over on RJ's DILA forums he has posted up a new method for water proofing his new SmartString RGB nodes.
he is using a product called PlastiDip, thinned down to almost like water consistency, then just dunking the whole string in the solution. PlastiDip is a clear flexible rubber coating and UV safe. It looks like a pretty good way to water proof the strings BUT, and there is always a but , it is expensive, especially here in Aus. The sole importer of the stuff in Australia is the only person that I could find that sells it, via an Ebay store, and it is very expensive compared to overseas prices - like 3 times more expensive, then add delivery on top of that too !!
the ebay shop does sell a big tin of the stuff for about $300 so maybe if you knew a few that were interested you could split the cost.
There was a fair bit of discussion about water proofing rgb led string last year, which would apply to normal leds strings also.
At the time I purchase a couple of products to test with.
1. liquid electricians tape, it was a little expensive but it did not hold to the wire to well.
2. Plastidip was tested. expensive, it was purchased from the ebay store but i bought the UV stuff to test. worked well.
3. Andrew found "Sellys All Clear Brushable Water Barrier" from bunnings fairly cheap and worked well, just be sure to let it dry for a while.
Best choice I found was the Sellys stuff, cheapest and can be thinned also.