Porcelain Removal grout residue face of porcelain tile

[Makone]

Evening good people. I have a major issue with roughly 200sqm of porcelain floors grouted by my now very much ex apprentice. I have a serious amount of residue left on the face of the tiles. The kid was doing fine while I was watching over him but when I left him alone, well its all gone to rubbish. I have a good 4 plots (I'm subbing, new build) to go back over. I've been paid already and its obviously my responsibility. So yeah, nightmare. More fool me, you live you learn eh?
Just wondering does anyone know of where I can source decent polishing pads for my stone polishing multi speed grinder? Is this even a thing? Obviously I'd need to do it on a slow speed, but I have a lot of ground to cover so really don't wanna be doing this all by hand. Was gonna use it with an acid wash so any recommendations for that would also be appreciated.
Cheers in advance.

 

[One Day]

What type of tile? Polished, textured?
What type of grout? What colour?

 

[Makone]

Mostly polished, some polished-ish so not super high gloss but not too porous. Grout is Nicobond flexible silver grey.

 

[Makone]

What type of tile? Polished, textured?
What type of grout? What colour?

Mostly polished, some polished-ish so not super high gloss but not too porous. Grout is Nicobond flexible silver grey.
Apologies only just realised I can reply direct.

 

[J Sid]

porcelain or stone ?
internal I take it

 

[J Sid]

have you a pic?

 

[Makone]

porcelain or stone ?
internal I take it

porcelain, internal, kitchen floors 40 to 50 sqm each. no pics I'm afraid. Basically from what I can make out he rinsed the washboy sponge out about twice, three times max. Judging by what I found him doing halfway thru another floor.

 

[J Sid]

try
Produkte | Lithofin - http://www.lithofin.co.uk/en-gb/__i/Lithofin-KF-Cement-Residue-Remover

 

[One Day]

Silver grey is a life-saver I think.
I would try Fila Deterdek at suggested dilution along with some scotchbrite pads. Maybe even hire a floor machine for 200sqm as that's a lot of elbow grease.
Test first carefully for grout colour change and scratching tiles.

Nuclear option would be brick acid but could ruin the grout.

 

[Makone]

Silver grey is a life-saver I think.
I would try Fila Deterdek at suggested dilution along with some scotchbrite pads. Maybe even hire a floor machine for 200sqm as that's a lot of elbow grease.
Test first carefully for grout colour change and scratching tiles.

Nuclear option would be brick acid but could ruin the grout.

I'm taking all the grout out anyway as this kid really screwed it right up. Knocking up the grout too wet I think by the look of the finish. I'm absolutely furious with him if I'm honest. As the first 4 or so plots where I was checking all his work it was spot on. Just proper laziness.

Interesting what you're saying about the brick acid wash tho, as this site uses that for the build clean later on. They're a bit slack when it comes to protecting the floors, so they just acid wash them. However they then have been coming back to me saying the grout has colour variance. It hadn't occurred to me that the acid wash may be the problem, having never had a need to use it on any floor I've done. The back and forth between the house builder and the firm I sub for has been centred around what grout has been used. so we've just swapped from nicobond to weber. Bit of a game changer that. As they've acid washed all these floors before calling me back. Do you think the wash may have brought residue out on to the tile face? or is that a stretch too far?