Need Advice on Caulking Around Sink

[TromboneAl]

The caulking between our porcelain sink and Formica counter top had become stained, so I removed it, cleaned things up, and applied new caulking.

It looked great, but four hours later, it was all stained again. Apparently the rust or corrosion from the sink soaks through, and, as you can see, it looks really bad.

What tips do you have for fixing this? My current thinking is to remove the old stuff, spend a lot of time scraping and cleaning under the lip of the sink, then paint on some kind of sealant or anti-rust paint, then add new caulking.

Another thought is to find brown caulking -- seriously.

 

[cute fuzzy bunny]

Use silicone instead of latex.

The latex takes up the stain...silicone wont, and the silicone will also stabilize the sink better as its a harder cure. Tough to clean up and hard to remove without a caulk remover, and you cant paint it.

I only use latex when i'm going to paint the result. Otherwise silicone rules.

And there IS brown caulking, I've used it several times to seal the edges of a dark brown floor.

 

[Webzter]

Get some mineral spirits and a rough spounge and clean around the sink. This will remove all of the old caulk. Don't inhale, drink or soak in the mineral spirits.

Tape off the sink and countertop with some painter's tape or regular masking tape.

Make sure the area is bone dry.

Buy some 100% silicone caulk (like Fuzzy said) in white (it's generally white, clear or brown) and caulk around the sink. Now, here's the rub, you need to let it cure 24 hours before it can get wet.

100% silicone is messy and tougher to tool than latex. You can use a wet finger but it's a mess to clean so just aim for a nice bead from the start. Don't go back over caulk once it's down, just bead it one way from the start and go over again the next day if you have gaps.

Another option that might work well... did you use latex caulk the first time? If so, check out siliconized acrylic caulk. It's paintable but gives you the better sealing protection of silicone. It's much easier to tool and clean as well... it also comes in white, clear, brown and other assorted colors.

You might be able to get some kilz primer and a small (I'm thinking craft-size) brush or q-tip and paint the underside of your sink after you break the seal. That should do an admirable job of sealing in whatever is leaching out. Wait two hours for it to dry berfore you re-caulk.

 

[OAG]

I would only add to all of the rest is use a HAIR DRYER to be sure the seam is really BONE Dry. I would think that the correct caulk (as already mentioned) is critical -- and in my experience do not opt for the cheapest stuff. IMO that is the worst area to caulk in a house. Under mount sinks are great, but from your picture not an option.

 

[Martha]

I agree on the silicone caulk. Instead of using a wet finger to smooth it out, dip your finger in mineral spirits. Works real nice. I just did it around a bathtub and it looks great.

 

[TromboneAl]

Great advice, thanks. I'll pick up some silicone caulk today.

 

[TromboneAl]

Well, here's how the work went:

Here's another before picture, showing how bad the problem was.

I realized that I could lift the sink up a bit so that I could sand and paint it, and get all the old gunk out.

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I had some primer around, and after a lot of sanding under the lip, gave it a few coats of Kilz.

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[TromboneAl]

I put the new caulk on, using 100% silicone. And here's the final result:

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It looks good, but here's a place where, about 48 hours after finishing, I may be seeing some brown stains appearing again. I'm hoping it's a false alarm.

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If the stains come back, I guess I'm just going to have to live with it or buy a new sink.

 

[TromboneAl]

Caulking Story: A man's five-year-old wanted to help him caulking the tub. He wanted it to be neat, so he explained to her that it was still soft, and she shouldn't touch it until the next day, after it was hard.

When, later that day, when they were in the grocery store line, she announced to everyone:

"I can't touch Daddy's caulk today because it's soft. I have to wait until tomorrow when it's hard, then I can touch it."

 

[cute fuzzy bunny]

Looks like your old sink is rusting Al. Considering you already had it halfway out you might consider a new one.