How thin should the Aluminum outer skin be?

[nomad]

Hi all,
Bear with me, as I have experience at all!
I am not sure that I ask the right question ,but here is my dilemma. I am trying to build a small and light trailer, so I can pull with my motorcycle.
The top outer skin is my problem. I cannot find any Lauan plywood at my local, and I am not sure that Lauan plywood is the best material to go with. I am thinking about Aluminum skin (both side panels are wood), and i have no experience to know what thickness of the sheet that is good enough to use. Of course, I like to use lightest material, but durable, so I think Aluminum is the way to go.
Any info, or suggestion will be appreciated.
Nick

[ssrjim]

Get the thinnest they got. Plenty strong and easier to bend.

[nomad]

Get the thinnest they got. Plenty strong and easier to bend.

Thanks for the quick response. After I post the question, I realize that I may not explain clear enough that my "outer skin" is also the outer layer. Behind the outer skin (outer layer), I will install a layer of insulation, then maybe a very thin and light cover material.
Should a 0.032" thick alu. sheet be a good enough outer layer?
Thanks again!

[webbaldo]

Just bare in mind if you don't use something like 1/8 ply behind the aluminium, it'll be a lot more prone to getting dings/dints etc., even just pushing the trailer might crumple it.

I used 1/8 plywood then 0.9mm Alu skin (not sure what that is in inches)

If you really cant use a ply under skin, a really firm foam insulation maybe would compensate a little?

Of course it it's a really little trailer, you could get away with it (as in a few ft)

Maybe someone who hasn't used a underskin could offer some better advice?

Have a look through the Hall or Fame, It answered 100's of questions for me before I even started planning

[Kharn]

Anywhere you can get plywood should be able to special-order luan if they do not regularly carry it.

[nomad]

Just bare in mind if you don't use something like 1/8 ply behind the aluminium, it'll be a lot more prone to getting dings/dints etc., even just pushing the trailer might crumple it.

I used 1/8 plywood then 0.9mm Alu skin (not sure what that is in inches)

If you really cant use a ply under skin, a really firm foam insulation maybe would compensate a little?

Of course it it's a really little trailer, you could get away with it (as in a few ft)

Maybe someone who hasn't used a underskin could offer some better advice?

Have a look through the Hall or Fame, It answered 100's of questions for me before I even started planning

Thanks much for the tips.
As I have mentioned before that I have no experience, I've recently learned that Aluminum alone will not be practical as it will collect moisture inside. I think I will have to go with thin plywood panel.

[nomad]

Anywhere you can get plywood should be able to special-order luan if they do not regularly carry it.

I have tried my local Homedepot and Lowes, and they both cannot order lauan for me.

[ssrjim]

The way I build my walls.

Start with 3/8 sheathing ply wood.
1x2's stapled and glued to the plywood about every 10 inchs
Fill the voids with rigid foam insulation
A nice veneered 1/4 plywood on the inside
Cover the outside with aluminum

[Rainier70]

Go to a trailer sales lot and look at how cargo trailers are made. Ask them on the skin gauge etc.
On cargo trailers there is just the alum skin, framing and an inner plywood layer. The inner plywood layer provides the strength between the framing. You don't want to seal the outer layer too much. Use foam insulation and a vapor barrier on the inside. Venting on the bottom sill plate towards the outside would do.

Yes, it will dent or ding. On a cargo the front is protected with a layer of plywood under the alum skin and they also usually have a piece of diamond plate on the bottom 2 ft of the front. Corners are a heavier material.

[milliejohn]

Hi all,
Bear with me, as I have experience at all!
I am not sure that I ask the right question ,but here is my dilemma. I am trying to build a small and light trailer, so I can pull with my motorcycle.
The top outer skin is my problem. I cannot find any Lauan plywood at my local, and I am not sure that Lauan plywood is the best material to go with. I am thinking about Aluminum skin (both side panels are wood), and i have no experience to know what thickness of the sheet that is good enough to use. Of course, I like to use lightest material, but durable, so I think Aluminum is the way to go.
Any info, or suggestion will be appreciated.
Nick

if you don't mind the rivets, use aluminum roofing rolls found at all home improvement stores, you can trim with tin snips and shears, and if you get a bad blemish from use/accident, just unrivet and re install new piece. easy to try out on a piece of plywood to see if you like results before doing the trailer, type of rivets and size is up to you. The trailer in my signature was recovered in .063 skin from a 1947 donor trailer, 1/8th inch rivets and silicone caulked, no leaks after 1000's of miles off-road.

[Kharn]

Anywhere you can get plywood should be able to special-order luan if they do not regularly carry it.

I have tried my local Homedepot and Lowes, and they both cannot order lauan for me.

They may not call it lauan/luan, as that denotes a specific tree, but it should be available as 5mm (or possibly 1/4") moisture-resistant underlayment, it is commonly used under vinyl flooring.

[nomad]

Thanks so much guys, for all the info and tips.
I finally decide to use the 1/4" plywood for the top. Based on my "no experience" knowledge, I will cut the panel into two trips of 20.1/2" wide, so I can bent it. Talking about bending plywood, I have never done this before, so everything is still up in the air, but I will try hard.
I hope I can finish this project in the next three months, so I can pull it across the country trip (~8000 miles).
My biggest hurdle is the door, and I have no plan (design) to build one, and I have not found a place to buy a premade one either. The door should be simple, rectangular. Also, the trim is another hurdle that I don't where I should start; Aluminum is probably too hard for me to learn, but what do I know!
Any direction will be appreciated.
Nick

Below is my first prototype cut. Please let me know what you think about the shape, fine? ugly? need to trim the top?

[GuitarPhotog]

If you're towing it with a bicycle, wind resistance won't be much of an issue. You won't be going fast enough for it to matter. Weight will be more of an issue, going downhill as much as up.

You might consider fitting a tandem style "drag brake" on the trailer for those long downhill runs. An extra couple of hundred pounds behind a bike with rim brakes on a long down grade may become problematic. I've had tires come off the rim of my tandem because of brake induced rim heating.

Base your shape on minimum materials, and therefore minimum weight. I'd go for aluminum over 1/4" ply. Easier to bend and probably 20-30% lighter. Don't worry about the aluminum denting, as long as it keeps you dry, a few dents never hurt anybody. My all-aluminum trailer is 65 years old, and like its owner it has a few dings and dents. They don't affect how well it tows or how well I sleep in it.

I'd be really concerned about every extra pound of weight because as a wise old bicyclist once told me "on the scale of a bicycle, the world is far from flat."

<Chas>

[webbaldo]

Thanks so much guys, for all the info and tips.
I finally decide to use the 1/4" plywood for the top. Based on my "no experience" knowledge, I will cut the panel into two trips of 20.1/2" wide, so I can bent it. Talking about bending plywood, I have never done this before, so everything is still up in the air, but I will try hard.
I hope I can finish this project in the next three months, so I can pull it across the country trip (~8000 miles).
My biggest hurdle is the door, and I have no plan (design) to build one, and I have not found a place to buy a premade one either. The door should be simple, rectangular. Also, the trim is another hurdle that I don't where I should start; Aluminum is probably too hard for me to learn, but what do I know!
Any direction will be appreciated.
Nick

Below is my first prototype cut. Please let me know what you think about the shape, fine? ugly? need to trim the top?

1/4 plywood might be bugger to bend mind, compared to 1/8.

Love the shape!, should look good when finished!