Grout not uniform colour

[Dumbo]

I had the same problem with dark grey Mapei rapid set grout on some pebble mosaic, real bad

I bet you would not of had that problem on pebbles if you could of used a traditional w

 

[Dumbo]

I had the same problem with dark grey Mapei rapid set grout on some pebble mosaic, real bad

Wide joint grout

 

[macten]

Diluted phosphoric acid works a treat if it's caused by excessive polymers. Obviously you wouldn't use that on natural stone but will be fine for your porcs.

 

[hmtiling]

I thought mm2 was efflorescence free?
I find it more user friendly than ucp and ucp 113 is the only one I've had go patchy.
I used the fuga fresca which sorted it nicely.

 

[andy-p]

I mostly use mm2 and dont have any problems with patching but as for Mapeis ultra ? well...

 

[On one]

I used an old part bag of Gun Metal MM2 to do 4m2 of floor tiles on Thursday (so old it most likely was out of date)
It was OK when I left it!..................................
Not sure about the morning after though

 

[One Day]

I think too many tilers like their grout too wet.
I like mine to be firm, so there's less water in the mix to begin with.

There's also a tendency to not bother waiting until that golden few minutes when it's started to harden up in the joints.
Some grouts, i.e. TM 3000 - it seems you can get away with washing-as-you-go.
Others don't like it though.

 

[Dumbo]

I think too many tilers like their grout too wet.
I like mine to be firm, so there's less water in the mix to begin with.

There's also a tendency to not bother waiting until that golden few minutes when it's started to harden up in the joints.
Some grouts, i.e. TM 3000 - it seems you can get away with washing-as-you-go.
Others don't like it though.

Trouble is mapei ucp dries a lot faster on Tile face than in the joint you then scrub Tile and wash grout out of joint . Why use mapei ucp well because customers want the right shade of gray . I remember when their was one colour of gray

 

[Viceroy]

I've have had issues with coloured grouts for years, Mapai being the worst to use, drying to quick on tile surface and still soaking wet in the joints, I have stopped doing a 2nd wash with clean water now on coloured grouts, I'm letting them dry for longer and using clean towels to polish off, I deffo think its too much water during the washing off process that causes patchy colours, out of all the coloured grouts I'm finding ultra's grouts are drying the best

 

[One Day]

The best I've used by a long shot is grout 3000. Especially natural grey which basically seems to go with everything!