Class C overhead movement causing seal failure

[Juzaxadar]

I'm posting a couple of pics of the corners of my overhead bed.

This is a 2000 Winnebago Minnie 31C.

During a recent 5500 mile trip, I saw a lot of flex happening above the cab. When I got back, I noticed that the corner seal has come loose. I had sealed it with ProFlex about a month before taking the trip, so I know it was good.

The corner (temporarily re-sealed today)


Any ideas about how to limit the flexing or to seal it so that the flexing doesn't break the seal? I can re-seal over and over without much effort or cost, but it failed about halfway through the trip making any long trip a potential cause of leaks.


Secondly is that I have a split in the side of the tip of the overhead camper cab. The split is top to bottom and is about 6 inches tall. It was sealed with as much ProFlex as I could get on it before the trip because I didn't have time to fix it correctly. It also came unsealed because of all the flexing going on during driving.


I was thinking about using EternaBond to fix this on the outside, and possibly even putting a strip on the inside to make it as tight as possible. Short of a professional fix, does anyone know of a better way to repair this?

I will clean and repair these as soon as I recover from the trip, but want the work to be worthwhile.

[Mich_F]

Juzaxadar wrote:
Mich, when you say "molding" do you mean this?


I would have thought that the screws along the outside don't go through the metal frame and into the wall on the other side.

That is what I am referring to. If you go back and look at the picture I posted on 12/1, that should give a better idea of how everything goes together. The molding pieces do screw all the way into the sidewalls frames, and then they are caulked on both edges to seal those seams. The front wall screws into the side wall framing, so with that wall in place, your side walls won't budge.
In looking at your interior picture, it looks an awful lot like mine did, with the wet area along the bottom radius, and 1/2 way up the front wall. If you look at my picture again you will see that the front wall radius is a piece of foam with a lot of scribe cuts in it so it will make the radius bend.

[Juzaxadar]

Mich, when you say "molding" do you mean this?


I would have thought that the screws along the outside don't go through the metal frame and into the wall on the other side.

[Mich_F]

Juzaxadar wrote:
I actually removed everything in the cabover including that crossbar and the inner window frame. Even with everything removed I couldn't make the side wall budge. I haven't put it back together yet. It'd be nice to figure out how to remove this stuff and see.

The sidewall won't budge because your front wall, even if it has rotted wood, is holding everything together. The front wall is screwed into the front edge of each sidewall, tying the cabover together. If you were to take off the moldings on the sidewall,front wall joint, after removing all that suspect caulking, which should be replaced anyway, you could access and remove the front wall, which more than likely has a lot of rotted wood in it.

[Oldme]

If you are getting that much "flex" I would be looking
for water damage that has caused the front frame to rot.

Removing the interior paneling will expose the framework
and still allow the outside to stay together while you
inspect. Of course you would have to replace the paneling
and repaper or paint it. If it is in good condition or after
repairs it would also allow you to add insulation before
re paneling.

[Juzaxadar]

I actually removed everything in the cabover including that crossbar and the inner window frame. Even with everything removed I couldn't make the side wall budge. I haven't put it back together yet. It'd be nice to figure out how to remove this stuff and see.

[Mich_F]

If you had removed those molding pieces on each side, you would have seen that it's easy to remove the front wall to check it. I'd suggest that you remove all the sealant along those moldings and reseal, since it seems like you might not have found the source of your leak/leaks. :B
My front wall, with no window, had wood that was totally soaked.

[Juzaxadar]

So I took this crossbar off. It bridges the middle between the two cabover "floor" boards.


After looking around I decided to not dismantle the cabover any further.

The crossbar is "T" shaped with the T post sticking up between the two floor boards and then screwed into from the inside. It sandwiches those boards and provides some structure. Even though the leading edge in the picture is on the bottom of the cabover (outside), I still feel like it could be a source of leaks. So I think I will take the bar back off and run a bead of dicor or proflex on the inside corners of the "T". That way when it is pressed back together against the fiberglass it will have a good seal.

I just used eternabond to fix the front side. The second side didn't have a crack, but I put it there for the sake of uniformity and because the sealant on that edge shakes loose during prolonged travel.



I had this short (~4") crack on the rear wall. This is a tiny piece so I'll be able to find a sticker to cover it.



Since I have a lot of eternabond left, I am cleaning up the top leading edge between the cabover the the main RV body. I'll put it there.

[Juzaxadar]

That makes a lot of sense.

[Mich_F]

It could be that your cabover section extends out more than mine. Mine has no windows, is not particularly deep, and had an entertainment center, not a bunk up there. There aren't any seams in the forward corners.

[Juzaxadar]

That's interesting. Mine has a seam and one of the side pocket walls screws in at that point. They're wood screw though and not metal.

Mine also has a window on each side and a seam behind the window where the cabover meets the main body.

Thanks for the picture, that's pretty helpful.

[Mich_F]

Perhaps this picture will give a better idea of what you're dealing with ? Your part 1 and 2 are, or were, one piece. It is/was one large piece of foam that was made to fit inside the frame, as well as have a lip that went over the outside of the wing frames. On the outside of that was door skin, which the fiberglass was glued to.

[Juzaxadar]

I will post a pic... but yeah, Mich's looks exactly like mine.

The two floorboards of the cabover attach in the middle with a metal bar that sandwiches between inside and out.

#1 on my crude sketch here is the most rotten part because the tear in the fiberglass there.

#4 has some water damage but seems fairly solid.


I'd really love to take #1 out and make a new piece for it, but I can't figure out how to get it out without breaking stuff.

I think I might peel up some of the carpet at the front of the front cabover floor and see if I can find the seam there. If it's just a flat piece I can make a new one pretty easy. Getting it out and in without damaging everything else is the tricky part.

[Mich_F]

Drew E, my Coachmen, which I sold last month, was built similar to what you described. My 2001 Itasca is more than likely the exact same construction as Juzaxadar's, since they are the same model and only a year apart in age.

[DrewE]

On my Coachmen, the front of the bunk board doesn't really attach per se. The board itself extends to the curved portion, and then a separate, relatively light wood framework of strigners/formers shapes the curve, and then the front wall is again a rather monolithic structure (i.e. a foam sandwich with framework and such). This light framework does not attach to the bunk board—just to the outside walls and the front wall. The bunk board is presumably supported at the sides by the side framework of the cabover structure, but I haven't personally had to examine that part. (If it weren't, I am pretty sure it would end up crashing through the windshield whenever the cabover bunk is used.)

On my unit, the bottom curve framework is readily accessible from the inside by removing the bunk mattress/cushion and then removing an angled upholstered kick panel that goes between the bunk board and the front wall on the inside. This kick board is mounted with a few screws covered by upholstered snaps; about five minutes of work tops to remove it. I'm sure manufacturers and models differ in such details.