewing gum -- silly putty. Cleaning it up was not a problem a putty knife scrapped it off with no problems.

 

[Comodave]

I had some issues with it so about 4 years ago I switched to Sika products and have been very satisfied with them.

 

[Dougcole]

I've never been able to figure out the difference between 4000 and 4200. I use 4200 as a less aggressive version of devil's paste--5200.

 

[rslifkin]

I've never been able to figure out the difference between 4000 and 4200. I use 4200 as a less aggressive version of devil's paste--5200.

Chemically, they're a bit different. In theory, 4000UV has better UV resistance for outdoor use. And for whatever reason, 4000UV has a better bonding strength to aluminum than 4200 or even 5200.

 

[DDW]

4000UV is a polyether, 4200 is a polyurethane.

FWIW, I have a whole deck full of hardware sealed with 4000UV done in 2009, and none of it has changed at all as far as I can tell. Pretty much none of it exposed to the sun - if you have big fillets of sealant around things you need to go back to sealant class.

 

[Sealife]

Used a b7nch duringmyrefit in 2014, its has all turnes to gum. Dreading having to do it all iver and have been contemplating what to use. Guess I can do 4000UV again....I assume no reparations are being made even with proof of purchase? I went thru cases

 

[dhays]

I used 4200 to mount my solar panel. Glad that it appears that 4200 doesn't have the same issue.

 

[Sealife]

Just read my post. Hate touch screens ��

 

[FF]

5200 Is a difficult choice as if the item ever needs to be removed damage to the mounting surface is common.

To my mind most sealing goop has a limited life so should be replaced as a task every so often. Preventive Maint.

My choice is old fashioned Dolphinite as the old sealant is a snap to remove with a putty knife , which in most cases is the long , hard part of the task.

A wire brush cleans the mounting bolts .

Would be nice to have a buck for every boat that lost its fuel tanks due a deck fill that never bothered with PM.

 

[diver dave]

Bring back 3m 101

I second that.

although I've since discovered butyl tape.

 

[koliver]

My window glass in the wheelhouse sliding door has blown bubbles along the edges throughout my ownership of this boat. Now I know why!

 

[mike66]

I thought it was just me. 3M after all. Thinking of using household door and window caulk instead. [emoji849]

 

[PaintMeRetired]

The new Pettit sealants are exceptionally good and thoroughly tested.

 

[Comodave]

I have been using Sika 291 for general caulking and in 5+ years have had no failures with it. I used it to caulk the teak toerail to the deck on our last boat. The PO had done it and the caulk would just peel off easily. I used the Sika 291 and it was good when I sold the boat in June. I did use the Sika primer on the teak per their directions. I didn’t want to have to redo it again so I actually read and followed the directions. Only downside was the primer was about $80 and has a shelf life of a year. But it worked…