Can someone please explain...

[Oscar]

Originally Posted by justinl

how old is "older"?

Not sure how old this tube is. I will test again, 1 minute curing time is more like what I expected.

[Captainhemo]

I've been using the two stick stuff, "AquaScape Construction Epoxy" for quite a while and it works quite well.
I find it works best to press the putty into the rock where you want the coral, then press the coral to the putty