Need help deciding on wall construction method.

[mattiker]

I have finally found a decent donor trailer, and will be building my first teardrop. I have a couple of shapes that I'm thinking about, but want some help deciding on the best method of wall construction. It's worth noting that I plan do exterior waterproof using PMF. So far, I know of:

Just straight up plywood, generally between 1/2 in and 1 in. Strong but heavy, can jigsaw out bits and fill with insulation for weight savings. Fast.

Foamie walls, being glued together with gorilla glue or alternative. Light, but watch out for tree branches. Don't know how well PMF will stick/stay. Kinda fast.

Framed construction: use biscuits or screws and 1x1, 1x2, etc to frame the walls. Fill the gaps with board insulation and affix 1/8 inch plywood to exterior. More work.

In short, I'm trying to determine which of these is the best compromise between cheap, light, and strong (in that order). I'm leaning towards minimal framing (1x1s for border and supports to windows/door/galley) to add some strength to 1 inch 4x8 XPS foam boards with a very thin exterior piece of plywood for the TBII to stick to. Thoughts?

[halfdome, Danny]

My first TD was 3/4" wood framing with 3/4" foam board and 1/2" Baltic Birch Plywood, quite heavy and way too much work.
My second to sixth builds were 3/4" Pacific Birch Light plywood ( 48# a sheet ) and for a 5' x 10' with 2 batteries and a tongue box they ended up at 1420 #, very easy to pull with my Chevy Trailblazer and only loose a mile or two on gas mileage.
Foamies, in my opinion, are way too light and scare the daylights out of me.
Your trailer is suppose to be able withstand a 35 mph side wind, the same as a 18 wheeler crossing your direction on a 2 lane highway.
Do as you wish, Danny

[eLink]

I had been struggling with the same question. But I keep leaning toward solid 3/4" birch ply. It's only about 14 lbs. heavier than the sandwiched method (per side), and should be a lot easier to construct.

SolidWall.jpg (67.95 KiB) Viewed 4489 times

SandwichWall.jpg (133.03 KiB) Viewed 4489 times

[tony.latham]

Foamies, in my opinion, are way too light and scare the daylights out of me. Your trailer is suppose to be able withstand a 35 mph side wind, the same as a 18 wheeler crossing your direction on a 2 lane highway.

I have to agree. We were headed to Chaco Canyon last month when we managed to get cell service 16 miles north of Shiprock and snatched the weather forecast. It was predicting gusts to 70. Ouch.



We turned around. I think Flash, our sandwich-walled 'drop would have been fine, but not an ultralight trailer.



Tony

[John61CT]

"Too light" ?

wrt the upper "pod" / skin specifically, that is IMO not a thing, as long as it is strong enough for 70+ wind forces from any direction.

Which I believe foamies **can be**, very flexible definition that, strategically placed framing is certainly part of the genre afaic.

The lighter upper gives the ability to build not only a proportionally stronger suspension / chassis, but also

allows you to install more water, propane and battery bank and arrive at the same total weight, at a much lower CoG.

With of course a very solid connection between the upper pod and the base chassis frame, that's critical.

[aggie79]

One of my all-time favorite teardrops on this board - Gaston's Snuizer - was a pseudo-foamie design before there even was a foamie category on this forum. It did have an interior wood structure. Instead of PMF, the exterior skin was fiberglass.

[greygoos]

AGGIE79 - QUOTE
One of my all-time favorite teardrops on this board - Gaston's Snuizer - was a pseudo-foamie design before there even was a foamie category on this forum. It did have an interior wood structure. Instead of PMF, the exterior skin was fiberglass.

Didnt that Teardrop roll over?

[saywhatthat]

[attachment]

Picture 460.jpg (103.53 KiB) Viewed 4294 times

I can not see building anything that could rot . like skeleton frame

[Tomterrific]

The strenght of the camper will be the wall to roof joint. 1/4 " with a strong joint will be stronger than 3/4" with the roof just laid over the top of a wall. Surface area is the key. Make sure your floor to wall joint is also strong.

My suggestion is to use 1/2" walls and cleats made from the same size wood as the ribs for the roof. The floor would have boards attached around the edges, and across, for the sides to attach strongly. This gives a wide enough glueing area for great strength. Just like building a boat.

Everything I have mentioned is common procedure. Insulation is needed in the roof, not so much in the walls or floor.

Tt

[rkanz]

I used 1/2” marine ply for walls with 1/4” birch ply for the top. There are 3/4” by 1 1/4” blocks in the corners. Very strong construction and light. My trailer weighs 600 pounds.


Sent from my iPad using Tapatalk

[tony.latham]

I'm finding this thread a bit humorous.

Wall construction is a contentious subject.



Tony

[Tomterrific]

Not contentious, I would say there is more than one way to skin a cat (camper?)! :-)

Tt

[StrongFeather]

Carbon Fiber is the way to go!

Only if you’re crazy, that is.


Steve


Sent from my iPhone using Tapatalk

[tony.latham]

[working on it]

AGGIE79 - QUOTE
One of my all-time favorite teardrops on this board - Gaston's Snuizer - was a pseudo-foamie design before there even was a foamie category on this forum. It did have an interior wood structure. Instead of PMF, the exterior skin was fiberglass.

Didnt that Teardrop roll over?

* Yes, it did, back in 2009. Here's a link to that thread http://www.tnttt.com/viewtopic.php?f=2&t=32474