What wood type did you use in your teardrop build?

[goteardropgo]

And why?

Here's what I'm doing...
1. For the wood touching the frame I'm using to support my trailer platform I've used poplar (1x3 strips).
2. For the platform I've selected some 3 ply pine plywood sheets (I think this is 1/2" which I will glue and staple to the poplar strips.
3. For the floor I'm going to glue & staple 1/4" Ash plywood to the plywood platform.

For my walls I plan to use 3/4" pine plywood as the frame, a thin sheet of pine for the outside face and a thin sheet of Ash for the interior facing wall.

For the roof/ceiling I plan to use 2x2 strips sandwiched by a thin sheet of flexible ply (roof) and a thin sheet of Ash for the ceiling.

I plan on skinning the whole box in Aluminum sheet.

Questions:
1. How thick should my thin sheets of wood need to be so I can wrap them around curves (like the roof/ceiling shape of a teardrop)?
2. How "thick" should the walls be for standard sized rv doors and windows to be installed?

Thanks All!!!

[halfdome, Danny]

I used 3/4” Pacific Birch Light plywood for my walls and floor.
It’s lightweight and has multiple layers.
I covered the floor with plastic laminate (plam) on both sides and bolted it directly to my chassis.
I covered the interior walls with 1/8” Red Oak plywood.
The ceiling is a nice looking sheet of 1/8” Baltic Birch plywood.
I covered the walls and popular roof spars with 2 layers of 1/8” Baltic Birch plywood making sure to glue and staple over the previous seams.
The galley walls, lid interior and bulkhead are covered with plam.
My interior wood is Red Oak and Walnut.
The galley cabinets are Macacauba and walnut.
I glued down the .032 anodized aluminum with contact cement.
Danny

[lfhoward]

My wall has a stick built 1x3 skeleton of select pine (pricey but straight grain and unlikely to warp) held together with Titebond II & pocket hole screws. The outside is 1/4” pine plywood, coated with spar varnish and skinned in aluminum. The inside is 1/4” thick knotty cedar. In between the skeleton is 3/4” styrofoam insulation. Total wall thickness: 1-1/4”. I went a little heavier than normal because I have an off road build. You could get away with poplar instead of pine and 1x2’s instead of 1x3’s for a highway build. You could also use 1/8” ply for interior walls. For the wall skeleton you could also cut polygons out of 3/4” ply instead of making it stick-built.

[noseoil]

Bottom panel is 3/4" thick poplar frame with 1/8" Baltic birch for the top & bottom (bottom has 2 coats of urethane & 2 coats of Henry's white roof coating); side frames 3/4" plywood skeletons with 1/8" Baltic birch inside & outside; top headliner is 1/8" Baltic birch covered in raw canvas & bent into the rabbet; 3/4" foam insulation inside the skeleton & (2 layers) in the ceiling, then skinned with 1/8" Baltic birch (Hmmm, seems to be a pattern here) coated with urethane & skinned outside with .040" aluminum. See build log for instructions & pictures...

[tony.latham]

Questions:
1. How thick should my thin sheets of wood need to be so I can wrap them around curves (like the roof/ceiling shape of a teardrop)?
2. How "thick" should the walls be for standard sized rv doors and windows to be installed?

If I couldn't get 1/8" Baltic birch for the headliner and roof, I don't know what I would do. That stuff is strong and likes to bend.

For your second question, it depends on the trim rings. I buy my windows (and in the past doors) from Vintage Technologies, if you purchase from them, they can answer that question.

I had to add a 3/8" piece to my doors to get the window trims to work but I knew that when I cut the order. I wanted my walls 1/4", 3/4", 1/8".



Tony

[tony.latham]

Chip board from my county land fill...

Hey, Slow! They shoot looters at our dump!

Tony

[Tom&Shelly]

Chip board from my county land fill...

Hey, Slow! They shoot looters at our dump!

Tony

Wood is the one thing they let us scrounge at ours. Our neighbors are pretty good scroungers though--pickings are generally pretty slim.

Tom

[Tom&Shelly]

If I couldn't get 1/8" Baltic birch for the headliner and roof, I don't know what I would do. That stuff is strong and likes to bend.

Tony

Second that: It's great stuff, and in our area costs less than $20 per 5 foot by 5 foot sheet, for 1/4 inch and 1/8 inch thick sheets. Cheaper than 1/4 inch AC ply.

Our walls are 1/8 inch Baltic birch inside, 3/4 inch AC ply skeleton (foam filled) and 1/4 inch Baltic birch outside. Our ceiling and roof are each 1/8 inch Baltic birch with 1 1/2 inches of foam (and struts) in between. 4 oz fiberglass and epoxy covers the outside. We bought our doors from Challenger designed to fit the 1 1/8 inch walls.

Tom

[tony.latham]

Our walls are 1/8 inch Baltic birch inside, 3/4 inch AC ply skeleton (foam filled) and...

I think when people see that 1/8" number it probably scares pre-builders. I think it needs to be qualified as to what we're really talking about.

My roof/ceiling consists of 2 sheets of 1/8" Baltic sandwiched over 2" of XPS foam. It's a foam-core torsion box.

This summer, I ran over a sheet of 3/4" poly foam board with my Tacoma wearing semi-aggressive tires. I could barely see a tire impression. Except for the edges, had it been sandwiched with 1/8" Baltic, there may not have been any perceptible damage.



Tony

[goteardropgo]

Wow, thank you for all the comments. Really helpful. The replies have given me a lot to think about. But they also have built my confidence. Seeing some folks using thicker insulation has got me thinking this maybe a nice thing to consider. Especially in the ceiling.

Anyone have an opinion on insulating the floor vs. just using the wood? I've seen some builds sandwich insulation in the floor and others don't.
Anyone have trouble with bending? Someone commented about the bend ability of Baltic Birch.

My design has a pretty aggressive bend at the front. Should I be worried?

[tony.latham]

...got me thinking this maybe a nice thing to consider. Especially in the ceiling.

The spar depth drives my ceiling thickness.

Anyone have an opinion on insulating the floor vs. just using the wood?

My recent floor is 1/4" ply on the bottom and 1/4" ply on top. It has a framework that is 3/4" internally. The voids are filled with foam board for support. It's plenty strong.

On top of that floor is 8" of dreamy foam. If you really need insulation in a teardrop floor, I think you don't enough mattress.

Tony

[Tom&Shelly]

My design has a pretty aggressive bend at the front. Should I be worried?

My front has a 19 inch radius, and it wasn't much of a problem for the 1/8 inch Baltic birch. If you find a place that has it in stock locally, you may want to buy a sheet to experiment--it's not expensive.

BTW, it comes in 5 foot by 5 foot sheets for cheap. I've also seen it for sale in hobby stores in little pieces at much higher prices. I remember my Dad using it (or some sort of plywood that's very similar) in model airplanes for the firewall. I think he paid as much for a 12 inch by 12 inch piece as I've paid for an entire sheet (adjusting from 1970's dollars to 2020.) If you have a hardwood plywood lumbar yard in your area they may carry it.

Tom

[goteardropgo]

Thanks for the reply.

Platform has been built. I used 3 ply pine plywood for the surface facing the ground. I used 3/4 x 3 inch poplar strips for support and 1/4 Birch ply as the top surface of the platform. I installed 3/4 foam insulation in the gaps. I used wood glue and staples to sandwich all of it together. Seems strong enough and yet without the weight. Since my bed will actually rest on top of the platform (because it sits on my fenders) I can get away with a much lighter platform build.