Door Top Restoration Tip, ...if you ever wondered why they rust Options

[tomeric914]

The top of one of the doors on my "track car" had spots that rusted through. While initially I had POR15'd them, the recent addition of flares was the impetus for me to strip the doors down and paint them as well. Unfortunately, it lends itself to rust due to the galvanic reaction between the aluminum and metal.

Removing the extruded aluminum channels that hold the fuzzy strips and rubber window wipers was a challenge on one side because the screw heads stripped and must have been made from an alien metal that destroys small drill bits. After the screws were extracted, removal of the channel required some finesse to keep it straight especially considering the corrosion that lurked underneath.

The metal fold of the door that the channel slips onto is in such a position that it cannot be properly painted. Using a mirror, I saw surface rust in exactly that spot which explains why rust shows up on the window sill (I POR15’d the rust I saw in the mirror). Further compounding the issue is there are two pieces of metal sandwiched together AND the aluminum extrusion that holds water. Add corrosion to the mix and the channel becomes a wick for moisture to travel from outside to inside.

I Marine Cleaned and Metal Prepped the aluminum channels in an attempt to remove any ferrous rust that had attached itself to the aluminum. Then I filled the channel with grease that slips into the door to prevent future corrosion.

In the cross section below, BLACK is the door, RED is the metal support inside the top of the door and BLUE is the extruded aluminum channel that holds the fuzzy strip and the outer rubber window wiper. I put grease in the blue U shaped area that slips over the black and red.