I have put similar streaks on my sinks from my titanium watch/band. And nothing so far removes them; I'm considering a metal polish.
Casey

Try ZUD. Similar to BKF, but maybe different enough to work? I've used it to remove metal marks on my dishes.

Ps use the powder, not the cream/liquid version--I think it packs more punch.

Try Wenol polish, it's the only thing that got use marks off my old Franciscan china plates.

Here is a link that might be useful: Wenol on amazon.com

Hi...have you considered contacting Shaw's? I wonder what they might suggest.

My sink is porcelain, not fireclay, but Comet (the powder, not the liquid) works for me on those grey scratches from metal.

Though using the pumice is pretty simple, I found some instructions on how to clean the marks.

At first, you will think, "Oh no! I've made the marks worse!" But that's just the pumice disintegrating in the water. Don't panic, try it, it works!

Here is a link that might be useful: Using Pumice

While I can't speak to fireclay specifically, I can endorse pumice as well. I have gotten out stains I thought would be there forever in my tub, sink and toilet (we have very mineral-rich, water-heater-destroying water).

Are you sure they're marks and not little nicks? I only ask because I have a fireclay sink with a tiny nick. I consider it patina. ;)

The pumice idea makes me a bit nervous. Pumice is an abrasive like sandpaper. I am not an expert on fireclay, however I would suppose constant cleaning with pumice might erode the finish making the sink more porous in those areas which might cause later staining. Soft Scrub might be a bit less harsh.

Made me nervous too, but NOTHING else (including soft scrub) would get them out. They're gone now, so there's no constant cleaning with the pumice. Thorough internet search on continued use of pumice on fireclay turned up nothing. If anyone knows what longterm use will do, I'd be interested to hear!

I have similar marks in my new fireclay sink. The surface is smooth to the touch, but they vary from light to dark gray...almost like pencil marks. I've tried regular cleaning spray and the magic eraser. I've heard about the pumice stone, but I want to make sure it works without causing further damage. Has anyone else used it on fireclay? Ella_socal, did you end up using it? Any issues? Thanks!

Have you tried a razor blade?

I agree with Rachiele that pumice stone is just too abrasive for the fireclay. I would suggest using either baking soda or Soft Scrub with a soft sponge.

After you get rid of those marks, apply a bit of liquid wax and keep doing that for like once a month to ensure the sink look smooth and nice for years to come.

Tyler

I just used powdered laundry detergent and they came off with no damage to the fireclay and cheaper than buying extra cleaning products :)

One more thought... I have found Mr. Clean Magic Erasers to be quite amazing. That might work too!

I had the same problem with black marks on my Rohl Fireclay sink, until I used Bar Keepers Friend.

We had a Kraus fireclay sink installed about 6 months ago and have numerous marks that I have not had any success removing. They are not scratches. The sink is the Turino in a white matte finish. I purchased it on Amazon for about $900. I read the manufacturers recommendations and have done all of them. I called customer support today to request additional bumpers for the rack that sits in the base, as some of the more noticeable marks are from the rack rubbing against the inside of the sink. The rep agreed to send the racks however had nothing else to recommend for treating the marks. The marks are fine and resemble pencil marks… I am looking for any suggestions you might have that aren’t suggested in this thread. … I may just have to live with it as I don’t feel replacing the sink is an option.

Meant to add a picture. You will probably need to zoom in.

Not sure about fire clay but Barkeepers friend works great on every stain in a porcelain sink.
Also, leaving comet wet on the spots overnight might work.

Also we leave the bar keepers friend sprinkled in our sink overnight. Works magic. BUT i think it was responsible for removing the finish on the drain… went from aged Bronze to coppery. Doesn’t bother me.

Just a thought... there might be a tendency to try bleach. Just guessing here, bleach might etch the surface and cause stains to be caused more frequently.

Also we leave the bar keepers friend sprinkled in our sink overnight. Works magic.

Never do this. This was irresponsible advice. It will take off the finish of your sink - any material - and of course your drain flange. The label of BarKeepers Friend has instructions in boldface large type that it must be rinsed off within 1 minute of application. There have been posts on this forum from people who ignored the label's directions and ruined their sink.