mortar + soap = sticky?

[Tony]

I overheard a conversation where a guy was trying to fill a block wall cavity just at the bottom next to the floor, and he only had access at the bottom. He said it's hard to get the mortar to fill the holes in less than 3 attempts since it tends to run out even thought it has less water than he normally uses for mortar. He was told to add some dish soap (detergent) to the mortar and it will either get sticky or maybe just very thick? Ever hear of anything like that? I googled it and found nothing.

Sort of related, I once bought some dish detergent at a $1 store and I normally water it down a bit. This stuff from the $1 store got thicker as I added water! WTF? Sounds like a way to make people think their soap is really concentrated?

[harry]

Adding detergent to morter is an old trick to make the morter more plastic, ie squishier to make bricklaying easier.. You can buy pukka plasticiser for the job. You don't need much to have a hell of an effect. It works by entrapping air bubbles in the morter as you mix it. It also weakens the morter.

[Jon Danniken]

Sounds like a "poor man's" way to get modified.

Jon

[mm]

Well, how many loads did the soap do, and how does that compare to other soap?

[Tony]

Adding the water without a doubt made the detergent less effective even though it was more viscous. Of course there was a point were adding water to the soap started loosing it's viscosity. It was not worth the $1 I paid for it.