Need a good sealant

[noodle23]

So my reverse immersion cooler has sprung a leek. The expanding foam cracked so i replaced it with more expanding foam. In fact I used the foam designed for fish tanks. Its still not holding water. So what else could i use as sealant. Its not touching beer so im not worried about toxics influencing the beer.
thanks guys

 

[bengerman]

most expanding foam isn't designed to be watertight (even the aquarium stuff, assuming you're talking about Great Stuff's Aquarium and Pond. that's designed for sticking rocks together and is called aquarium and pond becaus it is black and won't kill your fishies)
go to your local ace hardware and get this stuff or this stuff

FYI, on both of those, go to your ace and get them, don't order online, unless you want a case of them