patching holes in the roof, am I doing it right?

[Brian Schulz]

Now most normal people would post a thread BEFORE they made a major repair but I suppose now is better than never.

Just added a marine hatch to the rear roof of my argosy which is a story in and of itself. But for my question specifically:

Where the .032 6061 sheet flashing meets the hole in the trailer roof,
I cleaned both surfaces,
overlapped the sheet by 1 inch,
drilled the sheet at 1 1/4 spacing 1/2 inch in from the edge,
put butyl putty tape on the underside of the flashing 1/8 inch in from the edge,
pressed it onto the trailer,
drilled through the existing holes and the putty into the trailer skin,
set olympic rivets,
then sealed the perimeter with 3M 5200

I've got 5 more holes to do, including the monster one where the air conditioner was, does that process sound about right?

[Belegedhel]

I'm not sure what the 3M 5200 sealant is, but assuming it is some kind of poly or butyl sealant that remains flexible after curing, it is probably fine.

The only thing I would recommend with your process is to remove any little o-ring gaskets that might be on the Olympic rivets, and to coat each rivet in sealant before putting it in the hole and setting it. Otherwise, looks like a sound process.

good luck!

[truckasaurus]

I might be missing it in the description but after you drill holes you should always deburr the holes before final assembly. So just to recap, drill everything, deburr, clean, add whatever sealant you like, reassemble and fasten. By deburring the holes you allow the rives to sit flat which in this case reduces the likelihood of leaking to a later time :-)

As an added step if you drill off using a smaller drill bit then upsize to your finished size it should all line up better too.