Pointing up slabs

[OLD]

I have to do quite a lot of this soon thinking of getting a 'pointing gun' but what is the recommended mix and how wet etc., i need good adhesion the slab edges are tapered and mortar has failed in the past although they do not rock, any help here would be appreciated.

 

[StevieB]

I bought the Axminster one last year as I was laying a patio - it was absolutely pants. Nozzle blocked every 5 seconds and the amount of force required to eject the mortar was huge. You are supposed to have a wet mix and put in some plasticiser to make it flow but personally I found this didn't help at all. In the end I ditched it and pointed by hand. Havent tried any other makes but the Axminster one I would steer well clear of.

Steve.

 

[johnf]

A semi dry 3- 1 mix (so you don,t get it all over the slabs ) and point by hand is the way to go
It never sticks to those taper edge slabs

trust me I have done thousands of slabs

 

[head clansman]

Hi

as johnf says a dry 3-1 mix brush it in with a soft sweeping brush till all joint are full , then just run a trowel over the joints to form a hard surface sweep away all excess , and now it get a bit interesting get a water can with a spray nozzle and water the slaps lightly so the surface water runs into the joints and then leave till dry and hey presto all cement joints set.hc

 

[laird]

I found a normal 3:1 mix works fine in a grout gun, but only if you have quite a lot of plasticiser (washing up liquid) in it.

 

[Derek Willis.]

Washing up liquid rots the cement and it will go powdery after a while and fall out, use a semi dry mix as already noted, but if you can manag to brush pva into the joints firts more adhesion will be gained, well worth doing.