Slate pre-grout sealing tiles look dull/hazey

[Dave2811]

Hi, my name is Dave and hoping someone can provide some insight to my problem: Just installed 3x6 kitchen backsplash tiles, copper rust slate. Everything going great, love the look and want to keep the natural look of the slate - no color enhancing or gloss. Then we put on first coat of pre-grout sealer (water based, Premium Gold Slate & Quartzite Sealer made by Superior Adhesives & Chemicals = $50/quart). Application was easy enough, followed directions, didn't put too heavy of a coat on, left on for 5 minutes then wiped off. Compared to pre-seal appearance, ENTIRE backsplash now looks dull and muted, I guess I'll call it hazey. Don't want to put on another coat or start grouting until we address this problem.

Tile store staff said maybe we didn't wipe enough of the sealer off and to put on another coat to re-emulsify original coat and being careful to wipe off... but we were very careful when we applied and scared to put any more on. Read another website that said water-based natural sealers are tougher to apply and are prone to this hazing/dulling effect...and that solvent based natural-look sealers are easier to apply?

Any thoughts? Should we stick with the water-based sealer and try another coat - and if so what are we doing wrong? Is there a way to "remove" the first coat of sealer that we've applied like vinegar/water, or do we need a chemical? Can a solvent based natural-look sealer be applied over the water based sealer? Any other suggestions for getting rid of that dull look? Any other sealer type/brand suggestions?

Thanks a ton in advance, learned alot from the forums here! Dave

[Brad Denny]

Hiya Dave,
Never used that product, but it appears to be more of a post grouting type sealer. It could be used pre-grouting, but I'd have used it pre-install, cleaning each piece before sealing it. If you seal it without it being clean, that could result in hazing. I do think the store's assessment of the problem is probably accurate.

When we seal before grouting/after install, we like to use a grout release as it comes off easy enough after grouting to make ready for final sealer. You might want to contact the manufacturer to get their recommendation on which steps to take next and refer back here if they offer no help.

[Davestone]

You can try Brads' suggestion,or move ahead if you're handy.
I would try rubbing a small secton with MEK or acetone,maybe even xylene,or if there is an msds you can get info as to what would remove it.Penetrating sealers are tough to remove when absorbes,but simply grouting the stone may remove the excess.
Yes the water based sealers tend to white haze easily,i rarely use them.

[MDS]

Tile store staff said maybe we didn't wipe enough of the sealer off and to put on another coat to re-emulsify original coat and being careful to wipe off...

I would not expect a water based sealer to re-emulsify itself. That is a trick that usually does work with solvent based sealers. You were wise not to follow their advice.