possible defect?

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possible defect?

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You might try putting a little heat to the panel, such as from a lighter held to the bottom side of the metal, and see if the stripe dissipates. In any event, you should discuss this with your contractor / supplier and see what they say. This is not something you'd normally expect to see.

Todd Miller
2023-03-19 15:06:07.721786

I am sorry. I really can't diagnose from these photos Perhaps someone else can. My only thought was some sort of burnishing of the clear coat which could possibly evaporate with heat. I doubt it's from the rollforming process but was likely on the coil before it was formed. It is highly unusual patterning for any sort of corrosion.

Todd Miller
2023-03-19 15:40:21.452719

As Todd mentioned, hard to determine the root cause from the photo. The lines could be from the mill or the roll former. It does not look like white rust, as it is very linear and consistent. In my experience rust will meander. As for the difference in the water beading, what is the time difference of install between the old and new panels?

Philip Thompson
2023-03-20 14:13:56.234353

hi guys,
i’m having a metal roof installed here in florida. i’ve noticed these streaks running lengthwise on a lot of the panels. the darker panels were ordered last. wondering if i should have them replaced, but i’m not sure which direction to go with. any insight would be greatly appreciated.
thanks!61DF7A70-9DED-45C7-8CD7-F569B34F0EE2.jpeguploading A627C3DB-5C03-484B-BF2C-CF38D469E0C4.jpeg

J S
2023-03-19 14:46:45.614652

Unfortunately I can't try to heat the underside. Panels already installed. Just curious as to if you guys think this defect was on the coil before rolling, or possibly a dirty or damaged roller. Also wondering if it's going to cause abnormal wear or premature falling of the finish. Possible white rust from storage?

J S
2023-03-19 15:32:49.935210

Agreed. Thanks for the insight!

J S
2023-03-19 15:43:28.022355

also, i noticed after the rain today that the darker colored panels are somewhat hydrophobic and water repellent. the lighter colored panels seem to pool water differently. in this pic the new darker colored are on the right. i’m wondering if i accidentally received 2 different products. maybe the left is “paint ready” and the right has a clear coat?
49C7715C-308A-404D-8C13-71D5F50CA54B.jpeg

J S
2023-03-19 22:30:20.243581