Steve,
Where are these holes? You mention rolled edges -- not too familiar with
your trailer so please explain in further detail if possible. If you have
pictures please send them to me off list at my Email address listed in the
From: line above.
Rounded or radiused corners are done so that you don't have points on the
corners of aluminum sheetmetal which actually is a stressed part of the
metal. A radius allows for any stresses to be spread out along the entire
edge of the repair metal. You should also not have any sharp corners in the
old metal you are repairing. If you have cracks in the metal you should use
a "stop drill hole" -- simply drill a decent sized hole at the end of the
crack line to once again, spread out any stresses to the rest of the
sheetmetal.
I'd be happy to talk a look at what you are doing if you can send me some
pictures. You will need to seal the inside edge of the patch plus you will
need to put sealant into the drilled rivet holes you make prior to placing
the pop rivets in your repair.
If I'm not mistaken the belly skin is made of very pliable aluminum -- so
that it can stretch if hit by rocks and road debris I would imagine without
cracking. You should be replacing the sheetmetal with at least as thick or
at least as strong or stronger metal also.
Tom
WBCCI 5303