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How Do You Build A Dry Caravan?


BFM
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There is an enormous wealth of knowledge on this forum. There seems to be agreement that there is something in caravan design and manufacture that makes it very difficult to make a guaranteed dry van. So here's a challenge, and it a serious question. . Is it possible to build a van that weighs under 1200kg, is tough enough to be shaken around, won't suffer condensation, won't leak and is useful as living quarters? Is there something that the makers are missing? Is there the expertise and lateral thinking required right here on this forum, perhaps?

Enjoy every minute of every day. It doesn't last nearly as long as you'd like, and there's no guarantee of coming this way again.

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IMO a dry caravan is partly possible.

They can and do make them that do not appear to leak.

The problem starts when looking at your question of condensation, getting enough ventilation to prevent it yet also keeping enough warmth in the van especially this time of year is another challenge.

A seemingly problem free 2010 model Adria Altea 542dk that has more than its fair share of use.

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Met a Scottish guy and his wife in the Vendee a number years ago and he built his own caravan.

 

He said it was possible it was a male menopause thing!!!

 

Here's some photos I took. ... was built in fibreglass IIRC. ...

 

G

 

DSCF0022-1.jpgDSCF0020-1.jpgDSCF0021-1.jpg

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I think in the main that caravans are well designed ( layout may be another matter ) and if they were constructed on the shop floor as they were intended to be then most if not all water/damp problems would be eliminated.

 

It only takes one man either through ignorance/idleness or malice to incorrectly apply some sealant or whatever and you have a damp van somewhere down the line.

 

Ian

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Maybe a one piece fiberglass shell with all the structure built in for tnternal / external mountings they manage to make boats that dont leak.

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How about a GRP shell moulded then joined to be one piece bit like an egg shell. This being stiffened by internal ribs of a plastic composite for strength and for the furniture etc to be attached too. the internal shell/ walls being a similar moulding which is then injected with expanding polyurethane foam, between the shell skins.

 

You have created a basic structure which is very light - strong - impervious to water and does not rot. This system has been used in boat building for years and creates a boat that is structurally strong and lighter than the water that it float in. I have personally sailed an Etap yacht years ago, that used this system, with the sea cocks fully open and flooded, it would not sink and the shell stood up to the abuse easily.

 

Problems may be the smell of the GRP. The cost of production and the usual GRP jel coat cracking etc. But it would not rot even of it leaked which would be unlikely. Weight I haven't a clue.

 

Failing that wait for Bailey to develop a composite floor that does not contain wood.

Kia KX 3 auto / Bailey Alicanto Grande Estoril and Swift Challenger 570 (2010 model Not towed - used as a static)
 

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How about a GRP shell moulded then joined to be one piece bit like an egg shell. This being stiffened by internal ribs of a plastic composite for strength and for the furniture etc to be attached too. the internal shell/ walls being a similar moulding which is then injected with expanding polyurethane foam, between the shell skins.

 

You have created a basic structure which is very light - strong - impervious to water and does not rot. This system has been used in boat building for years and creates a boat that is structurally strong and lighter than the water that it float in. I have personally sailed an Etap yacht years ago, that used this system, with the sea cocks fully open and flooded, it would not sink and the shell stood up to the abuse easily.

 

Problems may be the smell of the GRP. The cost of production and the usual GRP jel coat cracking etc. But it would not rot even of it leaked which would be unlikely. Weight I haven't a clue.

 

Failing that wait for Bailey to develop a composite floor that does not contain wood.

 

I was talking to a salesman at a dealers recently who said that Bailey were developing a composite floor but were having problems with condensation.

 

How true this is I do not know.

 

Ian

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I doubt if the manufacturers would try very hard to make one. After all, they make a living out of selling and a new concept van prone to last a conciderably longer time would deplete their market share, also they would never get away with charging twice as much for one that last twice a s long so its never going to change.

Im back to motorhoming with a scooter on the back again.

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Said this in the past. caravan manufacturers should look at the aircraft industry for design and materials as they are sadly lagging behind. MMMF's. ( Man Made Mineral Fibres ) have strength and very light with a monocoque design keeps the water out. .. Then again you could buy my 2004 Ace Jubilee Statesman still dry as a bone since brand spanking. .... ;)

 

GAS . ..... :angry:

"to be auld and wise you must first be young and daft "

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How about a GRP shell moulded then joined to be one piece bit like an egg shell. This being stiffened by internal ribs of a plastic composite for strength and for the furniture etc to be attached too. the internal shell/ walls being a similar moulding which is then injected with expanding polyurethane foam, between the shell skins.

 

You have created a basic structure which is very light - strong - impervious to water and does not rot. This system has been used in boat building for years and creates a boat that is structurally strong and lighter than the water that it float in. I have personally sailed an Etap yacht years ago, that used this system, with the sea cocks fully open and flooded, it would not sink and the shell stood up to the abuse easily.

 

Problems may be the smell of the GRP. The cost of production and the usual GRP jel coat cracking etc. But it would not rot even of it leaked which would be unlikely. Weight I haven't a clue.

 

Failing that wait for Bailey to develop a composite floor that does not contain wood.

 

Hi Alan. The attached image is of a prototype caravan that I saw back in 2006. I was actually quite taken aback by the general shape and contours and later found out that it was one of a few that had been commissioned by an overseas buyer (Holland I believe) and the deal fell through after some controversy about the finer details of development costs.

 

post-37348-0-38728500-1386450688_thumb.jpg

 

 

 

The absence of awning rails surely goes a very long way towards a resolve on water ingress. I also believe that the sides were very very slightly outwardly bowed and that would offer added strength and resistance to buckling and inward bowing.

I believe that flat sides is so often the cause of leaking at the tops of the window apertures and especially when combined with the buckling/bowing of the side panels.

I saw this prototype in a very near stage for rolling,the company moved location and then went into receivership some several years later and then was resurrected. I don't know whether the prototype survived all of the chopping and changing.

 

 

 

The image below is of the basic prototype concept but as it reached the buying public.

The basic concept went into a rather short lived production run under the name of Voyager. Below is the Voyager Vector 650.

The caravan came in with a rather high price-tag albeit a rather compact twin axle and exceptionally high quality cabinetry and interior fixtures and fittings. At the time the price-tag was on par with the Buccaneer range from Elddis,but in my opinion it left the Elddis Buccaneer for dead.

 

 

 

 

photo-x-$14009601$326.jpg
Edited by TheTravellingRooster

Life in general can be a journey of chance with some winners and sadly some losers. Your outfit can never be left to chance. A short-while carrying out essential checks can ensure a long-time of happy & safe caravanning for all concerned.
Ignorance can often be bliss but is certainly not an excuse and when continually disregarded they can be totally disastrous for oneself and the innocent parties.

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Hi Alan. The attached image is of a prototype caravan that I saw back in 2006. I was actually quite taken aback by the general shape and contours and later found out that it was one of a few that had been commissioned by an overseas buyer (Holland I believe) and the deal fell through after some controversy about the finer details of development costs.

 

attachicon.gifPrototype. jpg

 

 

 

The absence of awning rails surely goes a very long way towards a resolve on water ingress. I also believe that the sides were very very slightly outwardly bowed and that would offer added strength and resistance to buckling and inward bowing.

I believe that flat sides is so often the cause of leaking at the tops of the window apertures and especially when combined with the buckling/bowing of the side panels.

I saw this prototype in a very near stage for rolling,the company moved location and then went into receivership some several years later and then was resurrected. I don't know whether the prototype survived all of the chopping and changing.

 

 

 

The image below is of the basic prototype concept but as it reached the buying public.

The basic concept went into a rather short lived production run under the name of Voyager. Below is the Voyager Vector 650.

The caravan came in with a rather high price-tag albeit a rather compact twin axle and exceptionally high quality cabinetry and interior fixtures and fittings. At the time the price-tag was on par with the Buccaneer range from Elddis,but in my opinion it left the Elddis Buccaneer for dead.

 

 

 

 

photo-x-$14009601$326.jpg

 

I remember seeing the pictures at the time. It should answer the problems. I've yet to see any proposals for a twin walled GRP skin with injected polyurethane between the skins with composite framing as well. That's not to say nobody has done it, just I've never sen it except in boats.

 

If the body is made of materials that will not rot then leaks would become a minor not major problem. Logically there is no reason why it can't be done. The same with design. We have this tradition in England of making vans with the lounge at the front. Full of holes for windows etc. A solid wall presents far less areas for water to enter under the pressure of towing. Some of the alternate interior layouts that say Adria and other continental manufacturers do are very logical and work very well.

Kia KX 3 auto / Bailey Alicanto Grande Estoril and Swift Challenger 570 (2010 model Not towed - used as a static)
 

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If they make boats that don't leak why do they install a bilge pump to pump the water out? ;) I think it would be possible to make a caravan that was watertight for at least 20 years but the design and weight may not be to everyone's liking and the cost would probably mean it would only sell in small numbers and so the company would fold after a few years. The first caravan I bought back in 1980 was a Sprite Alpine of 1972 vintage and the roof overhung the sides of the van so for water to get in it would have had to travel up. I know water can travel up but not as easily as it can travel down. I have not seen a similar design since for some reason. I think a combination of ideas could herald the end of the leaky van but as said before would the manufacturer actually WANT this if it sold fewer vans in the long run?

2004 Citroen C5 2. 0ltr diesel auto VTR and 2011 Bailey Orion 430/4

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If they make boats that don't leak why do they install a bilge pump to pump the water out? ;) I think it would be possible to make a caravan that was watertight for at least 20 years but the design and weight may not be to everyone's liking and the cost would probably mean it would only sell in small numbers and so the company would fold after a few years. The first caravan I bought back in 1980 was a Sprite Alpine of 1972 vintage and the roof overhung the sides of the van so for water to get in it would have had to travel up. I know water can travel up but not as easily as it can travel down. I have not seen a similar design since for some reason. I think a combination of ideas could herald the end of the leaky van but as said before would the manufacturer actually WANT this if it sold fewer vans in the long run?

 

This is what I was going to say they make boats that don't leak so put wheels on them

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There appears to be many reasons why some may leak.

You only have to look at the surface area available for sealant on one manufacturers aluminium extrusion to start wondering how it even passed the design stage, when these problems are widely known.

The same build process leaves a reasonable airgap between the panels, right where 2 insulated panels finish there is a cold aluminium extrusion, surely this is going to create a cold spot which will only cause condensation where it cannot be seen day to day.

It keeps getting mentioned about composite floors, this is only going to mask the issues caused by ingress, it will not solve them.

All the issues are easily fixed with some forethought, again it boils down to the fact whilst people keep buying they are unlikely to change things.

 

Dave

A seemingly problem free 2010 model Adria Altea 542dk that has more than its fair share of use.

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So - we seem to be saying that a solid (sorry, used in the normal sense) GRP shell is one thought. There is an issue with this of course, with delamination and so on. What about a large plastic (polycarbonate? Whatever they use for car bumpers) single moulding. The technology for moulding large single objects is there and it is going to be very light and completely waterproof. How would we deal with condensation? Good venting, perhaps?

Edited by BFM

Enjoy every minute of every day. It doesn't last nearly as long as you'd like, and there's no guarantee of coming this way again.

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With the Hymer, any water ingress is not a problem as all the panels have closed cell polyurethane foam, so for instance if a small hole was made, the water wouldn't go anywhere, it's then a matter of a cosmetic fill and spray.

The system is not perfect, but for the price I believe it's as good as it gets. .. :D . .Peter

Peter and Sandy pulling a 2016 Coachman VIP 565 with

2016 Ford Kuga 2. 0. 180 ps. Titanium Nav.

Retired and loving it.

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The answer lies in the build, a bit like cars. If you look at the average age of a car today it is way lower than the tanks of old. If the build was made to last, fewer vans would be sold and we would see the industry crumble. Vans are built to look good and appeal to out cosmetic and vanity side but they are not built strong so we can change our minds and pump more into the builders pockets.

 

Whilst there is a need for vanity, there will always be an ever changing ownership battle. Ask yourself this, how many people keep their cherished vans for longer than 5 yrs, not many so once it has outlived its warranty and usefullness on the vanity side, off we go for another and the latest gismos. The industry does not want to change its builde to a more stable and longer lasting van, they simply put more effort into creating a van that gets the juices going with gismos. Ive never met a woman (those that decide) who would go for impregnable side walls that didnt leak, over a kitchen and bathroom that shone . ...EVER.

Im back to motorhoming with a scooter on the back again.

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Is not the Voyager dished up as the Monopod now?

 

Caravans are made in Aussie market that are dry and made to go off road and not shake apart.

 

Dave

Jeep Commander 3. 0 V6 CRD

Isuzu D- Max Utah Auto

Elddis Crusader Storm 2000 Kgs, Unipart Royal Atlas Mover .

 

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I remember seeing the pictures at the time. It should answer the problems. I've yet to see any proposals for a twin walled GRP skin with injected polyurethane between the skins with composite framing as well. That's not to say nobody has done it, just I've never sen it except in boats.

 

If the body is made of materials that will not rot then leaks would become a minor not major problem. Logically there is no reason why it can't be done. The same with design. We have this tradition in England of making vans with the lounge at the front. Full of holes for windows etc. A solid wall presents far less areas for water to enter under the pressure of towing. Some of the alternate interior layouts that say Adria and other continental manufacturers do are very logical and work very well.

Hi, yes this van was shown at the NEC 2006 Tommy Green and myself had great feed back from the public but i think the price was prohibitive.
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Bilge pumps are fitted to boats in case they take a green wave over the top with a hatch open or in case they are holed.

Alan

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Hi, yes this van was shown at the NEC 2006 Tommy Green and myself had great feed back from the public but i think the price was prohibitive.

 

Hi Roger. Are you referring to the finished Voyager or the naked prototype that I posted?

How much do you know about the Voyager and did/do you know anything about the prototype?

Who was Tommy Green and how did he fit into the Voyager concept,if that is what you are referring to?

Life in general can be a journey of chance with some winners and sadly some losers. Your outfit can never be left to chance. A short-while carrying out essential checks can ensure a long-time of happy & safe caravanning for all concerned.
Ignorance can often be bliss but is certainly not an excuse and when continually disregarded they can be totally disastrous for oneself and the innocent parties.

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Ask the Germans!

David

Various vans 78-2019,  currently  Hobby Excellent 540 FU and Mercedes E220 CDI Estate

www. caravan-europe. co. uk

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Hi Roger. Are you referring to the finished Voyager or the naked prototype that I posted?

How much do you know about the Voyager and did/do you know anything about the prototype?

Who was Tommy Green and how did he fit into the Voyager concept,if that is what you are referring to?

Hi, if you search for tommy green in caravan talk all will be revealedy, but if I tell you who I am I would have to kill you. LOL cheers roger

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