Stained Corian in cockpit wet bar

If you haven’t already, I’d try granite sealer… the stuff in the spray bottle that’s more like an oily cleaning product than an actual “sealer”.

 

You can sand them out by hand in the sink if it is actually corian, start with 100 grit till stain is gone and keep going finer till you get the shine u want. The color is all the way thru with corian.

 

Is it those rings? What caused the stain?

You could try something with oxalic acid or even hydrochloric acid if the staining is from hard water/minerals.

 

Start with some compound and a regular buffer first. If still there then 1000 grit on an orbital wet sand, compound then polish.

 

One thing on boat counter tops, not all of the ones that look like Corian but sometimes painted and not Corian at all. A friend had a 4460 Regal that had the cockpit bar and it looked exactly like Corian. He got a stain and tried sanding and found that it was painted and not Corian at all.

Find a test spot to sand and see if it is painted or not. But as @ocgrant mentioned, start with a stiff cut compound, but if that doesn't work. Start with ~320 wet sand paper and work your way up to 600-800 then compound.

 

The rings I can get out. The dark areas, what might have cause the stain?