Screws Rivets or Varethane Adhesive for Vent Caps and Roof Jacks?

[Datta]

Okay Air Forum Folks,

I am preparing to attach new vent caps for the Refrigerator and Heater Flues and the roof jacks for the kitchen and bathroom.

From my research, Sikaflex 715 is the best sealant out there, so I've got that part covered, but now I'm wondering about the best way to fasten the new plastic parts to the roof: In pulling them off, the old refrigerator flue cover was attached with rivets, while the Heater vent cover used screws, but there's a good chance neither was original equipment.

Anyone out there know how they were originally attached back in 1968? And what about the plumbing roof jacks? A friend of mine recommended considering just using a high-grade varethane adhesive like they do for car windshields...

Standing by,
D

[carver 1]

Butyl Tape. Been using for years for bedding on my sailboat.

>>ron<<

[lewster]

I would NOT stick them down in case you ever want to remove them. Place a layer of butyl tape on the entire underside of the hood, then use stainless steel drill-point sheet metal screws. Put the 715 over the seam and the screws and you're done.

Be careful with the 715. It is indeed great stuff (I use it by the case) but it takes quite a while to set.

Another option (if you will not be removing them any time soon) is to use 3M VHB tape and NO SCREWS. I use this method for solar panel mounting on metal (Airstream) roofs and it works flawlessly. You will still need the 715 over the edge seam to prevent water incursion on the tape.