Warning about a roof top storage box
Hey everyone. I am about done with my cabover rebuild and want to share something that I think is important about a roof top storage box.
I removed the storage box to work on the roof and I had not intended on putting it back up there. That meant I had 6 lag bolt holes to patch.
The 3 mounting holes furthest back are on the upper slope of the roof. I used a blade to remove all the silicone caulk someone gooped on there, then sanded the aluminum clean and put Eternabond patches over the holes. I am confident that will be nice and water tight.
However, the three holes on the lower part of the slope had a fair amount of corrosion around them and would require a bigger piece of Eternabond to seal them. I was fine with that, but as I sanded off the oxidation and muck around the big holes I realized there were a bunch of pinholes all over that area of the aluminum roof. Looking closely at everything, I realized that trapped dirt and water under the lower edge of the damned box caused galvanic corrosion all over the place. There is basically a 12" or so strip across that lowest area of the aluminum roof (where the box would have trapped all the moisture) that is pockmarked with pinholes.
Aluminum roof's are supposed to be just about maintenance free. What this shows me is that roof top boxes are a BAD IDEA!! Now I have to fix not just 6 big holes, but do a larger scale repair of that entire forward section of the roof.
My plan is to use some 6" wide u seal tape laid in an overlapping pattern and leave a 2" outer edge. That will cover the area like a super sticky aluminum "patch". I will then cover the seams of the large patch with my leftover Eternabond and I will also seal the edges with Eternabond. I will post pics to this thread when I am done.
Jose
I removed the storage box to work on the roof and I had not intended on putting it back up there. That meant I had 6 lag bolt holes to patch.
The 3 mounting holes furthest back are on the upper slope of the roof. I used a blade to remove all the silicone caulk someone gooped on there, then sanded the aluminum clean and put Eternabond patches over the holes. I am confident that will be nice and water tight.
However, the three holes on the lower part of the slope had a fair amount of corrosion around them and would require a bigger piece of Eternabond to seal them. I was fine with that, but as I sanded off the oxidation and muck around the big holes I realized there were a bunch of pinholes all over that area of the aluminum roof. Looking closely at everything, I realized that trapped dirt and water under the lower edge of the damned box caused galvanic corrosion all over the place. There is basically a 12" or so strip across that lowest area of the aluminum roof (where the box would have trapped all the moisture) that is pockmarked with pinholes.
Aluminum roof's are supposed to be just about maintenance free. What this shows me is that roof top boxes are a BAD IDEA!! Now I have to fix not just 6 big holes, but do a larger scale repair of that entire forward section of the roof.
My plan is to use some 6" wide u seal tape laid in an overlapping pattern and leave a 2" outer edge. That will cover the area like a super sticky aluminum "patch". I will then cover the seams of the large patch with my leftover Eternabond and I will also seal the edges with Eternabond. I will post pics to this thread when I am done.
Jose
