'76 Trillium Belly Band Leak Fix

[georgewa]

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!

Hopefully, 100

[David Tilston]

Originally Posted by georgewa

Some outside specialists have questioned the resultant road flexibility and strength at the seam if the fiberglassing could not include interior fiberglassing.

Your outside specialists simply don't understand the situation. When the two half's of the trailer are joined, they are lined up and the belly band is installed by riveting through the belly band to the metal plates that are on the inside of the trailer. The corners often use multiple stacked plates spaced quite close together. I assume that the stresses involved in lining up the corners are significantly higher then on the sides. After the belly band is in place, they ran a fiberglass bandage on the inside. Even when the belly band is removed, and the metal plates are removed, the bandage is still in place. Filling in the resulting gap with fibreglass, makes the belly band the thickest fibreglass on the trailer. Pictures of the process can be found in several threads. Maybe show your outside specialist this thread:
http://www.fiberglassrv.com/forums/f...ead-59580.html

As far as I can see, this makes the trailer stronger then when it had a belly band.

BTW: Feel free to add your Trillium to the serial number list:
http://www.fiberglassrv.com/forums/f...tml#post451605

[georgewa]

David,

Thank you for your comments re strength and flexibility at the fiberglassed seam, and posting the link for your 2nd thread on fiberglassing. I had missed the latter.

If I were to go the fiberglassing route, your threads would prove invaluable. Also, I would wish you were in business to do it and close by, as you have so much experience with this.

[David Tilston]

I have only done two, I still have four, (five?) more to go.

[Night Sailor]

Originally Posted by David Tilston

I have only done two, I still have four, (five?) more to go.

Thanks for sharing that link. Impressive repair.

If I didn't want to do a similar repair I'd try to swap campers with cash for one that had this already done.

[Night Sailor]

Originally Posted by georgewa

David,

Thank you for your comments re strength and flexibility at the fiberglassed seam, and posting the link for your 2nd thread on fiberglassing. I had missed the latter.

If I were to go the fiberglassing route, your threads would prove invaluable. Also, I would wish you were in business to do it and close by, as you have so much experience with this.

Any auto body shop could do this. It is similar to bonding fiberglass on a Corvette

[Night Sailor]

Or try a boat yard.