water feature glue

[MrFaulty]

Hi, I am looking at making a water feature by gluing/cementing river stone to fibre cement (10mm thick) - tjhe fibre cement board is 600mm x 2100mm so quite large. Can anyone advise what is the best glue to use, I have b een advised by a builder than sand and cement will fail. I have been told Ardex? will be best? polyurethane?? any suggestions?

Thanks
Ben

[Coustralee]

I'm not really sure when it comes to glues but I'd try selley's Knead-It.

I've used the Aqua one to stick together bathroom fittings and patch a rainwater tank. You knead it together and it makes a putty that will dry rock hard.

Some people seem to be using it to bond coral etc together in aquariums.


"A versatile hand kneadable, fast setting co-extruded epoxy repair system that can be used for repairing a multitude of things. It is especially suitable for application to damp, wet or underwater substrates. It comes in a handy roll form, with the white hardener encapsulated in the aqua green resin part. The product hardens in 20 – 30 minutes after mixing, to a white solid material."

[hoddo]

Epoxy will work but may be to expensive for an area that big. I would be inclined to use a good cement based tile adhesive like Supefixall by ASA (since bought out by bostik) to make it even stronger add megalastic liquid. This is what I use when laying glass mosaic tiles in swimming pools.

[MrFaulty]

Yeah, the kneed it would be too expensive but alos not flexible at all - believe I need something with flex to offset the differential in expansion rates between the fibre cement and the rock. Will try that Bostik product I think.

Thanks
Ben

[hoddo]

Adding the megalastic liquid instead of water is supposed to increase the flexability and adhesion but it does reduce work time and is a bit harder to work with. Try to work out of the direct sun as heat will set the glue alot faster. Apply the glue with a notched trowel and press the pebbles onto the fibre cement sheet and clean up as you go with a damp sponge as once the superfixall dries its hard to remove

[MrFaulty]

Results
Finally fjnhished my water feature, no photos yet though. I glued the polished black river stone to the compressed fibre cement (12mm) board using sikaflex polyurethane, then the outdoor sikaflex glue, both seem to have held well; I did etch half the rocks with a masonry blade on an angle grinder but stopped doing this after removing a small piece of my finger!

After the glue had been allowed to set for about a week I framed the board and used ardite to flow in betwen the rocks to a depth of about 3mm.

A few days later I wrestled the board into place and was suprised that it held together (so far).

Will get the pump working in the next week or so and put some photos up

[Pam]

I can't wait to see the results - it sounds fantastic.

[MrFaulty]

Unfortubnately the pump turned out to be a bit small for the head (approx 1.8 metres) and hence the waterfall is more of a watertrickle Will have to do for a while