I'm wondering if the discoloration is from limescale deposits on the surface of the sink. I know you said you don't have hard water but have you tested the water to be sure? Mild acids like vinegar or citric acids are recommended for dissolving limescale deposits. You said you had tried vinegar and elbow grease but am wondering if acids would need more time to interact chemically. Have you tried an overnight soak (stoppering and filling the sink with water and vinegar or citric acid)?

Just one more reason to go plain old stainless the workhorse for kitchen sinks and IMO that will never be like new again IMO the vinegar just added to the issue . Have you tried talking to the manufacturer to see if they have some solution . Mine would be get a new stainless sink.

I am surprised at this. I have had two Blanco Silgranit sinks in anthracite in two different homes, and they both looked like new after several years of use. If you hadn't said what you cleaned it with, I would have guessed it was harshly cleaned with a brillo pad, or Soft Scrub (not soft!) or BarKeepers Friend which is great normally unless it's been left to sit on the surface for too long.

Replace the Blanco with an Elkay please. 3 hour job, tops, plumbing included.

We don't even have soft scrub in the house. I wash it with Myers dish soap and a sponge. Though yesterday I tried washing it with dawn and a sponge. I have contacted Blanco, but have not heard back. We have used barkeepers friend to clean pots and pans, but if anything, the powder gets on the bottom of the sink not the sides, and I always hose down the sink after we use it because it does infact leave a white scum in the sink which I do not like, so I get rid of it promtly. I was thinking of using a lime scale cleaner, but first want to hear from Blanco. I don't want to make the problem worse. I know I could put mineral oil on it to disguise the problem, but that doesn't seem a satisfactory answer as it will have to be reapplied frequently.

Joseph, why do you prefer the Elkay?

Well, I was going to link one of the several threads in which I made lengthy comments detailing the method I use to clean off the ugly white streaks on my Silgranite sinks. I had posted photos of the before with the white stains, and then after my cleaning/oiling process. I have two Cinder colored sinks in each of my houses and both had the issues. I am pretty sure it is from hard water or certain minerals.

I am not sure why, but it seems they all have been deleted. 🧐 Hmmm. Very odd. I looked through every single thread which included my user name and Blanco Silgranite.

The only comments I could find were the positive ones I had made back several years ago. They were from when I still loved my sinks and before the white stains had gotten really bad.

Now don’t get me wrong, still do love the look of my Cinder sinks! That is, after I do my cleaning ritual and they look brand new for a couple of days. I am NOT saying that you should not buy this brand of sink! Although, I would only recommend them to anyone who does NOT have hard water.

And yes, my streaks are only on the sides too. No idea why that is. I will post the photos again here. Hopefully they don’t get removed again.

Before

Close up showing the stains better.

After cleaning and oiling.

It slowly returns to the before in about 2 days after you use the water again.

What products did you use?

"Joseph, why do you prefer the Elkay?"

Order the samples of each. The Blanco look like glued-together gravel compared to the Elkay.

I mix baking soda with vinegar (it fizzes) into a thick paste consistancy. I use a blue anti-scratch sponge and scrub the paste all over the sink pretty hard for several minutes. I then leave it on pretty thick for about an hour. I wash it off and let it dry. I then do that process again until my arm hurts and again let it thoroughly dry. It has to be completely dry before the next step.

After that, I take a wad of paper towels and saturate it with mineral oil or coconut oil. I smear it everywhere letting it soak in real good. It will look like that photo I posted above.

Now the key is to put something across the sink to block people from turning on the water for at least 6 hours. Better yet, let it soak overnight.

It will look brand new and gorgeous for a couple days. Then the streaks slowly come back over the next few days as the oil is washed away by the water. It will return even faster if you clean it with a soft sponge and dish soap once a day like I do.

I’m over it. 😩

^ sounds awful.

Stainless. I think these composites look like laundry sinks in a basement. Frankly, the only place I would consider one. They are reinvention of a wheel.....when quality stainless is easy as pie and "forever'.

Wow, what a process to clean a sink, @rebunky! It shouldn't be that hard to clean something you clean things in. I'd replace it with a stainless steel sink--my favorite sinks are made by Franke.

So much easier to clean a stainless sink who wants to spend an hour cleaning a sink ever switch it out and get on with your life.

Just like we don't condemn all natural stones for countertops over the poor selection process, lack of testing, and fabrication errors, we can't condemn all composite sinks over the poor performance of one particular brand.

Yes Joseph, it is awful. Have you replaced very many of the silgranit sinks with this issue? I don’t know what else to do at this point but replace them. I sure wish Blanco would address this issue because I know it is happening to many others.

If you include the scrubbing time, the 1 hour that the paste sits X2, the 1 hour dry time before oiling, and the 6-8 hours for the oil to soak, we’re talking 10-12 hours that we cannot use the kitchen sink at all. That is why I time it so that the oil soak part happens while we sleep. I know it is not worth all the trouble, but I don’t want the stains to get even worse.

One time I forgot to cover the sink and faucet with a big towel during the wait time, and my poor husband turned on the water to wash his hands. I let out this ghastly sound that I have never made in my life. It scared my dogs so bad, they went from deep sleep to growling and barking instantly. I made my husband literally jump. 😂🤣

It is so frustrating too because all that work does not last. The streaks slowly get more and more noticable each time you run the water. And by slow, I mean in a day or two it is back to the worst state like that closeup photo above. It isn’t like the white slowly forms over many months like it did when it was brand new.

Maybe there is some sort of protective coating that is on the sink when they are new that takes many months for the hard water to slowly disinigrate? It did take a while to form the stains from brand new. So maybe once the coating is gone, the white stains become permanant? I don’t know, but that is my theory.

Jazger, please update us with what you hear from Blanco. Maybe they have figured out a solution by now. Since yours is only 8 months, maybe you will be able to save it. I have had my sinks for 5-6 years and I am sure they are beyond help.

Diana and Patricia, yes if I replace them, I will probably go back to SS. That is the only type of sink that I have had over the years that didn’t have any issues.

M Miller, I am so glad you have not had this issue. I know many people like you have not and are still thrilled with their sink. I just want to know why this happens to some of us? Is it the hard water or something else? Doesn’t seem possible we all are using the same harsh chemicals or harshly scrubbing and ruining them all in the exact same way.

(Edited to fix my many typos)