question about silicone seal between counter and undermount sink
Hello all: pardon the cross-post from the Kitchen Forum, but I didn't get much response there, and thought I'd try my luck elsewhere.
Our granite installer did a hasty and poor-quality job with the silicone seal between our granite counter and the undermount sink. There's now something growing behind it; I can see it, but can't scrub it out, even with a narrow brush that exactly fits in the crack.
Is it a sign that the seal isn't good, and that further problems await down the line (ie, water getting past the sealant, dripping down the sides of the sink, and winding up in the cabinet)? Is it unsanitary? Am I loony to think I should strip out the sealant and try redoing it myself? If I should, what tools and supplies do I need for that? I don't want to call our installer back; it took him two visits, complaining all the while, just to do the subpar job we're stuck with now.
Alternatively, feel free to tell me that I'm worrying about something that doesn't need to be worried about. That's the outcome I'm hoping for, to be truthful.
Oh, one more thing. This same installer grouted, but didn't caulk, the granite where the countertop meets the 4" backsplash. He said the grout needed to dry first, and that once it did, *I* should caulk it, with clear silicone. I haven't yet. It looks like the grout is shrinking -- it doesn't fill the cracks the way it used to. I'm thinking I need to get going with the caulk. Consensus?
TIA for all these probably-idiot-level questions.