How to seal original vent

[Ian]

Hey gang,

The original vent on our '66 Compact is leaking somewhere, and the top of the trailer is a mess. Someone has obviously tried to reseal it at some point.

I want to get up there and scrape all the crap off the roof and reseal it properly. But I haven't found a good detailed description of how to seal the vent, other than using butyl tape as well as silicone.

Can anybody provide a detailed description of where to use the tape, vs. the silicone?

My thinking is to lay a bead of butyl around the opening, install the vent, then seal the outer edge with silicone as well as the screws.

Any other thoughts or tips? I want to seal this up before the rain hits again this fall here in Portland.

Thanks!
Ian

[vikx]

Remove the vent and clean the metal and vent flange well. While the vent is out, check the framing and raise the vent square a little higher if possible. (shim with 1/4" plywood or..) RV putty tape goes on the vent flange before installation. Screw the vent into (new, if necessary) wood framing. Dicor self leveling lap sealant is a caulk that will seal the vent well. It is like liquid bubble gum. At least one tube per vent, sometimes another half.

Silicone is never recommended for our vintage trailers. It tends to fail quickly, turns dark and ugly and peels when least expected. I like the way it smooths out but in the end, it is not worth using.

You might try a wire wheel on the roof coating. Once clean, it should not need re-coating, which can cause metal rot if compromised. In other words, less is more. Coatings generally crack and allow water to creep everywhere. You can't see areas needing repair with a thick coat of Silver Slop, Snow Snot or Kool Krud.

Proflex in the CAN is a paint on sealant that really does work and seals iffy roof areas. It is not meant for vents but maybe a seam or crack. 2-3 coats work wonders. I sometimes use a very light coat on the top of the edge trim.

Hope this helps.

[Ian]

Great info, thanks!

Ian

[Ian]

OK, I found the Dicor locally, will pick it up tomorrow. As for raising it, do you recommend adding the 1/4" plywood just under the roof skin, to create a slope for the water to run off?