Yikes. This is outside both JJ and my expertise. So we both decided to procrastinate doing anything because we thought it was going to be a much tougher job. I know, smart of us, huh? So finally, 3 weeks after the discovery, I used my handy-dandy google skills and found a how-to video. The first video was the mix your own mortar type and I thought, "Psh no, I can't do that!" On to the next video. This one was way more my style. The mortar came in a tube, and you applied with a caulking gun. Easy-peasy.
First step: Brush out any debris and leftover mortar. I used a paint brush to get in there.
Second step: Go to work. It says to get in there deep, but no thicker than 3/8".
And yes I purposely avoided the "that's what she said." This is what it looked like after:
Third Step: Now here's where the video said to use a jointer to smooth it out and give it the concave look. But I have the memory of a goldfish and forgot to buy one, so I used my finger.
I think it looks fine though. I'm pretty sure the piece to the right is going to crack off soon anyways so I'm not worried.
Now I'm just crossing my fingers there's no more ants.