...joined together--vertically or horizontally?

[zer0pi]

I just joined this great forum and have already benefited from those who were willing to share their experiences and expertise.
Even if all goes well, I am still ten years away from retirement and full timing. For now, I go camping on weekends and on vacation, mostly in National Forests and on BLM (see avatar).
However, through research into fiberglass trailers and through this forum, I have recently developed the idea of adding more comfort to my current trips and borrowing a bit from the future, by purchasing a fiberglass trailer now, which would still serve me well when I can full time later. If I purchased a Chinnok or pickup with camper slide now, it would likely be in considerably worse shape in then years’ time and cost much more to keep up in the meantime, than a fiberglass trailer, which could conceivably be in better shape in ten years than now and it wouldn’t matter whether I am still able drive my current vehicle (2006 Jeep Liberty CRD) then.
So, before I actually make my purchase, I thought I might solicit some feedback on a conclusion I have reached.
Like it or not, even (molded) fiberglass trailers have to have seams (where the two halves meet), and it seems most (all?) FG trailers fall into two basic categories, those with vertical seams (i.e. Burro, EggCamper) and those with horizontal ones (i.e. Scamp, Casita). Am I completely off the mark, if I think horizontal seams are preferable, apply less stress on the seams, based on the vibrations while traveling and the pressure from gravity? I realize fiberglass seams are very different from seams in traditionally built RVs, so it may not make any difference whatsoever and my question may be entirely trivial, but somehow it just makes more sense to me join a bottom half to a top half (with slight overlap?) and have less exposure to leaks than if a right and left half are joined. Any thoughts? Thanks.

[Shirley LaMoine]

Chris, your observations of the two types of trailers are correct. I feel that more important than how the trailer sections are connected together is the number of openings through the hull to the outside elements. There are 2 types of trailers - single hull and double hull. Single hulls depend on rivets to attach cabinets, among other things, to the hull. Double hull trailers don't have that issue.

[Byron Kinnaman]

I can't say about other trailers, but Scamp the seam around the middle has 2 layers of fiberglass on the inside of the trailer over that "seam" making it the same as a seamless shell.

There's been a lot of noise about rivets through the hull. These trailer have been built for about 40 years and some of the first ones are still being used. A rivet is easy to replace if it should cause a problem. My trailer is almost 8 years old at this time and so far no rivet problems.

I believe the double hull vs single hull argument is advertising hype.

[Donna D.]

Originally Posted by Shirley LaMoine

There are 2 types of trailers - single hull and double hull. Single hulls depend on rivets to attach cabinets, among other things, to the hull. Double hull trailers don't have that issue.

Escape is a single hull trailer and doesn't use rivets. There are also owner rebuilds on single hull, where the rivets were eliminated through mount blocks. While the Lil Snoozy isn't a really double hull, they don't use rivets either.

I don't think rivets are a biggy. To me it's more about layout. Double hull trailers are pretty much set, single hull is a different story.

We've seen leaks happen at the seam, both horizontal and vertical and others that have never leaked and never will. Whether one is better than the other? If I liked everything about the trailer, seam placement wouldn't even be on the radar. YMMV

[Thomas G.]

Seam leaks are very rare as the seam is fiberglassed over on the inside. The double hull is more of a finishing touch than a structural benefit. As Donna has mentioned, attaching blocks can be fiberglassed to the inside of a single hull in place of rivets, though rivet leaks are not a common complaint here.

[honda03842]

I believe seam leaks are extremely rare. Leaks tyoically occur around openings in the fiberglass, windows, vents, .... Seam location is not a consideration for me with respect to strength or leaks.

Given a choice rivets should go, I like a smoother surface. Saying that they seem to work and over the long term, our trailer is now 22 years old.

[Victor Benz]

Originally Posted by zer0pi

Like it or not, even (molded) fiberglass trailers have to have seams (where the two halves meet), and it seems most (all?) FG trailers fall into two basic categories, those with vertical seams (i.e. Burro, EggCamper) and those with horizontal ones (i.e. Scamp, Casita).

Not all Fiberglass trailers have seams. The Fiber Stream that I own does not. Having said that, the seam question was not even on the radar when I was looking, since I believe seam leaks are uncommon.

Vic

[Bob Miller]

As several have mentioned, I don't think that the assembly engineering should be a concern and would put condition, condition and condition, as well as size and floorplan ahead of that issue.

That said, in as much as most of the vertical seam FGRV's are well up in age, it might be a good idea to inspect carefully for any present or past leaks.

My 40 y.o. Hunter was, I believe, stored outside in the San Francisco Bay area most of it's life and, in rebuilding, I didn't see any evidence of water intrusion except around the refrigerator vents where wind-blown rain may have entered through the louvers.

Now there is, I believe, a third and fourth option: The Hunter Compact Jr seems to be made of 4 pieces, with both kinds of seams, and the Fiber Stream who's claim to fame is no seams.

And no, contrary to what some have yet to suggest, rivets are not a big issue nor do they increase fuel consumption in the TV. (LOL)

Bon Appetite

[floyd]

Originally Posted by Byron Kinnaman

I can't say about other trailers, but Scamp the seam around the middle has 2 layers of fiberglass on the inside of the trailer over that "seam" making it the same as a seamless shell.

There's been a lot of noise about rivets through the hull. These trailer have been built for about 40 years and some of the first ones are still being used. A rivet is easy to replace if it should cause a problem. My trailer is almost 8 years old at this time and so far no rivet problems.

I believe the double hull vs single hull argument is advertising hype.

What Byron said!

[Thomas G.]

Originally Posted by Byron Kinnaman

..........
I believe the double hull vs single hull argument is advertising hype.

When UHaul built their campers with a double hull design, who were they trying to impress? They were for their own use, not for sale.

[Bob Miller]

I am guessing that U-Haul's thinking is that when a customer hit a tree with the trailer, as they apparently often do with trucks, that limiting the damage to the exterior shell would reduce repairs to the interior and hasten turn-around time. In other words, the outer shell serves as a bumper to protect the interior.

At one time U-Haul caught a lot of flack for high flat rate charges for truck scrape repairs and then not fixing them until the same place had been hit several times.

[David Tilston]

As some have mentioned, there are trailers that don't have a seam. Escape bolts the top and bottom mould together then lays the fibreglass. They rivit on a belly band to cover the mould seam, which is just the small ridge, typical of two part moulds on item like a plastic bottle.
Most other trailers are made as two parts, which are joined together. This is required for trailers like the Trillium 1300 and 4500, since the furniture is moulded as a unit and installed before the half's are joined. This is also true of the double shell designs.

Seam leaks are uncommon where there is no freeze thaw cycle. Unfortunately due to the method Trillium used to join the half's, leaks do happen on the belly band. This is explained in the following threads, as well as my method for dealing with it:
http://www.fiberglassrv.com/forums/f...d-58763-4.html
http://www.fiberglassrv.com/forums/f...ead-59580.html

[Jared J]

My scamp had a seam leak, it happens.

[Andy B]

My 1980 Burro had significant cracks in the center seam. The seam was cracked both front and rear where it meets the floor. It was cracked in front at the top and bottom of the window and in the rear at the bottom of the window. When they made the Burro they glued the halves together with thickened resin, but did not use any fiberglass to bridge the seam. The cracks went all the way from inside to outside.
Pictures of the cracks can be seen in post #27 at the following link.
http://www.fiberglassrv.com/forums/f...d-43697-2.html

[mary and bob]

[QUOTE=Thomas G.;418836]Seam leaks are very rare as the seam is fiberglassed over on the inside.

Seam leaks weren't rare on our Uhaul, I had at least two. One aft of the roof vent would drip right through the fiberglass, no hole or crack was visible. Another leak forward of the vent would weep down to the front window. I think ours must have been either a monday morning or friday afternoon assembled trailer.

[mary and bob]

[QUOTE=Bob Miller;418910]I am guessing that U-Haul's thinking is that when a customer hit a tree with the trailer, as they apparently often do with trucks, that limiting the damage to the exterior shell would reduce repairs to the interior and hasten turn-around time. In other words, the outer shell serves as a bumper to protect the interior.

Our Uhaul had either been hit in the rear or backed into something that went through both outer and inner shells. Also lower front damage but in the storage area where it is only a single shell, but I think it also hit the storage tub too. I've seen a lot of truck body damage when I spent 20 years with Ryder. Low bridges really do a job, and one of our lease customers caught the crane on their flatbed lumber truck under a railroad bridge, the front wheels of the truck came up off the road and the top of the cab hit the bridge distorting the whole cab. The truck was totaled and they had it only 3 days.

[zer0pi]

You guys are really generous with your insights. Thanks to all who responded. Today, I took the plunge and agreed to purchase a Casita Patriot Deluxe. Will collect it in a couple of weeks and then thoroughly examine it for leak potentials and hopefully seal off anything which looks vulnerable. Really excited about my new project and the prospect of deluxe camping (compared to my current setup).