New Caravan - Construction Methods

Most serious off road motorhomes are built from fibreglass sandwich panel.
When I built our OKA motorhome I used fibre glass sandwich panel on a lightweight steel frame. Having that frame was a mistake.

Cheers,
Peter
OKA196 Motorhome

Use of a sandwich panel would make running wires, pipes etc inside of walls a little tricky. But I guess they are ways to run wires - maybe requires a lot of cupboards so that wires can be along walls in the back of the cupboards????

Alan

How do they repair the Sandwich Panels if they are damaged in an accident ect.

Cheers

The debate on framing, metal versus timber, has been going for years and I guess it will continue now we have the sandwich. When choosing an "off road" van the important thing is to go to the recognized manufacturers. As already mentioned they also use different framing materials. More recently Trackmaster have started using the sandwich panels. Personally we have and Evernew which has a timber frame. One thing I always remember in the aircraft industry, all metal frames, wings etc have a fatigue life, whereas the timber frames don't.

Just my six penneths worth.

Cheers

Racey

I recently had some external panel damage to my Bushtracker repaired at their factory.

There's no doubt in my mind that the damage would have been just as bad if it was fibreglass but it would have been many, many times more expensive.

The entire side panel would have to have been replaced, along with removal, and re-fitting of everything attached to it on the inside.

As it was, just the lengths of alloy panel that were affected were replaced.

The hang up here is conservatism and ''knowing what you know''.

How do you think you would get on if you tried to convince the luxury boat industry to go back to wooden frames with plywood attached? They would laugh at you and so would their customers.

It is undoubtably true that FRP sandwich is more expensive than conventional frame and cladding, especially the material cost, but construction labour would be much cheaper. Most manufacturers (and customers) are driven by cost.

Conventional consruction becomes a ''Catch 22''. They need to be heavy to be strong. That weight means they need to be even stronger (and heavier). That is a really bad downwards spiral if serious off road is remotely on the agenda.

Are fibreglass boats difficult to repair? Not at all, unless you are a cabinet maker.

Fact is thin skin aluminium is not repairable at all. Replacement is the only option short of bog. With fibreglass a repair can be quite localised or very extensive before considering replacement of the panel and the repair will be as strong as the original.

Almost all the wiring inside OKA 196 runs inside cupboards. Having it accessable in this way if necessary is a great bonus. Just needs a different approach.

Cheers,
Peter
OKA196 Motorhome.

Thanks everyone for your replies. There have been a few points made that I had not thought about. A few expressed the view that sandwich panel could be expensive to repair – but even if this is the case this would be covered by insurance for any major damage.
Thanks Member bungarra for your link to Explorex. They seem a very robust built van (albeit a little “industrial looking” aesthetically). However Explorex are made in WA and I want to buy locally in SEQ so I can see my van being built.
We live within 30 min drive to Bushtracker, Kedron, Sunland, Phoenix, and Spinifex factories.
My current thinking (but my research will continue) is that there appears no compelling reasons not to adopt the new construction technology of sandwich panel and benefit from significant weight savings and better insulation. On this basis currently at the top of my list would be a Blue Heeler (Sunland). If I resort to a framed van my current thinking is a Spinifex.
(I have no association with any of these companies – just doing extensive research before I decide).
Thanks for everyone’s contribution – this forum is a powerful research tool.
Cheers

I have just been to a caravan repair shop in QLD and was shown a near new van that as in for repair. It was a timber frame van that had started to leek, the insulation was a joke [very thin and didn't cover the cavity from side to side or top to bottom]. Large holes had been drilled through the sides of the frame for wiring so there was very little timber left.
So yes do your homework there is a lot of rubbish out there.

Cheers
Pat NZ