Corian sinks--need advice! Asap! Please!
About 18 months ago, 3 custom made Corian sinks were installed in my bathrooms. I noticed immediately that all 3 sinks have a seam, inside the bowls, and on the outer lower edge on the countertops. After a few days, the seams turned yellow. The installer sanded the area, and the yellow went away, but the seam was still there. It wasn't as wide as before, but you could see a straight line from one end to the other.
The installer replaced one of the sinks. Same problem! He came to the conclusion that my water must be too hard and causing this problem. The hard water test came out fine. A Dupont representative came and saw the lines. After many emails, I realized the rep is incompetent. All she did was take photos and sent it to other representatives, and get their opinions. I never saw the photos, so I'm not sure how clear and visible the seams were.
To make this long story short, the installer and this rep now claim the yellowing and seams are from cleaning products. I use soft scrub and wipe up any standing water.
My parents have Corian sinks, installed by Home Depot 15 years ago. They have no seams at all. I've never seen a Corian sink that have these seams.
I'm at a loss as to what to do. Has this happened to anyone? Any advice??