what would turn my new 3M 4000 UV white sealant, yellow?

[sadworld]

I just sealed up a bunch of stuff and the deck a week or so ago and i noticed it has all turned yellow and looks like crap! There was a lot of maple and other tree debis on the boat and we did get some rain. Could that be the culprit? More importantly how do i get it white again? Thanks...

 

[scoflaw]

3m does have a tech line

 

[Buckeye Boater]

Were all of these caulk lines exposed? Pollen levels have been extremely high - wondering if a layer of pollen could have settled on the caulking before it had time to cure.

 

[Skuza]

I had what I believe to be a bad batch of caulk when I redid the rub rail a few years back. It eventually turned dark and started to crumble in spots. It resembled plumbers putty in other areas. I don't recall the brand but believe it was something from the boat store. 2 years ago I recaulked the base of the windshield and couple other things with GE White Silicone II from the big box places and guess what? The stuff is holding up WAY better and cheaper too.

In your case not fully cure with the heavy pollen possibly like we have here in MI this year could be the culprit. Try gently wiping it with some mineral spirits or just soap and water.