my pond

[marktench]

Originally Posted by coasty

At last a thread where I am an expert,,,
Washing up liquid is used as a plasticiser this improves the workability of the mortar, However it will not improve its final strength in fact to much will weaken the mortar. PVA is usually used as a bonding agent,, ie you would apply a weak solution onto a smooth surface to enable the mortar to bond properly.
I would suggest you use a mix of mortar about 1 to 4 to 1 to 6 by volume of cement and soft builders sand. Very important that you fully mix the cement and sand together dry before you add the water, and add it a little at a time.
I would use sharp sand to bed slabs on when creating a path or to make concrete, however to make a mortar you need to use soft sand.

Clean of the underside of the stones well remove all lichen etc. and put down a good blob of mortar and tap the stone on to it. and leave for a few days to harden. make sure the mortar spreads to all the underside of the stone, Otherwise it will rock and become loose.

Good Luck,,,,

Thank you very much for that.