Cleaning grout off tiles.

No-one? I can scrape it off with a chisel without damage to the tile. Was hoping someone knew a quicker way.

cover in kitchen roll and keep misting it with a plant sprayer for a day or two?

Residue as in a thin film or ridges of set grout? For the former just use the shower and wipe down the tiles after every use it'll eventually go. Even the ridges become slighly less attached after "a while".

Naw, not with a cement based waterproof grout. Spray with a mild acid, citric or calgon or kettle descaler or WHY. Might be able to make a paste with citric spread on scrape off hopefully with the grout or just work it in/around with an old tooth brush. Any scraper needs to soft and not metalic.

Remove and replace the tiles.

Bill

I don't think it's a mortar based adhesive. Not the sort you'd use for tiling outdoors. More water resistant than waterproof. Fine for an occasional use shower room walls.

There is stuff called HG cement grout film remover 1L - "the grout remover for all types of tiles and flagstones"

There's probably a PDF somewhere giving its precise chemical composition and whether it contains anything over and above the standard cheaper recommendations which are of acid of various types/strengths

michael adams

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The packaging will tell you. Or just keep it wet for an hour or two ordinary grout/adhesive will soften, waterproof won't even notice.

Thin film may come off with a non-scratch scourer.

Likely so.

Due to my hands getting a bit arthritic I was hoping their might be something that fitted a power tool.

I find a box cutter about the right combination of flexible and blade width for scraping off bits of set grout. The waterproof stuff once fully cured is only going to come off by physical removal.

If you have a steady hand a stanley knife with the blade in paper scraping configuration will give you an even wider scraper edge.

Polishing mop and polisher?

acid

Well spotted. So its main constituents are

Phosphoric acid - which is found in soft drinks and gives them their tangy flavour

Oxalic acid which is found in rhubarb leaves and the green bits of potatoes

ethoxylated isofridecanol which is found in everything from washing and cleaning products, to air care products, greases polishes and waxes.

So that rather than fork out £8.59 for a litre of HG cement grout film remover

just boil up some rhubarb leaves in a saucepan of supermarket lemonade and sling in a bit of washing powder and floor polish.

michael adams

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The clue to the effectiveness may be in the word "film" and it may be effective on the haze that is left after a brief wipe-off rather than removing bulk material.

on a matt surfaced tile?

Didn't say anything about any polishing compound. B-) Also thinking that a polisher is going to far less agressive than a cloth wheel on a drill or angle grinder.

What would that do to the actual grouting which is fine?

Those green plastic pot scourers seem to do it OK. Without scratching the surface. A wheel made of that to fit a power tool would be great.

You can buy various grades of "scotch-brite" wheels/discs, e.g.