I just purchased a new fully clad tri-ply saucepan. Close examination revealed a poorly finished rim. It is slightly rough in spots, which is no big deal, I chalked that up to less-than-perfect polishing.
What did concern me is that it is quite easy to see the individual layers of steel and aluminum. The easiest way to describe it is to say the aluminum doesn't have a bright finish and it looks like the rim has two dark gray pinstripes running the circumference of the rim, where the aluminum meets the steel. I apologize for not posting a photo, but my wimpy camera wouldn't capture the close-up properly.
My question is - is this simply an imperfect polishing job or does it foreshadow possible future delamination or deterioration? I ask because another new pan has a fully polished rim; the pan has to tilted at just the right angle to see that there are three layers.
A related question - Is aluminum not corrosion-resistant? I checked my current older clad cookware rim and found that the aluminum layer is clearly visible, looks dull, corroded (like zincs on a boat's outboard drives, for those familiar with boats), pitted, dinged in places, and generally degraded. It is also no longer even with the steel; running a finger over the rim, it feels (and looks) like the steel sticks out a tiny bit, indicating the aluminum has receded. I've had most of my pans for 11 years. Is this simply the nature of tri-ply construction? Can hand-washing prevent it?
Additionally, I had a lid handle fall off this week and saw that all the lid handles show a greater or lesser degree of corrosion on the screws. The handle that fell off is one on of my most-often used pans, and it is 11 years old. But still, this was a surprise to me. Oddly, the screw heads (which are on the underside of the lids) are stainless and in perfect condition, but the body of the screw is aluminum. Likewise with the rivets holding the pan handle to the body of the pan. The rivet heads inside the pan are stainless, the rivet body itself is not.