Thanks guys really appreciate it, all very helpful. I'm not a bricklayer by trade but am familiar with the way to lay bricks. I might have to hire someone to test them for me, link that was sent is for powdered mortar tone not the liquid mortar tone.
One thing which I read was to use "up to 1 litre per litre of gauging water"
This was on ever build websites, I'm using cromar product which can't be that different.
I'm not understanding what up to 1 litre per litre of gauging water. I've spoken to a brick layer here, they use per mix about 30 litres, surely this can't be right, to use 30x 1L liquid mortar tone in one standard wheelbarrow mix? (120 - 130 bricks)
209-Liquid-Mortar-Tone-V1.1.pdf