Rust removal from marble tile.

[saveasteading]

One of the screws on our shower has rusted to failure, leaving a stain.

For replacement I will use a branded SS screw, as I always do, in recent years, for wet locations.

I've tried baking powder, toothpaste, detergent, vinegar and all combinations ( yes, including mixing acid and alkali, as at least there is bubbling.)

Any ideas? 

Perhaps a big SS or chrome washer if nothing works.

[joe90]

It looks like the rust is under the gloss surface of the tile, marble is quite absorbent so might be within the tile 🤔. 

[saveasteading]

1 minute ago, joe90 said:

under the gloss surface

Yes I'm afraid so. But if it went in, and it's visible, then Snibbo might also get in, and neutralise or remove it?

[Gone West]

A friend used oxalic acid to remove rust marks from timber. I used to use phosphoric acid to clean rust from car parts. Don't know what the affect would be on a wall tile though.

[Alan Ambrose]

Remove tile & replace? Have a spare tile to practice on? - maybe try hydrogen peroxide with suitable precautions. Otherwise I’ve had custom ss parts laser or waterjet cut - generally you need to supply a drawing and a dxf - but there may be someone out there who’ll do the little bit of cad for you on the fly. Of course you’ve replaced any other similar steel fixings…

[saveasteading]

13 minutes ago, Gone West said:

effect would be on a wall tile though.

Strong Acid on marble could be a problem.

I've probably got spare tiles but rather not.

I'm thinking of a Grohe "rosette" plate. 65mm.  I don't know what their intended use is, but it should be OK.Except that I really need 80mm.

 

 

[saveasteading]

I've now seen SS plates on ebay, 75mm x 3mm thick. I suspect the 1mm thick will be not sit tight. Then just drill a central hole for the screw and plonk on with silicone.

[Kelvin]

I bought some German rust removal stuff and it worked a treat on our tiles (same issue) at our previous house. I shall try and find it. 
 

 

Edited February 17 by Kelvin

[Pendicle]

I used this on my bath to get a rust mark out successfully 

https://www.protilertools.co.uk/product/lithofin-rust-ex-non-acidic-rust-stain-remover-500ml

[nod]

Remove and replace 

Nothing will stop that 

[saveasteading]

20 minutes ago, nod said:

Remove and replace

I know. But I will try one of the above and report back.

 

I cant remember if the rusty screw was provided or if its my own fault. Either way, in recent years I have invested in Fischer SS screws to fix showers and grab handles and am impressed with them...very hard head and a very good grip...and no rust.

[MikeGrahamT21]

Bar tenders friend, if that won’t shift it nothing will.

 

if it’s true marble though the stain will have seeped in, but still worth a shot, it’s pretty cheap

Edited February 17 by MikeGrahamT21

[Alan Ambrose]

Yeah Fischer is a good brand.

[Pendicle]

Have you tried this

https://marble.com/articles/how-to-remove-rust-from-marble

[saveasteading]

Toothpaste, bicarb, vinegar didn't work at all.

 

 I found the Rustex to be readily available online. Used that in multiple brush on/ wash off applications.

The rust turns purple then comes off. Most of it anyway. the remaining stain must be embedded, yet the chemical doesn't reach it.

 

I haven't worked out why the stain is less beneath the round plastic fixing.

Going to refix for now.

Thanks for the advice.