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De bonding

Which coaches were most likely to experience de bonding, and what were the signs this was occurring?

Thanks
1994 U280 Unihome Grand Villa aka "Lazy Dayzz"                                              Cummins 300hp
    Allison 6 speed

Previous coaches:
1984 Revcon Duke 29 aka: "The General"
1984 VW Westfalia
1976 VW Westfalia

Re: De bonding

Reply #1 –
Quote from: Tomibach –
Which coaches were most likely to experience de bonding, and what were the signs this was occurring?

Thanks
are we talking the exterior fiberglass? If so approx 99-2008 (approx)

guess it depends on how much supply was bought and how much was sold and used... but Those years should be halfway close.. The micro cracks will get worse with heat.. and dark colors.. and I guess it is theoretically possible for a coach to be kept in doors all its life and only used in the spring and cooler months and then for it to be moved west and start showing signs afterwards but most have already go the problem.

Re: De bonding

Reply #2 –
If speaking about "delamination" of fiberglass in exterior walls and roof

- black paint on roof at top of stairs - cracking - all years - early slide rooms - 1999 U-320 E, 2000, and 2001 I believe due to incorrect adhesive on the foam used as insulation - in and around dryer vent - all years (or for that matter check any opening that goes all the awy through the wall to the exterior) - Window opeings in some Nimbus models due to lack of sealant - I want to say 2005 and 2006 but don't hold me to that

The Nimbus issue can be fixed, $$$ will depend on how far the issue traveled before it was address. Non of them that big a deal unless ignored for a long time. Nimbus can hurt the wallet the most.

Others out there may correct me, but these are my recollections.
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)

Re: De bonding

Reply #3 –
Reading Tims response.. He could be asking about Delam also? It can happen with any year with a slide if not sealed and kept sealed around the bladder area (mostly) as Tims response with the Nimbus but depending on the question and what year of coach? I think the Delam if taken care of early isnt such a big deal but looking at Brad and his wrestling match with his inverters is by far more of an issue to be concerned about.

Re: De bonding

Reply #4 –

These are all different things.  A bond line failure is generally between the outer skin and the steel or aluminum framework or insulation where glue is applied.  A delamination failure is where the layers In the fiberglass lamination structure (resin, chopped strand or fiberglass mat, woven fiberglass cloth and gelcoat) separate.  Out gassing from the gelcoat seems to be the cause of paint crazing especially in dark colors. 

If you have slides check carefully around the edges of the slide opening in the coach body.  This is between the outer surface of your coach and the bladder.  These need to be sealed.

If you have window openings in the end of the slide this edge of the outside skin of the slide needs to be sealed carefully

Use a high quality sealant like 3M 4200 UV fast cure.  It comes in black.
Amazon.com : 3M Marine Adhesive/Sealant Fast Cure 4200, 06564, Black, 1/10...
Do yourself a favor and do not use silicone or a runny self leveling sealant.  Use painter's tape around the outside edge to do a neater job.

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Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: De bonding

Reply #5 –
If you are wondering about Grand Villas, delamination is common on the cab sidewalls. Here are a couple of photos from my 95. The arrow points to the area of delamination and the second one shows that area from under the rig after it was repaired. You can see the glue that was squeezed out.
jor
93 225
95 300
97 270
99 320

Re: De bonding

Reply #6 –
Quote from: Roger & Susan in Home2 –
These are all different things.  A bond line failure is generally between the outer skin and the steel or aluminum framework or insulation where glue is applied.  A delamination failure is where the layers In the fiberglass lamination structure (resin, chopped strand or fiberglass mat, woven fiberglass cloth and gelcoat) separate.  Out gassing from the gelcoat seems to be the cause of paint crazing especially in dark colors. 

If you have slides check carefully around the edges of the slide opening in the coach body.  This is between the outer surface of your coach and the bladder.  These need to be sealed.

If you have window openings in the end of the slide this edge of the outside skin of the slide needs to be sealed carefully

Use a high quality sealant like 3M 4200 UV fast cure.  It comes in black.
Amazon.com : 3M Marine Adhesive/Sealant Fast Cure 4200, 06564, Black, 1/10...
Do yourself a favor and do not use silicone or a runny self leveling sealant.  Use painter's tape around the outside edge to do a neater job.


in fact I meant bond line failure..., guess delam was an inaccurate term
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1994 U280 Unihome Grand Villa aka "Lazy Dayzz"                                              Cummins 300hp
    Allison 6 speed

Previous coaches:
1984 Revcon Duke 29 aka: "The General"
1984 VW Westfalia
1976 VW Westfalia

Re: De bonding

Reply #7 –
Quote from: Tomibach –

in fact I meant bond line failure


Are  you referring to cap to coach junction? If so, newer "seamless" or old style with molding?
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: De bonding

Reply #8 –
Hey Tom, the terms are often used interchangeably and most get the idea but the differences are important when you are designing primary aircraft structures and wings using carbon fiber and epoxies. The adhesives used in bonding parts together add weight and every pound of added weight costs thousands of dollars in operating costs over the life of an aircraft. Making parts that fit better to use less adhesive had a big price premium.  Even better making parts that did not need adhesives at all was really a big deal.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN