Outside Wall Composition?

[Francesca]

Hi, All you trailer/motorhome restorers

I'm posting this in the Vintage Forums hoping somebody will recognize this material and tell me how long it's been in use, or even IF it's in use!

Is this the material that most fiberglass-sided trailer and motorhome outside walls are made of now? If so, does anybody know why it's not just plain fiberglass like on my '78 trailer?
Am I looking at some kind of gelcoat/fiberglass/particle board/veneer sandwich???

Thanks!

Francesca

[ahicks]

Yes?

[ga traveler]

Great shot. This shows why delamanation is a hard problem to repair. The plywood is affixed to the fiberglass for strength. When water gets on the plywood, it causes the plywood to go to pieces. the fiberglass is not rigid by itself. When the plywood is gone, the fiberglas gets wavy. That is why you can't shoot glue in a hole and repair delam.

[Francesca]

Thanks-

This is a hard concept for me to grasp since I have a molded fiberglass trailer that isn't sandwiched like that.
Is using the wood to add thickness just cheaper than thicker fiberglass???
And does this practice go back a long time?
Seems like a really major thing to look at/for if one is shopping for used RV's...

Francesca

[QuietWater]

This is why I picked a Holiday Rambler. I took this picture at a salvage yard but it shows what is underneath the aluminum siding of an HR. I didn't want the delam problem or rotting wood frame. Been there, done that.

[Francesca]

Wow- that's a great inside/out picture- Thanks, Quietwater!

I don't see any wood at all...it looks like all aluminum and galvanised steel.
Am I looking at the exposed inside wall to the left of the picture?
Is that the rear of the rig with the exterior siding off?

Thanks again

Francesca

[ga traveler]

Quote:

Originally Posted by Francesca Thanks- This is a hard concept for me to grasp since I have a molded fiberglass trailer that isn't sandwiched like that. Is using the wood to add thickness just cheaper than thicker fiberglass??? And does this practice go back a long time? Seems like a really major thing to look at/for if one is shopping for used RV's... Francesca

This is what they call in the business a western wall. It was invented in the western states.The plywood is used to keep down the weight. Fiberglass is heavy. They use a light wood for the plywood. If you remember the first fiberglass motorhomes, they were corrogated for strength.

[ga traveler]

Quote:

Originally Posted by Francesca Wow- that's a great inside/out picture- Thanks, Quietwater! I don't see any wood at all...it looks like all aluminum and galvanised steel. Am I looking at the exposed inside wall to the left of the picture? Is that the rear of the rig with the exterior siding off? Thanks again Francesca

The wood is next to his thumb.

[ga traveler]

Quote:

Originally Posted by ga traveler The wood is next to his thumb.

Sorry, I misread your post. I thought you were referring to the first picture.

[Francesca]

Quote:

Originally Posted by ga traveler This is what they call in the business a western wall. It was invented in the western states.The plywood is used to keep down the weight. Fiberglass is heavy. They use a light wood for the plywood. If you remember the first fiberglass motorhomes, they were corrogated for strength.

Thanks!
So that's the way they're all built nowadays?
How far back would one have to go to find a rig with straight fiberglass, no wood lamination?

Francesca

[QuietWater]

The front and rear of an HR are a fiberglass shell. The unit in the salvage picture had the shell removed. You could see the inside luan wall. If you ever wondered what the roof was composed of, here is a picture of that, too.

Quote:

Originally Posted by Francesca Wow- that's a great inside/out picture- Thanks, Quietwater! I don't see any wood at all...it looks like all aluminum and galvanised steel. Am I looking at the exposed inside wall to the left of the picture? Is that the rear of the rig with the exterior siding off? Thanks again Francesca