I posted about this before I believe. My builder suggested to use Sika Limestone Polyurethane caulk to seal cracks and chipping that has developed along the horizontal grout lines at the top of the tiles. I know that polyurethane caulk was suggested to me here also. I got some, and started a portion of the way around the pool. It looks ok except that the color of the caulk is way off from that of either the coping or the tile grout. So overall I'm not thrilled with it. My options appear to be: 1) continue with it around the rest of the pool (since right now only having done a part really points out the contrast between what has been caulked and what hasn't) 2) try to scrape out what I already did and perhaps use something else to seal the joint...perhaps a clear sealant (any suggestions?) 3) continue with the caulk and then paint it a color that matches more closely to the grout (need a really good waterproof paint that also would be resistant to pool chemicals...again..any suggestions?) Problem is the weather suddenly got much cooler here in PA and so at this point I'm not inclined to get back in the water to continue the work (I find it much easier to do the caulking from inside..especially since I use painter's tape along the tile so as to get a nice clean line with the caulk).
So...any ideas would be much appreciated. I guess that for this application polyurethane is the best choice due to the lateral movement that could continue to occur with the coping. It appears that the coping has broken away from the mortar bed (at least based on the 'run a hammer along the coping' test. This alone is disappointing since the pool was just renovated 2 years ago.
Thanks for any thoughts...