epoxy/cement that really works??

[scrapman]

I tried 2 different brand name of epoxy to glue together rubble pieces of LR underwater.
None worked.
Any recommendation for the best foolproof method/brand name.
I read somewhere that Home Depot sells something that works for that application.
Thank you

 

[my way]

Epoxy will work underwater, just not in the usual manner,You have to make a ball of the epoxy and shove the pieces of rock together filling in any nooks and crannies. It locks the pieces together more than glueing them together. I hope that made sense.

 

[chipmaker]

One big problem with glueing live rock together is it contains lots of loose sediment and debri that is next to impossible to remove unless you actually pull the rock out and scrub that area and rinse it well. Other than doing that, just a film of even calcium cabonate on ithe spot yu apply epoxy is just that, The epoxy is applied to something other thsan the rock and does not make a good bond, so what has to be done is the epoxy has to be forced into the pores and holes and nicks etc to it sort of locks it inplace more than it adheres it in place. I just use a masonary drill bit ina cordless drill and use pieces of plastic rods (stir sticks, swizzle sticks, plastic welding rods, hobby / craft shapes etc form hobby shop) and pin my rock inplace. Just place rock as desired and drill through them and insert plastic rod to secure them and hold them from moving. Easy to pull apart yet stable enough to not fall apart or get knocked over by fish. You do not even see the holes or plastic rods.