# Motorhome Construction - what is best



## peedee

I ran a poll on body types >here< which produced some very useful comment from members. I am hoping this post will do the same because I am in the market for a new motorhome.

Prompted by the latest post about cracks appearing in bodywork, are manufacturers taking too many short cuts with construction? Some sandwich panels look very flimsy to me and I have heard some are not even bothering to put in frames for doors and windows and are just simply cutting holes in the panels before fitting these. So where is the strength to resist today's pothole strewn roads?

It seems to me that the old construction methods of building on a frame and then cladding it is far superior especially with a one piece GRP roof.

I assume that the old methods resulted in heavier vehicles, probably more expensive to build but was it better?

Comments please or for Dougies benefit "Discuss" 

peedee


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## DTPCHEMICALS

All manufacturers of anything find inovative ways to call the next generation of any thing "improved"

ie the new vw golf has 153 improvements. Gosh the old one must have been a shed

I certainly have my doubts.

dave p


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## peedee

Bump. Does no one have any opinions?

peedee


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## erneboy

A good fibreglass sandwich seems best to me. Obviously that depends on there being sufficient fibreglass, some are very flimsy. My van got an almighty thump recently and amazingly was undamaged, Alan.


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## inkey-2008

The old frame construction is prone to rot if you get a leak that you do not know about. A good sandwich constrution I always think is the way to go. with a one piece GPS roof.
I used to work for a transport refigeration business that made the bodies as well. They used GPS outer covering and ply inner that was then covered with Glassfibre so you had something to attach shelves etc to.
They were very strong and leak proof. 
Find an exflower deliver van, very large body 2" walls on an Alko subframe twin rear wheels low to the ground. perfect motorhome conversion. Or have one made then fit it out. 

Andy


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## bognormike

Interesting point peedee, I know my Pilote has a fairly strong frame, but I suppose the newer ones have economised by using less of the framework, and more bonded panels. The weight question is definitely an issue, 'vans have got bigger but the manufaturuers still want to keep under 3.5 tonnes.

A thought here, if the manuafcturers aren't using so much of a timber frame, how do you go on when climbing on top to clean it or access top boxes etc??


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## twinky

I installed a rear window in my van recently and had a good look/feel of its panel construction.

It is made of a bonded aluminium/polystyrene/hardboard sandwich about 30mm thick. I had cut out a 900 X 450mm piece and was amazed at how light and strong it was.

Every 1 metre or so there are wooden battens which form a frame in the big expanse of the side panels and probably the roof. I would guess this composite would be far less prone to the stress cracks some people are experiencing.

These panels are ideally suited to a slab sided box like shape of our van but would be difficult to form into the more rounded designs which seem to be favoured today.


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## CliveMott

I just put a load of old waffle at the end of the original post!

However, sandwich construction is fine for stiffness and light weight. Polystyrene is not the best structurely but it is by far the cheapest. Those that use foam type stuff in mastic guns for fitting replacement doors and windows will know that this is Polyurethane foam which is much stronger and tenacious. Things are invariably designed to be built, not taken apart!

C.


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## locovan

The fibreglass isnt thick enough, its spread over to big a panel and the Van is flexing.
They should thicken the fibreglass but it is all down to weight and costings.

And potholes are doing a lot of damage nowadays :roll:



Peedee :wink: :wink:


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## sallytrafic

I was chatting at the NEC to a director of a motorhome manufacturer who revealed that another motorhome manufacturer had approached his firm to make the grp shells. They didn't do the work as the quality requested by the other company was far below their standards. 

Incidentally the gazelle helicopter is largely made of honey comb paper with a very very thin sheet of alloy or grp on its outer and inner faces (different parts of the aircraft have different facing materials) . Immensely rigid but you could push a biro through it.


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## locovan

The fibre glass is sprayed on nowadays which if not set right is prone to resin patches with no Matt and these are subject to cracking.
When Hand laminating there wasn't a problem because you can see where your Matt was and tended to be thicker.

Frank that is down to weight ratio isnt it. Always a problem.


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