repair crack between stone / mortar on waterfall spillway

[jeffreymlewis]

Hello pool experts!

Last year I noticed a gap forming between the mortar and rock on my waterfall spillway (see picture below). I thought it would be a good idea to inject a concrete/masonry caulk into this gap as a preventative measure.

However, I can't figure out which material to use. The area to be patched is in constant direct sunlight, so polyurethane is out (since it can't withstand UV rays). A silicone masonry caulk can withstand UV, but silicone is not recommended below the waterline. (This is the waterfall spillway, after all, so it will be covered by water 24x7.)

Then there are Polysulfide products (for boats and such). These can withstand UV rays and are fine below the waterline. However, I cannot find a polysulfide caulking rated (tested) on concrete/masonry. Any ideas?

Thanks,
Jeffrey

 

[duraleigh]

There is no UV penetration below the water line.

Additionally, I have used poly caulk in full sun for years......very acceptable.

I would use that stuff from HD or Lowes that has sand embedded in it for a decent texture match and never look back

 

[FamilyGuy]

I agree with Dave. Check the tile section with the grout. They sell sanded grout caulking. Chances are they have a close match to your color

 

[jeffreymlewis]

Funny, I was just in the tile section of the hardware store the other day looking for caulking for the kitchen counter, and found this grout-like caulking that I never knew existed. Thanks for the advise, I'll give it a try.

- Jeffrey