Roof-Wall Joint

[JimDyer]

This summer, I had to tighten up the roof-wall joint on the passenger side, as water was running down the inside of the wall and ending up in the compartment doors....among other places.  So, I worked my way along the joint from the nose to the rear, removing loose screws and replacing them with SS ones, along with a dose of caulk.  In doing this I discovered that the plastic strip which hides the screw heads is at the end of it's useful working life.

To help identify this there is a metal strip which runs horizontally  between the front and back corners, above the awnings, at the joint between the wall and the roof. It looks similar to the belt-line strip at the top of the basement compartments, but smaller.

Can somebody identify what you call the plastic strip and where to get a replacement?

Thanks

Jim
  

[Tom and Pam Brown]

Jim,  

I cut a piece of mine off, and went to a local camper parts store, and they knew what it was, without any problem.

Replacing it will be tougher than finding a source.

If you have any issues, let me know, and I will research the name of the seal.

[JimDyer]

Thanks, tom and Pam.  I'll hit a few on my way south.

jim

[Tom and Pam Brown]

Jim,

I used a painters scraper to put the seal in and it needs to warm outside, or use a hair dryer.

It is not pliable enough cold, to get into the slot.

Good luck and safe travels...blow your horn if you come through Georgia!

[Jeremy Parrett]

Most power boats have a similar "rub rail" along the edge of the "gunnel"....that is where the deck and hull are
  pop riveted together !!  The aluminum moulding accepts the rivets which are hidden by a rubber filler piece.
 Our coaches have a similar "roof" to "side wall"  joint.  On power boats this "joint" "works" and is a very common failure point leading to leaks and stressed fibreglass.
Two  solutions come to mind.
1) Clean under the aluminum strip thoroughly a section at a time; add caulking to the underside of the aluminum strip, if possible, provide a backing piece (wood or aluminum) inside that will accept the screws, liberally coated with a marine caulking,  wherever you can access the inside of this joint.  Do NOT over tighten these screws or you will squeeze out the sealant and stress the fibre glass  .  Whether you use a backing piece or not do NOT over tighten the screws. Once you start to see sealant oozing out, it is time to stop. If you use Sikaflex 5200, you will create a very strong bond. Cleanup with a spatula and acetone before it cures. Once cured, you can replace the rubber filler strip .......I would use a good sealant to hold the ends in place. You could slightly "crimp" the moulding, to achieve the same effect.
2) bond the roof and wall together by laminating from inside, with fibre glass matt and cloth. Not possible unless you want to remove all the cabinets etc. but done at the factory would have provided us with a structurally sound roof to wall joint that would never leak.
Possibly someone can add to this so we can achieve a uniform semi permanent solution.

[JimDyer]

Thanks, Jeremy and Tom

[Edward Buker]

There are some similarties between a boat hull to deck seam and our RV roof to sidewall but there are differences and you will not be able to get to the backside of the screw locations. There is metal frame within the coach on the backside. This information pertains to a 2002 Marquis and probably the Marquis from 98 to 2002. Other models may have a similar joint and moulding so it may apply there also.

 I had a roof to sidewall separation on the rear passenger side quarter of the coach. In this case the moulding is painted and the top side is sealed to the roof with clear Acrilar. You do not want to break that seal if it is good and you do not want to significantly bend this moulding because the paint will delaminate. The root cause for the fail is the minimal use of cheap fasteners that rusted and failed. I would be reluctant to use 5200 as a sealant here given that it is messy and it requires that the factory moulding joint to roof be broken.

If you have a similar fail to what is in the photo you will need to mechanically refasten the jont. I personally do not like stainless fasteners for this job given they tend to shear and break when cutting threads in metal. I found that a #10 small hex washer head, 1 1/2 inch white ceramic coated steel screws to be a good choice. The bottom side of the formed washer head is made to grip the surface so they do not loosen. They are coated to survive a salt air exterior metal fabrication environment. They just do not rust and are used to build metal panel roof car ports and screen rooms in Florida. The compact head fits behind the rubber strip well and they are easy to drive with a 1/4 hex driver bit.

 I found that drilling the trim strip and fiberglass wall or roof panel with an 11/64th bit until you hit the interior metal frame and then drilling the metal frame with a 5/32 bit to work well. You want the threads to slip in the outer trim and panels and cut threads in the coach interior frame to pull the wall and trim in tight. I spaced the screws about every 4 inches for the length of the trim strip. Caulk each hole with silicone before you drive the screw to seal it.

You are not trying to secure the trim strip to the fiberglass panels, you are fastening the roof and wall panel to the coach frame using the trim strip as a clamp. If the critical top trim joint to the roof is not sealed well you will want to clean it with an automotive paint prep solvent and seal this joint with clear Acrilar. This joint has been trouble free and water tight since it was repaired. Hope this helps.

Later Ed