Five Years Later, BOK Center Is Still A Hit

[Vision 2025]

I recall that the blame for the staining was placed on the use of the wrong appoxy in the joints between the panels and that it was supposed to be changed out at some point.  It's been a while, so that is relying on a foggy memory.

Actually, I believe the majority of the staining is primarily caused by the silicon used in the window glazing weeping. 

[Hoss]

Actually, I believe the majority of the staining is primarily caused by the silicon used in the window glazing weeping. 

I also know that some engineers also said another reason for the streaking/staining was due to dust that would build up in the joints and run as it rained.

[Gaspar]

Actually, I believe the majority of the staining is primarily caused by the silicon used in the window glazing weeping. 

More likely bi-metalic galvanic corrosion.  The contact between two seporate metals (i.e. stainless and aluminum).  In the presence of an electrolyte created by rainwater, and city air, the window frames and steel skin exchange ions over the calk and in direct contact with each other. Concentrated aluminum oxide (and other oxide) residue dripping down.  Can also take place at welds where differing metals are joined.

Normal.  Nothing you can do about it. Arch has it too.

[Conan71]

More likely bi-metalic galvanic corrosion.  The contact between two seporate metals (i.e. stainless and aluminum).  In the presence of an electrolyte created by rainwater, and city air, the window frames and steel skin exchange ions over the calk and in direct contact with each other. Concentrated aluminum oxide (and other oxide) residue dripping down.  Can also take place at welds where differing metals are joined.

Normal.  Nothing you can do about it. Arch has it too.

Actually there is, dielectric unions but that's a discussion for another day.  At least that's what you do in piping and plumbing to prevent it.  May be different with structural materials.