Good morning,

05 super cab w sun roof, 5.4, 151k. Starting to see some rust on cab corners. Just thinking, Has anyone drilled a weep hole in the corners to drain water out?? When drained, spraying fluid film or other product through the hole to slow down rust growth... any thoughts??

Bernie

 

sounds like a reasonable plan. I had a 94 f150 and it had some horrible spray foam in there factory that would trap any water in there like a sponge and make the cab corners on the super cab rot terribly.
I think if you can find where water is intruding and prevent that from happening it will further the cause. And then yes try some of that spray wax or some such coating to slow the spread.

 

When I had my cab corners done they drilled some some holes in the cab to drain the water. Its been almost 4yrs still looks good