Anyone know what this is?

[s1000pre]

My 2021 FC bunk has black marks along the top edge of my Corian counter. It doesn’t wipe off with a damp micro-fiber. I don’t want to use anything to abrasive. I don’t think it is mold, I’m a clean freak and good at keeping this area clean. It recently appeared and hope it isn’t some type of corrosion.

[SlowPokePete]

It looks like some sort of adhesive that has attracted dirt to me.

SPP

[NO NOIZE]

I have the same marks, my assessment is that the counter edge is slightly vibrating against the wall while on the road. It has abraded the clear coat in that area and allowed Filiform corrosion to begin.

I applied this: https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

Along the edge of the counter with an eye dropper and wiped off the excess. This will arrest the corrosion that has begun and provide some lubrication qualities to prevent it from getting worse.

As with any product you are unfamiliar with, apply Corrosion X in an inconspicuous area to see the results or if it has any undesirable effects. Then apply to the effected area in a very small spot to start with so you may evaluate the results of the treatment.

Hopefully others will chime in with some other ideas or better news.

Good luck

[SuperTrouper]

No Noize said "my assessment is that the counter edge is slightly vibrating against the wall while on the road."

X2 - Brad

[GammaDog]

Originally Posted by NO NOIZE

I have the same marks, my assessment is that the counter edge is slightly vibrating against the wall while on the road. It has abraded the clear coat in that area and allowed Filiform corrosion to begin.

I’m behind the vibration->abrasion->marks theory. Depending on the year/model, the interior panels are likely stainless, not aluminum. Filiform is specific to aluminum panels coated with a protective layer. If your trailer has stainless interior panels, it’s (fortunately) only abrasion, not corrosion.

[s1000pre]

It’s a 2021 FC 30Bunk. It’s definitely aluminum. I carefully scratched off the black marks using the blunt end of a butter knife. I could feel a slight groove running parallel with the counter edge. This seems to be the tightest point between the counter and wall for the entire length of the counter. I’m going to do my best the break the top edge of the corian in this spot. Unfortunately, the damage has been done and the clear coat has been compromised.