Fiberglass vs Metal

[sleepygeek]

Fiberglass vs Metal : Which is the better material for the shell of a motor home ? I bought a 1986/87, E-350 Ford, 460 CI V8, Mobile Traveler, I think 24 ft, with a fiberglass body. Would like some experienced opinions which is better in the long run.
My plans are to make this RV my home before I have to go to a old folks home. I have been re-modeling to fit my style of long term living and not just a few camping trips. Will travel when I can afford gas for a trip. Before I invest more into this RV, in your humble opinion, did I go wrong with fiberglass body ?

[sleepygeek]

I aim to keep it off the interstate hwy and just use surface roads, then I might get better mileage. Had by-pass 10 years ago, no heart attack, either way a big scar. I think the tail cap which is the bathroom is smooth molded fiberglass. On my website I have a walk around video of it, link in my signature area.

I added a link to some pix of my progress in my signature area, Here is a link to them here : Some Pix of progress

[Chris_Bryant]

Honestly, at that age, current condition is the key- if there is no delamination now, just keep it sealed up and you'll be fine. The Mobile Travler of that vintage is a fine rig, the 460/C6 combo is good for 200k miles, only downside is above 60 the back two barrels open up, and you get about 5 mpg. I got tired of rebuilding the motor craft/Holley carb, and installed an Edelbrock performer, simple bolt on switch.

Fwiw, I had a customer who was in an Airstream that got struck by lightning, gave him a heart attack (no kidding), blew a hole in the side of the trailer.

[toedtoes]

Also, remember that not all metal is the same. An airstream typed metal panels individually bolted to the frame are a lot sturdier than those aluminum siding types that are dependent upon the corner seams to hold them together.

[toedtoes]

sleepygeek wrote:

Most fiberglass TT and motorhomes are made out of "composite" walls. Some kind of a "backer" and then a piece of fiberglass with resin. This design is usually placed in an oven that melts the resin so that it adheres the backer. Pressure may or may not be used. If the backer get wet, the fiberglass can delaminate.

It may be this type as in the above quote. Smooth flat sheets on the sides, I'll check to see if it has backing glued to. Over cab part looks molded

The photo of an '87 Mobile Traveler I found online, definitely looked molded on the cap. It could be a combined body - molded cap and composite walls.

If you don't have a problem with delamination now, then the build quality is good enough to have prevented build issues with the composite (e.g., corners separating with use). So now, you really just have to do regular maintenance to prevent seam leaks, etc., that can result in delamination.

[Optimistic_Para]

Bumpyroad wrote:
I'd be more concerned with a metal sided unit going thru a hail storm which is more likely than a lightning strike.
bumpy

Let's be clear. The latest figures I've seen suggest that less than 20 people died from lightning strikes in the US last year, and all of them outside. However, it's estimated that 9 out of 10 people struck by lightning survive, but are injured to various degrees. Which suggests that maybe 200 people in the US are hit by lightning every year.

The original poster asked for differences between metal and fiberglass, and protection from a lightning strike is certainly one of them. How much WEIGHT we should give to that fact is something each of us needs to decide for themselves.

[theoldwizard1]

WNYBob wrote:
IMO Fiberglass is not worth it, unless the backer is NOT WOOD. Yes most "fiberglas" RV's have wood as a backer. Even high humidity or a very minor moisture penitration can cause "Delamination". If this happens you loose THOUSANDS in resale value.

Look for Azdel or similar non wood backers.

I could not have said it better ! Azdel is the only "backer" that does NOT contain wood/wood fibers or other material that will rot. Only a couple of RV companies use it (Coachman for one) and it is NOT used in all exterior surfaces.

[sleepygeek]

Most fiberglass TT and motorhomes are made out of "composite" walls. Some kind of a "backer" and then a piece of fiberglass with resin. This design is usually placed in an oven that melts the resin so that it adheres the backer. Pressure may or may not be used. If the backer get wet, the fiberglass can delaminate.

It may be this type as in the above quote. Smooth flat sheets on the sides, I'll check to see if it has backing glued to. Over cab part looks molded

[Bumpyroad]

I'd be more concerned with a metal sided unit going thru a hail storm which is more likely than a lightning strike.
bumpy

[toedtoes]

I believe the concept is that the lightning will strike the tallest thing (it strikes if it gets within 150ft of a positive charge), then that being equal, the thing with the strongest positive charge. So if you have two RVs, one fiberglass and one metal, side by side and of the same height, the lightning will hit the metal one first.

Things like antennas and ACs, etc., will make the real world behavior more complex, because it connects a potentially lower positive charged item to the lightning first.

[Optimistic_Para]

troubledwaters wrote:
If you are inside the trailer there is no path to ground, the lightning ain't going through you (or your non-conductive fiberglass trailer); it's going to hit the metal trailer next to you (the much easier path to ground).

Can you provide some scientific source to back up your claim that lightning won't hit a fiberglass trailer because it's non conductive? Cause it certainly hits wood houses, and wood ain't particularly conductive.

[troubledwaters]

If you are inside the trailer there is no path to ground, the lightning ain't going through you (or your non-conductive fiberglass trailer); it's going to hit the metal trailer next to you (the much easier path to ground).

[Optimistic_Para]

sleepygeek wrote:
Would a Heavy chain dragging from hitch be any help to disperce the lightning charge, the walls and floor have a 2 inch square tubular ridged frame spaced about 4 feet apart ( vertical+ horizontal ) as in a cage, connected to the truck frame. Would this not be of any help against lightning.

I'm not an expert on this. Everything I've ever read on this subject says that it's the metal SKIN of the vehicle that carries the electricity AROUND you and into the ground, right through the rubber tires. absent that metal skin, I would guess the lightning could pass right through you and then get carried into the ground via this heavy chain. Which would kill you.

Vehicles and Lightning

https://www.weather.gov/safety/lightning-cars

[toedtoes]

I believe your motorhome is a molded fiberglass shell, not the current fiberglass panel type. They do not delaminate like the panel type.

My 43 year old clipper is a molded fiberglass shell.

The main consideration is if the seams are on the corners or offset. If offset, then you are in good shape as the fiberglass shell is unlikely to leak at the seams. That leaves only the cut outs (windows, AC, etc.) sensitive to leaking.

The aluminum sided motorhomes are much more prone to leakage as they were usually built using multiple panels per side and had seams on the corners. Each seam and panel change is a potential leak.

The fiberglass shell will look nicer than the metal - allowing you to get into RV Parks that use 10 year old limits to keep out people they see as "trash".

Outside of that, your main concern is the quality of the house and chassis/engine. For a 30+ year old rig, those have more to do with upkeep by prior owners than manufacturer.

[WNYBob]

IMO Fiberglass is not worth it, unless the backer is NOT WOOD. Yes most "fiberglas" RV's have wood as a backer. Even high humidity or a very minor moisture penitration can cause "Delamination". If this happens you loose THOUSANDS in resale value.

Look fot Azdel or similar non wood backers.