We have owned our '76 Trillium
1300 one year now and park it outside and have just discovered how in deed the belly band leaks
, all around. Thanks go to all on this forum who have contributed to helping owners fix this problem.
Yes, I could remove the belly band by drilling out the rivets and fiberglassing over the gap, then paint/tape a stripe, but that would be a major undertaking, and would be considered a last resort. Some outside specialists have questioned the resultant road flexibility and strength at the seam if the fiberglassing could not include interior fiberglassing.
Yes, I could caulk the top of the belly band with Sika 295 UV, a low strength polyurethane, but it might not last forever, and would be very difficult to redo since the only method of removing it after it sets is by scraping it off. I did not want to use a silicone caulk as it would not last long and the impurities left behind when it was removed would make fiberglassing and reapplication of caulk difficult.
So, I elected to try using the "gasket approach", sliding different thicknesses of rubber (1/64, 1/32, 1/16") in the space between the top of the belly band and sidewall of the Trilly. This helped solve 75% of the leaks
Not satisfied, Frost Kind Tubular Vinyl Gasket 1/2" wide was tried with and without rubber strips; the latter worked considerably better and only one leak was detected after our most recent Pacific NW rainstorm a day ago, rating this result 90%. So there is still some work to be done.
It was possible to re-rivet the belly band back where rivets had broken using 3/16" rivets and gun from Harbor Freight , but drilling out the back plate is tricky and it is easy to puncture the fiberglass covering of the plate.Fortunately, the area was not visible and I caulked the hole and rivet before fastening it.
The pictures posted will show the gasket in place, trimmed where there was no gap for it to fit inside the belly band, and it looks pretty good if I say so. The gasket on the rear of the Trilly was not trimmed on its lower half, rubber strips were combined with it and it is still a work in progress to cure a leak in one spot.
It should also be mentioned that Capt. Tolley's Crack Cure was used to seal all the rivet heads, the windows
were checked to make sure they were not leaking, and the floor storage bins were checked to make sure their drain holes were in the best positions.
In retrospect, we Trilly owners should not feel singled out for leaks
, as the Airstream folks get the leak fix crown with all their rivets and plates to seal and have funny quotes on their forums, like "You say you have no leaks; you just haven't found it yet!"
My goal is to be 100% leak free. Hope this helps!