Lite weight campers & RVs. Consumers/customers need to push manufacturers....

[calicamper]

Lol you ever hear two half deaf people arguing and realize they are arguing two different issues?

First any "composite" built structure you must avoid getting water into the sandwhich structural material. In the sailboat world where we have built "composite" structures since glass construction was discovered we call water in the space between the glass as being wet core it turns your structure into a wet noodle. Solid glass it surfaces as blisters voids in the glass layers where water expands and contracts, also a bad thing.

Moisture condensing in a camper is quite simple. The interior surface gets cool enough to condense the moisture. Its not rocket science. You either reduce the source of moisture, no propane stove use, circulate the air to draw in drier air etc. Why some campers have less issues than others? Simple the surfaces in one camper may stay above the condensation temp better than the surfaces in a different camper. A camper with any type of insulating property be it air space behind wood panel or foam sandwhich composite structure will have a reduced condensation factor over a bare single layer skin type camper.

Its really not very complicated. But I will say one thing boat hulls with inner glass liners require lots of engineering and good builders or you end up with a complete piece of garbage, failing bonding between the two layers, water that does not drain that rots any structure that resides in that gap or just stinks to high heaven. Not to mention weight gain caused my soaked core material.

 

[OCD Overland]

Not talking about a sandwich type construction, but two separate shells with an airspace between. It doesn't matter what the inside shell is, really.

In the Oliver - again I'm only using them as a reference for well made fiberglass - they do use a core in some areas, but it's a fiberglass honeycomb (Nida Core) that isn't subject to rot. I suppose that if you had serious damage to the shell, water could penetrate the Nida Core. Even so, it would be limited to whichever cells within the honeycomb were damaged.

As I understand boat construction - not a boat guy myself - they used to use plywood as a structural core for fiberglass. Perhaps they still do. So if the shell cracks, then water gets into the core and you have rotten wood. Condensation on a massive scale, lol. This couldn't happen to the construction I'm talking about since nothing is there to rot. I do suppose that you could get freeze-thaw damage from water inside the Nida Core, but we're talking serious damage to the shell that you'd surely notice and would likely repair long before problems really occur.

Perhaps it could happen at penetrations? But then those are always an issue no matter the construction. I don't know if water could work it's way horizontally between the Nida Core and the surrounding layers in that situation. Over a long period of time perhaps. It does bring up a good point about leaks, and I've wondered about this myself. That is, if the outside shell develops a leak but the water is draining to the bottom, rather than penetrating the inner shell, then you might not notice the problem. I might ask on the Oliver forums about this to see what they say.

 

[calicamper]

Core materials used in composite builds are typically foam, balsa and cheap builds wood of some type. The term "composite" in terms of resin structures refers to engineered structure using multiple material types glass, carbon / resin and core materials.

A shell over a shell is really no different in terms of condensation than a Aluminum skinned camper with foam board insulation and a inner wall board. The issue with a composite structure bonded to another outer shell which is what your claiming Oliver trailers is doing simply adds cost and requires some smart planning to avoid having the two structures seperate resulting in a unbonded internal structure. That and water finding places to pool between the two structures, they have weep holes to hopefully avoid pooling water issues. This approach isnt really ground breaking, its just added building cost and complexity. This also adds complexity to any type of repair, wiring project etc given your dealing with an internal shell.

 

[762X39]

:lurk:

 

[OCD Overland]

I never referred to the system as groundbreaking, merely well built, as opposed to the floppy, single walled units from Scamp and the like.

I think you misunderstand in that the two shells are not bonded together. They are separately fastened to the frame with some structural connections between the two, but they aren't bonded in the sense that they're laminated together.

As to complexity, that's arguable. Yes, it's an extra shell, but that simplifies much of the remaining construction. The internal shell has all the 'furnishings' - seats, countertops, walls, etc. - moulded into the shell itself, so that eliminates a tremendous amount of fitting out and also saves a great deal of weight. Lighting, appliances, etc., are simply affixed into the shell. As well, it makes the interior every bit as durable as the exterior, easy to keep clean, and free of absorbent materials to hold odors. Wiring is easily done and accessible between the shells. I suggest you take a look at the factory tour thread that I started a few weeks back. It really is a well thought out system, and as I pointed out in my first post, no heavier than most frame and veneer structures, despite the double hulls and their thickness. And contrary to what you say: as I said initially, you can buy a finished camper for less than is being quoted here for a framed unit.

--

You entered this part of the discussion a bit late, but the original argument was that fiberglass shells are heavier and more expensive than steel framed, and that they had inherent condensation problems. My point is that the heaviest, reinforced, double hulled, super insulated, non-condensation troubled, most expensive entire fiberglass trailer I know of, including all the bells and whistles and including the frame and suspension, is still cheaper and lighter than what some here are saying they can stick build a steel framed drop in camper for. I mean, it's a thread about light weight campers after all, and introducing a bit of context seemed appropriate. But it seems that some people are rather religious in their choice of materials.

btw, finished fiberglass is commonly referred to as 'composite' as it's a composite of fiberglass and resin. It doesn't have to be layered or sandwiched with some other material.

 

[boxcar1]

OCD Overland


Please stop invoking science until you understand it.

You're confusing condensation with air moisture content. They are two separate things. Water vapor will not condense unless it reaches its dew point. If the inner surface of the fiberglass is below the dew point temperature, condensation will occur; if it is not, then no condensation. The air outside the shell or between two shells also has moisture content, and that water vapor will obviously also condense if it reaches it's dew point. This is independent of the moisture content inside the camper. No one is talking about moisture migrating through fiberglass.

Mold and mildew can only grow on organic matter. They do not "draw nutrients from the atmosphere". That's lichen. If you have either growing on glass, it is actually feeding on some other organic matter embedded in or attached to the glass.

If you think that mahogany veneered plywood has the same properties as solid mahogany, then you are mistaken. If you did not seal the back and edges prior to installation, then no surface treatment will have much effect on it's ability to absorb moisture. When it's raining, the moisture content of the air outside will far exceed anything you'll produce inside, apart from maybe taking a shower, and the plywood will absorb that moisture. And if you do seal the surface, then guess what - the wood isn't going to absorb the condensation and it will collect on the surface just as if it were fiberglass. It's not magic.

There's nothing wrong with the way you are building - it's a very practical method particularly for the do it yourselfer. And I doubt you'll have problems if you do it right. But don't go around bashing other methods just because you chose something else, especially when it's clear that you don't really know what you're talking about. You're building a standard, heavy-assed steel and wood camper and pretending it's magic. Maintain at least an ounce of humility, and just remember that a fiberglass shell will still be perfectly serviceable 50 years from now; your camper, regardless how well built, will likely be in a landfill long before that.

Re read my post . I am not nor have I ever bashed fiberglass construction . in fact I sed it may hold all of the answers to rv problems when used in mass production , IF DONE RIGHT.
As for mold acquiring nutrients from it's surrounding atmosphere. Have you ever herd of pollen , or any other organic matter floating around in the air. Most hay fever sufferers have.
I have been fighting the good fight for 40 years ( all marine related ) mold and mildew will grow in the dead air space between fiberglass bulkheads .
I seriously doubt that an rv is any different.

Do me a favor , breath into a plastic bag . What do you see? Condensation , the point of this ridicules argument. No dew point required......

My camper comes in at just over 800 lbs fully fitted out as she sits now. All that's left to add is the ridged insulation (60 lbs ), the .035 aluminum skin (35 lbs) as well as the copper fuel lines ( guessing 5 lbs max ), blue flame heater (20 lbs) and 6' of pecs tubing with proper required fittings ( 10 lbs ) and the super vent ( maybe 15 lbs ) + fasteners and sealant. Target weight is 1000 lbs , I think I will hit that mark.
A full 500 lbs lighter than the lightest production hard side camper on the market , of the same size and accompaniment. Including the glass molded alternatives.

I guess that puts an end to your rather rude and uninformed remark about steel /wood/aluminum making for a heavy assed camper.
It needn't be , that's kind of the point.
Will it end up in a land fill ? I kind of doubt it but any thing is possible.

Cost is just under $3000. Again, pretty damn cost effective build.

And all of the teak / mahogany / fir ( as I believe I stated earlier ) is or will be encapsulated in polyurethane...
And yes ' without a doubt will bead water. All corrected with proper ventilation. Again discussed earlier......

Just to quell your concerns : I'm a semi retired mechanical engineer. I have been involved with the construction and design of many more complex structures than an rv for most of my life . Many of them are of glass molded design. Some fly , some float and a few run down the road with big blocks under the hood.

I never have and never will state that my design is better or worse than any other . I believe that my solution to the many problems we all suffer through as rv owners can be addressed by building in this manner though . JMHO

By the way. the Scamp unit was a double wall trailer with molded in cabinets, much as you describe above. I believe they all were.
And I might add your 50 year old glass molded camper will undoubtedly be a blistered delaminating mess by then. Unless you can solve the cracking of gel coat and UV degradation problems that all fiberglass structures suffer over time.

I'm finding it hard not to be rude right now , and I won't drop to that level.......
Look let's just agree to disagree and save each other a ton of grief .

I have enjoyed this conversation greatly and will continue to fallow this thread.

Happy trails all.....

 

[calicamper]

Composit test panels typically have very similar weight ratio to Aluminum. Engineered composit structures are rare to see in RVs because of the labor cost to lay them up, vs chopper gun resin mixed with chopped glass mat sprayed into a mold. Typical rv fiberglass products are simply chopper gun products. Which are heavy and in the composit structure world very weak and have very little engineered structural strength.

These trailers are simply using very basic yacht building composit steps. I wouldnt really consider it better than a well built aluminum camper. Its simply just a different material and build process.

 

[Freebird]

Breath into a plastic bag.....
Body temp (and the moist air you exhale) is 98.6 or very near about.
I doubt ambient air in the room your holding the bag in is anywhere near that warm.....
So moisture condenses on the inside the bag....which is the temp of the room, which is below the dew point of the heavily moisture laden air you just exhaled.
Science IS consistent......
If your a mechanical engineer, you have forgotten your phase changing physics chapter you had to take....

 

[boxcar1]

A simplified example for the mind to ponder .I apologize for trying to make things a bit simpler for someone who just doesn't seem get the idea.
The dew point isn't and never was the issue here. The fact that the rv does or does not have a condensation issue is... IE : cold night warm camper = condensation.....
Look the discussion is and was about building a lighter better built rv.
Got any constructive ideas?
By the way.... try the bag trick on a 100 deg. day You might be shocked.

 

[Freebird]

Boxcar,
I like your build. There are LOTS of ways to accomplish the same tasks. I'm not knocking your build at all.
Just nit picking your physics.
I did put some ideas to this topic (see p. 2). Nobody seemed to care, so there you go...

 

[boxcar1]

I got it. Sorry if I seemed a bit on edge. I had just left the dentist office......
I'm presently going through the prep for lower dentures. Had 2 ( More ) teeth pulled yesterday. I hate getting old........
Now that I think about it , maybe that is why I have such an aversion to clinical RV interiors....

I went back and read your post PG-2 .
I like your ideas.
There are any number of ways to skin this cat.
All but a few are worth consideration.
I realize mine is a bit of a throw back. Not exciting or cutting edge.
More of an experiment to see if it was possible.
For me it was and is all about the chassis.
This same chassis could be skinned with more modern composites for an even lighter finished unit.
No wood required for this build. ( Just my personal preference. )
Say if one was to use thin glass panels or even plastics for the interior walls and cabinet faces. 1/5th of the dry weight could be shaved.
This would net a 13ft hard side with all of the normal conveniences ( save a wet bath ) at 800 lbs. Add a small wet bath ( in place of the large hanging locker ) you'd be back to 1000lbs.
All in a very ridged, light and durable unit....
If it were marketed toward the DIY market as a bare chassis - pre coated with say, PAR 15, ready for skinning. It just might be an interesting cost effective way to go.
Who knows ? It's just something I am toying with at this point.
After all , I haven't finished the prototype yet.

 

[OCD Overland]

Composit test panels typically have very similar weight ratio to Aluminum. Engineered composit structures are rare to see in RVs because of the labor cost to lay them up, vs chopper gun resin mixed with chopped glass mat sprayed into a mold. Typical rv fiberglass products are simply chopper gun products. Which are heavy and in the composit structure world very weak and have very little engineered structural strength.

These trailers are simply using very basic yacht building composit steps. I wouldnt really consider it better than a well built aluminum camper. Its simply just a different material and build process.

I don't disagree. Not every fiberglass product out there is the flimsy stuff, but I could have just as easily used an aluminum box as my example rather than fiberglass - perhaps a VMI Canyon fits the bill even better in terms of weight and cost (and ExPo cred). $25k and under 2000lbs. Smaller and fewer features than the Oliver, but that actually makes it a better comparison to the builds we're talking about here.

I guess my point is that this thread starts with an incorrect assumption - there are lightweight campers and RV's on the market, and they aren't all that hard to find - and ended up advocating builds that are actually heavier and more expensive than what you could just go buy.

And again, if you want to roll your own trailer, that's very cool, and you can even sell them to people who want the customization a smaller builder can provide. But if you want to call it light and inexpensive, or better in some other respect, then we have to ask, well, 'compared to what?'

 

[calicamper]

I don't disagree. Not every fiberglass product out there is the flimsy stuff, but I could have just as easily used an aluminum box as my example rather than fiberglass - perhaps a VMI Canyon fits the bill even better in terms of weight and cost (and ExPo cred). $25k and under 2000lbs. Smaller and fewer features than the Oliver, but that actually makes it a better comparison to the builds we're talking about here.

I guess my point is that this thread starts with an incorrect assumption - there are lightweight campers and RV's on the market, and they aren't all that hard to find - and ended up advocating builds that are actually heavier and more expensive than what you could just go buy.

And again, if you want to roll your own trailer, that's very cool, and you can even sell them to people who want the customization a smaller builder can provide. But if you want to call it light and inexpensive, or better in some other respect, then we have to ask, well, 'compared to what?'

Agreed. The thing that gets people is that even small rigs take labor and time to build so they still are going to cost a pretty penny. Just the nature of the beast. The Sailboat business is the same way. For the past 20yrs builders have built bigger and bigger boats. The typical family 24-28foot sailboat of the 60s-mid 80s is basically dead because a 30-32footer costs just as much to build yet they can sell them for much higher profits. $80,000 28footer? Or a $115,000 32 footer? Both took the same material and labor costs to create. You can see why the trend to up size happens. The RV biz is very similar.

 

[boxcar1]

The VMI Canyon is a neat unit . Well built by any standard. It is however a pop top. And basically a large tear drop style tent trailer. 1900 lbs dry ( Light for a hard side trailer ) and $25,000 .... .
Not really a fair comparison.
The Compass is closer ( at least in fit out ) as it actually has an indoor galley. Still a pop top with canvas sleeping quarters.
As of right now they haven't listed a dry weight ( at least from what I have seen ) . But considering that the Alpine is listed at 17', 3000 lbs dry and $35,950.
I'm guessing that the Compass , 16' will come in just over 4000 lbs. and a bunch more $$$$$$.
An interesting comparison though....
I have been on the trail with others who have DMI's. They are very nice, capable , well fitted out RV's .
For me though , a soft side just won't work. I camp 4 seasons.

I guess my point is that this thread starts with an incorrect assumption - there are lightweight campers and RV's on the market, and they aren't all that hard to find - and ended up advocating builds that are actually heavier and more expensive than what you could just go buy.

And again, if you want to roll your own trailer, that's very cool, and you can even sell them to people who want the customization a smaller builder can provide. But if you want to call it light and inexpensive, or better in some other respect, then we have to ask, well, 'compared to what?'

Just to clarify : I am talking about Hard side slide in campers , not a trailer . I do remember how we got off on the trailer discussion.

I think I have more than shown that my design is both lighter and less expensive than anything comparable and available on the market today .
Is it better?
In some ways I'd have to say yes - JMHO. But truly it's just a different take on an old simple building technique.

 

[Freebird]

I'm the OP, and I haven't seen anything that is available today in a hard side TC that is as light as it could be, nor priced as low as it could/should be with mass production economies of scale.
I am impressed with the Oliver TT. I wish they would do a TC.....