mystery leak found

[GWMattson]

I've been chasing down a mystery leak in my front window for about a month now. Today, I think I finally found the source. There is a rail for a rock guard/awning on top of the window. When I took this apart, I found some very rusty through bolts. They were sealed on the inside of the camper, and I think this sealant was leaking on at least one bolt. I just bought some stainless bolts to replace them. My question is: what is the best way to seal through bolts? My first thought is to put some butyl caulk on the threads (or in the hole), and also try to put some kind of sealer on the bolt head outside. I'm not sure what to use on the bolt head though. Any ideas?

[Dave Fish]

I just fixed, I hope, a similar problem. I have 4 quarter inch bolts holding the solar panels. They come through the top of the roof with a large gasket on the inside but only silicone sealer around the threads on the top side. There is about 3/4" spacing between the roof and the plate that holds the solar panels.

Solution: I added a rubber gasket + regular washer + a nut to seal the bolt to the roof. The rubber gasket is about 1/16" thick with a 1/4" whole matching the bolt. I found the gasket washers at the local Ace hardware.

This pasted the water hose test. We'll see if it passes the rain test when we take it out for a short trip tomorrow since it is supposed to rain part of the time.

[GWMattson]

Originally Posted by Dave Fish

I just fixed, I hope, a similar problem. I have 4 quarter inch bolts holding the solar panels. They come through the top of the roof with a large gasket on the inside but only silicone sealer around the threads on the top side. There is about 3/4" spacing between the roof and the plate that holds the solar panels.

Solution: I added a rubber gasket + regular washer + a nut to seal the bolt to the roof. The rubber gasket is about 1/16" thick with a 1/4" whole matching the bolt. I found the gasket washers at the local Ace hardware.

This pasted the water hose test. We'll see if it passes the rain test when we take it out for a short trip tomorrow since it is supposed to rain part of the time.

Good idea. I think I'll try it.

[BraddyMac]

We are restoring a 1981 Trillium 5500. It amazes me to find damage caused by folks who just don't get it (previous/original/former owners) Things like curtain rods put up using screws longer than the depth of the frame (poked out through the fiberglass) A hook for a fly swatter up beside the door with a screw at least an inch long, with much of it protruding outside of the trailer...belly band screws removed with rivets placed alongside of the original holes. Most of the holes were left uncovered. Caulking around the belly band that had come away from the shell. Jeeze! Can you guess where the leaks are?? (In all of those places) Oh, and let's not bother to seal the marker lights after replacing them with smaller ones that don't even cover the wiring...

[Joe MacDonald]

I have been able to keep my original marker lights by buying new lenses online, I just got a complete set +1 because I lost one orange lens last trip out, and figured I should have a complete replacement set. The lights are a standard 2x4 marker light, but the particular brand is Miro flex, still available at rvshop.com
Bases and lenses

[GWMattson]

Originally Posted by BraddyMac

We are restoring a 1981 Trillium 5500. It amazes me to find damage caused by folks who just don't get it (previous/original/former owners) Things like curtain rods put up using screws longer than the depth of the frame (poked out through the fiberglass) A hook for a fly swatter up beside the door with a screw at least an inch long, with much of it protruding outside of the trailer...belly band screws removed with rivets placed alongside of the original holes. Most of the holes were left uncovered. Caulking around the belly band that had come away from the shell. Jeeze! Can you guess where the leaks are?? (In all of those places) Oh, and let's not bother to seal the marker lights after replacing them with smaller ones that don't even cover the wiring...

I guess I had it better than you. I bought my Burro from somebody who knew what he was doing. I think he fixed most of the problems. But I still find a few, like this leak. Good luck with your Trillium. If the shell is good, you can fix everything else. Just remember, belt and suspenders are good for any hole in the shell. Make sure that it won't leak with 70 mph winds and lots of vibration while the trailer is going down the highway.

[k corbin]

I do put butyl rubber tape on all the threads that go into the trailer shell. The excess will squeeze out forming an additional gasket under screw and bolt heads and washers and nuts.


I taught this trick to my friend who has lived full time on a sailboat for 30+ years and he has now adapted it as his standard practice. Now more pesky leaks!

[Nicolas]

Isn’t amazing what butyl can do!!!! I’ve done an almost complete re-bolt of my ‘78 Boler and have used a ring of butyl tape around the bolt heads to form a seal. That plus the extra cost of stainless steel will hopefully ensure water tightness plus the absence of rust streaks.

I agree with with the wonderment of a previous commenter about what some people do to create their own leaks. My Boler was a misused hunt camp bunk substitute that had all sorts of holes drilled into it for hanging stuff (All done with little thought to sealing. And in the cases where the sealing became an issue, the leak was solved by a truly messy caulking job (in some cases with no regard to matching the “decor”. Dark brown caulk on the white upper fibreglass shell!)

[BraddyMac]

Ummmm belt and suspenders? Do tell.

[Rnupnorthbrrr]

When you all replace rivets with stainless steel bolts how are you sure of the size to use and what are you using for the cap on the head of the bolt (on the outside of the camper) ?
Thanks

[GWMattson]

Originally Posted by Rnupnorthbrrr

When you all replace rivets with stainless steel bolts how are you sure of the size to use and what are you using for the cap on the head of the bolt (on the outside of the camper) ?
Thanks

I used a bolt with a slightly bigger diameter than the ones I removed to get a tight seal. The head had a flat bottom, and I used a washer between it and the neoprene washer. The thought crossed my mind to leave out the rubber washer and use a flexible glue, such as shoe goo or flexiglue, over the screw head. I'm not sure what will last longer - a neoprene washer or the flexible glue.

[Dave Fish]

Originally Posted by Dave Fish

I just fixed, I hope, a similar problem. I have 4 quarter inch bolts holding the solar panels. They come through the top of the roof with a large gasket on the inside but only silicone sealer around the threads on the top side. There is about 3/4" spacing between the roof and the plate that holds the solar panels.

Solution: I added a rubber gasket + regular washer + a nut to seal the bolt to the roof. The rubber gasket is about 1/16" thick with a 1/4" whole matching the bolt. I found the gasket washers at the local Ace hardware.

This pasted the water hose test. We'll see if it passes the rain test when we take it out for a short trip tomorrow since it is supposed to rain part of the time.

Update: The repair also passed the rain test. We towed about 400 miles with one overnight in off and on rain during the drive and over night. No leaks.

Some of the other solutions look pretty effective as well depending on the situation.

[Rscotta]

Try using sikaflex. I work at a company that makes fibreglass water tanks and that's what we use.

[GWMattson]

OK, the mystery leak wasn't found when I first posted this. It leaked again. I cleaned up all the adhesive and insulation above the window and found out that there was another leak in the seam between the two halves of the shell. I think that they did this when they attached the rock guard. They cut the seam to get a flush mount for the rail that the rock guard mounts to. But they never fiberglassed over the crack. There was lots of silicon here that I removed and replaced with butyl rubber caulk.
The rail mount is flexible which makes sealing a challenge. I think the real solution is to remove the rail, fiberglass over where the seam was cut, and then come up with a solid way to mount the rail. I'll wait an see how my caulk job does. If it leaks again, I'll try this. For now, everything is leak free.

[Mike_L]

Stainless is definitely the way to go, strong and no corrosion.
Where possible I use a bolt and a nut instead of a screw.

Depending on the integrity of the original holes I sometimes drill them slightly larger if the fiberglass is compromised and I'm using a nut and bolt. I sometimes use an epoxy to fill the original hole if I'm using screws however it may be difficult to remove them should you need to later.
Whether screws of bolts, use ones with flat (underneath) heads. The wider the head the stronger the union.
I use faucet washers from the hardware store to seal against leaks. They are sturdy, durable and cheap.
Place a stainless flat washer, the same diameter as the faucet washer, over the head of the screw or bolt and then the faucet washer.
Don't over tighten to distort the washer.
Caulking doesn't always work well under pressure although I have used it. Before tightening the screw or bolt head all the way in put a drop of caulking on the shaft and screw it in until the drop of caulking fills the space between the head of the bolt or screw and the material it is being screwed into but don't tighten it completely or all the caulking will squeeze out. When the caulking has set tighten in the screw or bolt the final turn. In effect, you are making a soft washer to seal out moisture.
Screws or bolts with faucet washers won't leak, even under pressure. Half the homes in the country still use them in their taps.