I recently pulled my factory roof rack for inspecting and rust treatment and believe that I may have found a leading reason why the factory rack mounting points often rust out so badly. It looks like water flows in from above and then gets trapped inside the rack feet. See what look like water lines on the inside of each foot in the first picture below for evidence of the water pooling.
It seems like the mixed metals of the roof and rivet nut poorly painted/sealed after install and then soaked in a captive water bath is why these often suffer so much from corrosion.
My roof and the rivet nuts were still serviceable so I ospho coated them and then added sealant to keep water out from above. I also added a drain on each foot to let water out if it does get in there at some point. I may keep the rack long-term since I don't need/want to put much weight up on the roof band I'm optimistic that the rust risk is mostly gone now thanks to the sealing and drains. The following picture shows the drain that I cut with a triangular file.
Anyone else come to this same conclusion or seen similar waterlines inside the feet?
It seems like the mixed metals of the roof and rivet nut poorly painted/sealed after install and then soaked in a captive water bath is why these often suffer so much from corrosion.
My roof and the rivet nuts were still serviceable so I ospho coated them and then added sealant to keep water out from above. I also added a drain on each foot to let water out if it does get in there at some point. I may keep the rack long-term since I don't need/want to put much weight up on the roof band I'm optimistic that the rust risk is mostly gone now thanks to the sealing and drains. The following picture shows the drain that I cut with a triangular file.
Anyone else come to this same conclusion or seen similar waterlines inside the feet?