Tuesday, January 18, 2011

End Caps

Most LD owners have seen at least some separation of the end caps, the vertical corner pieces. This obviously can be a major problem in that it allows water iinfiltration that can cause significant damage. Over the years, the Mothership has made some changes in how the corner pieces are installed. Former LD owner Don McGlothen has thoroughly researched this problem and recently posted an updated report:
The following reflects my opinion and experience and is not posted to be anything but just that.
I've seen many ABS End Cap Molding adhesion failures at gatherings of Lazy Dazes, mostly on coaches over two years old. I've seen pre-2004 Mothership end cap repairs that had not failed and many that had. I've been told of a recent Mothership repair of the rear End Cap configurations that has the `joggled' overlap joint between the rear upper and rear lower End Cap sections; that repair also did not last. The overlap joint had been filled with sealant, which I've found leads to a quick failure of upper End Cap adhesion. The reason appears to be that ss the upper and lower End Cap sections expand thermally, the upper cap section `rides up' over the overlap joint and over the sealant in that joint. This essentially lifts the upper End Cap away from the aluminum body side panels and the sealant that holds the end cap tight against the siding there fails.

Those of you with End Cap problems know that the ABS End Caps have come loose in other locations, particularly the lower parts of the both front and rear vertical End Caps. If let go long enough without repair, ABS End Caps will break. They are not strong enough to handle constant flutter in the breeze at 60 mph, or a snag on your St. Bernard's collar. The longer you wait to repair them, the more expensive your repair may be. The end cap sealant fails because of differential thermal expansion of the end cap material and the body siding, and, body flexing.
Not all Lazy Daze End Caps are merely cosmetic, as in some years production, they may protect unsealed wood structure. For some Lazy Daze built before 1999, sealant may not have been applied to completely cover all the wood structure under the End Caps. If you have partially disbonded End Caps trying to protect unsealed wood, you may discover a wet wood problem fairly late in its development.
(Of course, if you never go where it rains, never wash your coach and your large dog is well trained, no problem.) I understand that later Lazy Daze (around 1999 to 2000 and on) have all their wood structure under the End Caps covered with sealant. That should preclude developing a wet wood problem because of end cap disbonding. If you are in doubt about your earlier production Lazy Daze, ask the Mothership.

On our 2001 26.5' Lazy Daze MB, which delivered to its new owners recently, the rear end cap sealant was still in good condition after over two years of service with `Big Stretch" sealant applied where the factory installed adhesives had failed - EXCEPT – In my second and successful repair, I removed all the sealant I could from the overlap joint of the rear end caps. My experience is that correctly applied Big Stretch sealant to attach failed areas of VHB tape attachment will provide at least several years of service without failure. On the other hand, my experience with Parlastic and other PR255 recommended sealants failed after a short time. They just don't appear to stretch enough before they stop holding hands.

There is really good news for the future. The Mothership this year has replaced activated VHB tape bonding of End Caps in their production with a new adhesive. This new adhesive shows real promise for a very long life without disbonding but it takes special equipment to install it and it is not something you can do.

I believe the Mothership could use this new production adhesive to repair in service coaches that have end cap disbonding problems. By carefully applying heat and skillfully wielding a putty knife, any partially disbonded VHB tape adhesive and the rest of its End Cap should be removable. After cleaning off the old adhesive, ABS end caps in good enough condition - or new ones if necessary - could be re-installed on your Lazy Daze using that new production adhesive. Since 2006, the Mothership has done these repairs for a price - ask them. New end caps are often part of this repair. It looks to me that this would result in an End Cap installation equivalent to current new production.


I achieved a long lasting repair of our 2001 partially disbonded ABS End Caps using edge sealing with locally available materials. It really was quite easy to do and I still don't understand why others with the condition don't just fix theirs themselves. End Cap adhesion just stopped being a problem for me and it can for you as well.

Not fixing or having someone fix partially disbonded End Cap(s) will result in further disbonding and perhaps more serious trouble.

I used DAP 3.0 crystal clear sealant to seal the seams and the end caps.
It works well in applications where a white sealant would cosmetically be inapropriate. My prefered sealant is 3M's 5200 marine polyurethane but it is not available in a clear color. Since the seams and end caps are painted in both white and the color of the motorhome, a clear sealant is required to look correct.

To get good penetration in the seams, I applied masking tape to both side of the seams, leaving a 1/4" gap to expose the seam. A bead of the the Dap 3.0 was applied to each seam and then forced into the seam using a gloved finger. The masking tape contains the excess sealant, leaving a clean surface when the tape is removed.

The end caps required a thicker bead that was also forced deep into the gap. Many section of the rear end caps needed two applications to to totally fill the wide gaps.

Proper preparation is needed to insure that the sealant does its job.
The entire rig was wash and dried. Compressed air was used to blow out the seams and then left to completely dry. The end cap gaps were cleaned and scraped to removed any loose paint and old sealant and to provide a place for the sealant to be placed.
You could re-glue the cap and use screws to pull the cap back into place until the adhesive cures and then remove the screws. That might be a better solution since the caps often crack around the screws.
There is a lot of stress applied to the caps, both from the twisting and flexing that the body goes through while on the road, not to mention the thermal expansion and contraction forces. LD builds a strong body that stays that way unless the wood frame gets and stays wet, allowing rot to weaken the structure. Our responsibility is to make sure water does not get in.

Visit Larry Wade's Flickr site to view pictures of repair underway.

You can also find photos of a similar repair here on WxToad's site.

Contributors: Don McGlothle, Larry Wade, WxToad

Revised: 12 Oct 13

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