Info on KZ ?aluminum laminated? walls

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BernDog

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Sep 6, 2020
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I?m going to be visiting a potential purchase next weekend, and I?m getting stuck in my pre-research. I?m looking at a 2007 KZ Jag TT. The siding is apparently laminated aluminum. It?s flat sheet aluminum, but it looks like it?s built about the same as laminated fiberglass. More specifically, it says ?Built With KZ?s Aluminum Laminated Walls? on a sticker by the door.

I?m assuming that means it?s just like laminated fiberglass, but with aluminum instead, but I haven?t been able to find anything about this process online. Wondering if anyone could either point me in the direction of more info, or if anyone has any firsthand knowledge. Were there problems with this process? Was it too expensive? Anything I should be wary of? Seems like it must have been pretty short lived, at any rate.

Any info would be much appreciated!
 
I think you will find that the framing is 1" x 1" aluminum with Styrofoam insulation between.  The exterior is very thin plywood panels with a paper thin coating of fiberglass.  Look for a very slight irregularity every 4 feet that identifies the panel edges.  The interior is thin paneling with a vinyl decorative surface.  All of this is glued together and run thru a pinch roller.  Expect to find only 3 or 4 full vertical "studs" over the entire length.  The only thing expensive about it is the sticker.
 
So, the “aluminum laminated walls” means aluminum framing with typical fiberglass laminate on the outside? I thought it was some rare beast that might have been somewhat experimental and didn’t pass longevity tests or something. Good to know. Thanks!

Edit: And by too expensive, I meant as a manufacturing process, not sticker price. I know what to expect in general. This is the price point we’re looking for.
 
I was just making a joke about the sticker on the outside advertising the walls, not the price. 
 
There are indeed trailers with a flat aluminum sheet as the sidewall skin and they aren't just an experiment. Holiday Rambler made them for years, even including their high-end Presidential models. And of course, Airstream has always used aluminum sidewalls.

Here's a video of a 2007 Jag. It's just video, but the gloss of the sidewalls suggests that it may indeed be aluminum sheet rather than fiberglass. Hard to be sure, but usually 10+ year old fiberglass isn't very shiny.
https://www.youtube.com/watch?v=sjAbVY4SiOs
Here's another still photo:
https://www.coppercityrv.com/product/used-2006-kz-jag-28-bh-1214032-29
 
Thanks, Gary. I?d actually seen that video you linked as well. I went through a number of those walkthrough videos to see if anyone mentioned it. If it is aluminum, do you know if it would be as susceptible to the same kinds of delamination issues as a fiberglass shell? Obviously there would be problems with any camper with moisture intrusion, but I?m wondering more about the manufacturing or aging process in general.
 
Delamination has nothing to do with the type of outer skin material. Rather, it's related to the method of sidewall construction. Laminated walls are (as the name implies) made in layers, permanently glued (bonded is the technical term) together.  De-lamination simply means the layers have come apart.  That can happen if the glue fails, or it can happen if one of the layers deteriorates.  Moisture is a common cause of either of those, but not the only cause.  A typical laminated fiberglass wall is a thin skin of filon bonded to a substrate of luan plywood. Aluminum sheet could be used instead of the filon, but that isn't common. Most aluminum skinned walls are not bonded - the aluminum is riveted or screwed to the frame. That's how Airstreams and Holiday Ramblers were built.

I see no rivets or screws in the Jag photos, so if that skin is in fact aluminum, it is probably bonded to a substrate.  If there is a substrate (like luan), it can decompose, and if there is an adhesive it can loosen up. So yes, a laminated aluminum sidewall could delaminate.

Most aluminum-walled RVs aren't laminated. The ones that have aluminum skins are either the Airstream/HR type with aluminum sheet or the corrugated type where aluminum strips are fastened to the underlying frame.

All this is interesting tech stuff but the question remains whether K-Z meant "aluminum frame with laminated sidewalls" or "laminated aluminum on a frame".  ???  Today's K-Z trailers with laminated walls use a filon (fiberglass) skin,but what were they doing in 2007?
 
So none of that really changes what I?d be looking for in a walkthrough inspection. Good to know.

I?m still wondering about the aluminum skin, if that?s what it actually is. I?ve read of several manufacturers doing this (aside from the riveted/screwed method, like Airstreams). I?m also just curious as to the pros/cons of this method. It doesn?t seem too common. Would it be a good middle ground between traditional aluminum and fiberglass? Was it better or worse at something? Lighter? Cheaper? I just can?t find any discussion or description online.
 
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