'76 Trillium-Not All Leaks From Bellyband

[georgewa]

Just finished fixing all our Trilly's leaks and learned that they all cannot be blamed on the leaks from the belly band.

Yes, the belly band was leaking, but there were also leaks from around the frame of a window, holes in the side of the Trilly, from rivets in the awning strip, from screws of the door (from down dripping water), etc. The other sources of leaks were discovered after the belly band was caulked and leaks persisted. Good thing I didn't attempt to solve the leak problems by removing the belly band and fiberglassing the gap.

The rubber strips and weather stripping of the top edge of the belly band did not seem to fix the leaks, so I went to caulking the top edge of the bellyband with Sika 295-UV ( low strength polyurethane) used for windows on boats.

The holes in the fiberglass walls were plugged with Pro glass fiberglass filler or West Systems G/flex epoxy.

Rivets and screws were plugged with Capt. Tolleys Crack Cure and Parr Parabond clear.

Window frame edges were sealed with ProFlex clear caulking.

Holes in the avocado green interior were painted with Behr Ultra Natchez Moss which perfectly matched the color but not the original glossy finish.

One of the advantages of living in the Pacific NW is that it acts like a laboratory for your trailer to test it for leaks; there is no need to drive to a leak testing center like the Airstreams frequent.

All the caulking jobs required hrs of prep time, cleaning with isopropyl alcohol repeatedly, using other recommended activators and primers, taping with 3M low adhesive painter's tape, using a good quality caulk gun, making sure the caulk was not cold, having an assistant to put pressure on the caulk bead while you caulk, then pull the tape ASAP.

Also, be aware that caulks and primers all have shelf lives; caulk expires typically in 12 mos, so be sure to check the date on the tube. It was possible to caulk the entire 30' belly band top edge with 1 18oz tube of caulk, but a second tube was available if needed.

Hope this helps. Good luck!

[georgewa]

While on the subject of plugging leaks in the Trillium, forgot to mention that there are some holes in the body of the Trillium that are your friends and should not be plugged.

Being a newbie, I learned this the hard way after plugging a hole in the floor near the wheelwell under the dining room seat . One day we were wondering why there was such humidity in the Trilly, only to discover 3" of water in the underseat storage compartment because the drain hole had been plugged. The floor holes were essential for letting water drain out from leaks above the floor.

The Trillium veterans undoubtedly know all about this kind of stuff but when you are a newbie and your used Trilly doesn't exactly come with a user's manual, mistakes are bound to happen.

Even if you are familiar with what the floor holes are there for and know enough to not plug them, you might not realize that the holes are not always in the right places, ie the true lowest points in the floor where water gravitates to so it doesn't pool and can drain out. With all the water coming in at times after rain storms, we did end up drilling a couple extra holes so water could drain out easily.

We are out on our first trip of the new year on the Pacific coast right now. It rained just before we left and a leak appeared under the roof vent over the refrig. Some areas around the corners of the roof vent and two screw holes were caulked before we left.

It suddenly rained all last night and I am happy to report that we were leak free. All this work paid off. As one person said on the Airstream forum - "You don't know if you're having leaks if you don't check for them ". My wife gets the credit for spotting the leaks which isn't always easy when the Trilly is all loaded up. I have to admit I was none too happy to have to deal with another leak when we thought our problems were cured after the previous leak fix. That's a good reason to bring some caulking material with you when you travel, just in case, as another forum member suggested.

Best wishes for leak free travels!

[Roy in TO]

Originally Posted by georgewa

One of the advantages of living in the Pacific NW is that it acts like a laboratory for your trailer to test it for leaks; there is no need to drive to a leak testing center like the Airstreams frequent.

Ahh, I like your sense of humour!

I missed this thread the first time around, I'm happy you added to it. Loads of great information! Thanks.

[Tyhee]

Lol
This almost should be a stickie. X100 on prep time importance.
Good job! Pretty sure I lost a good amount of fingertips participating in similar leaks quest. And I did not tackle my windows yet!
Curious did you pull your windows or just thoroughly prep around them and caulk? I'm leaning to the latter....in fact starting in an hr...lol
All you shared is great info thanks. Don't forget the respirator too!

[Tyhee]

Well I did not start my windows as planned because I decided on (what I thought ) a quick job of replacing a tail light bulb. As result, I spent most of the day cleaning and resealing these lights and the rear side markers. On closer look under dinette seats it looks like most we're leaking for a long time. I used silicone on this application and siliconed the housings to the trailer (with bolts too) then the lenses to the housings also. Made sure to check both bulbs were fully operational before sealing them up though.
I changed both bulbs with high quality replacements and used stainless fasteners where possible.

[georgewa]

Thank you both for your positive reviews.

In answer to the window caulking question, yes the caulking was done with the windows in. The black plastic edge strips were removed and cleaned. The window edges were thoroughly cleaned for hrs with paper towels, a credit card plastic edge and isopropyl alcohol until the paper towel passing in one direction was clean. Old superficial caulking at the top and bottom corners was removed.The window edges and Trilly wall were taped off so only about 1/8" space remained to receive caulk ( so as to interfere with getting the black strips back on). The caulking (Flexseal clear) was applied by one person, then a 2nd person applied pressure on the bead, then almost immediately, the tapes were carefully pulled on that side. Capt Tolleys Crack Cure was applied to all the screws, then clear caulking (Permabond). All the plastic strips were able to fit back on the windows edges without difficulty ( a worry if too much caulking had been applied) and two holes in these strips were repaired with strips of plastic inside and crazy glue with a dab of black Magic marker to match the color.

After reading about different caulks for what seemed like months, I stuck with non-silicone caulks because I was worried that silicone would not last long and silicone contaminants would make redoing the job more difficult later on, as nothing would stick to the surface. Also, silicone caulks have a bad rap for use on rvs, but I have to admit that the Airstream folks use silicone for their windows (a neutral silicone cauk and they sell it on their website).

One thing to keep in mind is that there are two basic kinds of silicone caulk, one is acidic and the other is neutral. When using silicone around metal, particularly aluminum, one wants to be sure to use a neutral silicone if one is going to use silicone, as the acid type can interact unfavorably with the adjacent metal.

One has to be careful taking advice from people, even supposed experts at rv repair shops, who are supposed to know all about caulks. One fellow at a rv dealership swore by a certain silicone caulk for caulking rvs because he could easily remove it and was resigned to the fact that one should anticipate having to recaulk every 1-3 yrs. ( for which he was getting $90/hr to do he admitted ). He recommended a certain brand of silicone caulk which I purchased only to discover later that it was an acidic silicone caulk. Fortunately, I never used it for the reasons mentioned ( after researching it later).

Also, keep in mind when caulking that you can go to the other extreme, ie use a high tensile strength polyurethane that would be impossible to remove like the 3M 5500 caulk which has on its label "permanent" bond. Other forum members have also warned about this.

That is why I used the low tensile strength polyurethane Silka 295 UV for the sealing of the top edge of the belly band. It remains to be seen how the caulking job holds up. All I can say is that I did the very best I could prepping it ( half a day+) with the intention of having it lasting a lifetime. I will definitely let everyone know if it fails so others are aware of its shortcomings as a choice for sealing the belly band.

Good luck ! And it doesn't hurt to do your homework .

[georgewa]

Noticed two typos in the last post.

The 3M permanent adhesive/caulk is named 5200 not 5500.

The caulk around the windows was applied thin so it would NOT interfere with putting the window plastic edge cover strips back in.

Sorry for the errors.

[David Tilston]

Walter, you may have noticed an "Edit" button beside the "Quote" button in your recent posts. This allows you to change typos for about 24 Hrs after you make a post.

[georgewa]

David,

Thank you for the suggestion to use the edit option.

I did start the edit process, and when it asked "why are you editing", I bailed out wondering what road I was headed for. I will persist the next time.

[David Tilston]

I have stopped answering that question. It still works.