Waterline tile repair work, proper material use?

[susa]

helping a friend out with a small issue on erosion of the white thinset/grout between the spaces of the wiremesh tiles at waterline. this is a very small mosaic pattern tile with small gaps between the individual spaces.

not consistently in all areas, but in some above waterline spots the white thinset (or grout) has been washed/dropped out and am wondering what is the easiest method of adding it back in?

Home Depot sells bathroom premixed grout/silicone/thinset materials and the easiest method I can think of is to locate a suitable white color grout mix that could be squeezed out from a tube and just lightly sponged into the spaces. This would have the added advantage of requiring no mixing and by standing in the water it may be entirely possible to avoid dropping any material into the water. I'm aware also there is a pool leak type of product that is also white and may be suitable for the same purpose. (there is no leak, the effort is purely cosmetic in nature)

the pool itself is in great condition so have no intention on draining water.

what's the best material in this situation?

 

[duraleigh]

You don't say how thin the gap is but I assume it is 1/8" or less. I would use non-sanded grout.....that's what it's made for. I have never used the pre-mixed but in the small quantities you're talking about, mixing grout is no big deal.

Home depot carries a very good brand of grout and thinset....Custom Products.

 

[acroy]

How about the 2-part epoxy "Pool Putty"

I've had decent luck on small repairs, can do it in the water. Not sure what the long-term reliability is, but a couple minor tile repairs have held up for a year now.

 

[Ranger987]

The Pool Putty won't stay the color you're looking for and will be more difficult to mix & apply than the thinset, in addition to being very expensive compared to the thinset for the same coverage area. It absorbs stains & changes color very easily - ends up a yellowish color pretty soon. I've known people to use a white silicone for small repairs, but large scale, it can be more difficult to clean the residue off the tile surface. The thinset can be sponged on easily & cleans easily as well. Other than ease of widespread application & clean up, I don't see any reason you couldn't try the silicone in small areas & see how it stands up. In either case, make sure the existing joint is clean & dry.