Removing epoxy grout from blue stone pavers

[Morne]

Hi - I used Dunlop epoxy grout to repair the grout between the blue stone coping tiles around our salt pool and to fill in some holes in the coping tiles. However, as it is drying I see what appears to be an epoxy grout haze or epoxy haze on the blue stone. See pictures. What is my best option here - is there a product than can remove this to match colours back in with surrounding tile. Note I have used a soft bristle brush with white vinegar and water but not making a difference…..

Please help

[Jewelleryrescue]

Hi @Morne 

The reason you using epoxy grout is you know it seals and bonds well. Nothing  wrong  with that 

I would use an orbital sander  with 240 gt sand paper and gently sand the grout  off you may need to sand some of the tile surface (Test in a  blind  spot  first.)   Sand ligthly try a smaller blemish first.

Afterwards  the stone will benifit from resealing. if they where done.

Plan B seal the tiles  so they all look  wet and blacker.  Try plan A  first as the best solution.

Hope this helps.

[MitchellMc]

Welcome to the Bunnings Workshop community @Morne. It's wonderful to have you join us, and many thanks for your question about grout haze.

It sounds like you're dealing with a couple of potential issues, but I'm a bit confused about what exactly you're experiencing. I’m not seeing much grout hazing around the grout lines, which is what I’d expect if it wasn’t cleaned off immediately or if it penetrated the Bluestone pavers. Instead, it looks like the speckled sections you mentioned may be areas where you've filled multiple holes in the coping tiles.

Since Bluestone tiles are porous, you need to be exceptionally careful when grouting them, especially when they are not sealed. This becomes even more of an issue when using epoxy-grouts, which are even more important to remove immediately. Epoxy grouts can be difficult to use, even on glazed tiles. On a porous tile like Bluestone, any excess on the surface of the tiles will soak into the pores and might not be able to be removed.

Could you show us an image when the areas you've cleaned have dried and are not dark due to moisture? Also, could you confirm whether the speckled sections are due to using a white grout to fill holes in a grey tile?

Please let me know if you have any questions.

Mitchell
 

[Morne]

Hi Mitchell

thank you for your reply. The photo shows the miss match in colour. I did use a sponge to clean it but I think because the stones are porous the epoxy soaked into it and as a result the darker patches you see in the photo.  Looks like my only option is to seal the coping tiles so that the tile is the same colour….or is this likely to make things worse….? Any recommendations on a sealer for blue stone around a pool?

regards

[Morne]

Thank you for your reply. I think the seal option is probably my only option as I am a bit scared sanding it. Any recommendations on a good sealer for blue stones?

[JacobZ]

Hi @Morne,

I see two distinct sections in the discoloured patches, the darker sections which look wet and the white speckled sections which look like there is grout buildup in the pores of the stone. 

If you were to use a sealer, this would likely reduce the visibility of the dark sections, but the lighter sections would still show quite prominently. The sealer would also set them in place, meaning they would not have any ability to fade naturally, so we should aim to reduce these speckled sections as much as possible before moving forward.

It would be worth trying a fine tool like these Craftright 4 Piece Hook And Picks to gently scrape the white speckled sections before washing them with clean water. You are looking to break the contact between the grout and the surface beneath so it can be washed away. Be gentle while scraping so you don't scrape away the actual stone beneath.

You should give this a try before moving on. 

Let me know what you think.

Jacob