First timer build and questions

[dancam]

Hello everyone. I am brand new to this site. Never built a trailer before. I helped repair write-off RV's when I first started in the autobody trade but I do not remember it well and just did what I was told at the time. I am making a 30,000km trip touring all of Canada as well as Alaska next summer with my wife and 2 kids. I had a trailer planned, It was going to heavy and I was looking up how to do my canvas for it and came across this site monday. I have since scrapped those plans and now I believe I want to build a pop-up foamie after this style: http://www.goldbrand.info/motorcykelhusvagn2.html
Now, I have tried to read as much as I can since monday but I am brand new to all this. Problem is I need to have this built by the end of summer, preferably by the middle of September to test behind the tow vehicle while its still warm. If its not done by then it absolutely has to be finished by the middle of october. I was originally planning to start building a rough mock-up out of cheap osb next week to test out different front and rear designs for aerodynamics, finalize the design by June 22 and have all my materials sourced and bought by the end of the month. Thats probably not going to happen now, but I have a short timeline for doing something I have never done before. I have no garage or indoor place to work in at home and I will be working on the tow vehicle and buying supplies for the trip in the winter. The car will be recieving many modifications and upgrades to prepare it for this trip. We are doing a test run with the trailer, car and all supplies may long weekend next year, making any changes we need to and then leaving leaving middle of June.

Anyhow, I can describe the trip and tow vehicle more later, I need to get the trailer planned now and I am hoping for some help. I will quickly outline my old plan, and why I was going to do what I was, then describe what I am hoping to build instead.

I decided on a 5 foot wide trailer because the TV rear bumper is 5 feet wide. Kind of keeps the wind drag down a bit and I won't have to think so hard about where the trailer is while driving and sightseeing. Looked at 8 foot long ones and liked them for their size and weight. Then looked at it more and realized that there isn't enough room for 2 kids to sleep in there with us or enough room for what we want to bring. So we have to go with 5x10. I had an idea to make a trailer where the roofline was even with the festiva roofline to cut down on wind drag and have it pop up quick from inside to use when stopped. My ideas for that was a lot of building, bit heavy, and takes time to set up and take down every time. Also less storage space. So I rented a covered u-haul trailer that was 8ft long, 5 feet wide and 5ft high inside, 6ft6in high from ground to roof. I did that to see how the festiva (my TV) would pull a covered trailer, as there is a lot of wind drag. Most covered trailers are taller than that though, so this has less drag than what I would end up buying- However most regular trailers are lighter than the u-haul. The 5x8x 6.5 tall inside dimension ones i looked at were 800 pounds and this shorter u-haul is 900 pounds empty.
I picked it up with my 2002 honda civic, The civic hated it. Once home I parked it and hooked up the Festiva thinking there is no way this is going to work. I filled my festiva up with weight, 5 gallon jugs of water, a transmission, all sorts of tools, steel rims... and hooked up the 900 pound trailer. To my suprise the festiva pulled it almost as well as the civic! I was shocked, the civic has 115 hp, almost double my festiva, yet the Festiva pulled almost as well. Then I got my bigger suprise, I believe it stops the trailer faster than the civic! At the very least just as fast. And i have all brand new drums, rotors, pads and shoes on the civic. Couldn't believe it... Both cars were quite stable if i jerked the wheel around or swerved at 60mph. I drove quite a ways to find some big hills, 4th gear is adequite up most, keeps it above 52-54mph, but on the steepest ones it runs out of steam pretty quick in 4th. If i shift into 3rd at 50mph I could still speed up up any hill I found, even if just slightly, I was still speeding up. I went a couple hundred kilometers, then brought it back to u-haul with my festiva, did 70mph on the freeway no problem.
So, the festiva normally gets me 50mpg at those temperatures (52-54 in summer) and it dropped to 30.25mpg with the u-haul. Thats pretty good considering I had it floored most of the time in 5th and had it in 4th and 3rd a lot just doing the biggest hills we have within an hour radius around here. That is a 40% drop in fuel milage. My civic however only towed it home on the flat and it normally gets 44mpg and that dropped to about 21.5mpg, a 50% drop! I may as well drive a pickup with an extended bed for that kind of fuel milage... Anyway, I also took my 4x6 trailer with short sides and loaded it up with about 900 pounds total. Then i put a piece of plywood on the front that was 5 feet wide and as high as the roofline of the festiva. It was harder to tow than the u-haul, I got 29.6mpg with it after several hundred km. On the way home with it I pulled over and removed the plywood from the front of the trailer. After that it was still noticable that I had the trailer to speed up and slow down but cruising was exactly the same as with no trailer, exact same reading on the vaccum gauge as empty driving to work. So all that was slowing me down before was wind drag, just a piece of wood sticking up like that is worse than a long box.

I read some about trailer aerodynamics, looked at how to build them better a bit and decided we had to go with a shorter in hight trailer, it will be way easier on the car and myself while driving on this trip. Also at 30mpg and fuel at $1.15/L its $3400 on gas. If I get it up to 40mpg that saves me $900-1000 in fuel as well as being easier on the car and my attention, noise level is lower with less time spent in 4th and 3rd gear... I could pull a full size enclosed 5x10 but I dont think i want to. It would be so nice for no set up or take down time, but I dont think that outweighs the disadvantage of drivability. Also it would catch more crosswind.
So I had been looking at trailers back in december and they were fairly plentiful and cheap. Now there are not very many and they are pretty pricey. Not many people selling them for much less than new price and I want one that is as light as possible, there are lots of heavy ones out there.

I bought a new lightweight 5x10 trailer. I was going to build sides on it that are 3ft 6 in high with a split at 2 ft up the side so there is 2ft on the bottom half and 1.5ft on the top half. I want the roof of the trailer to be even with the roof of the car while lowered. Then I wanted to be able to lift up the top section and stick kind of legs in there so That we can stand up in it. I think I am 5ft10 and my wife is 6ft, so they would have to be about 2ft 6ish tall. Then I was going to have had some type of canvas attached to between the top and bottom halves that would fold up into a little shelf thing on the outside of the trailer when its lowered. On the inside I will have a 20.5inch space down the length of each side for storage, 2 feet at the front. That leaves 18 inches in the middle for walking. I would put plywood 2 feet high to divide the storage areas to keep everything neat. Then have 5 ft long 1x4 bed slats that could be stored somewhere while towing, but to sleep would lay overtop of plywood storage divider sides and we could inflate the air mattress on top of it. On the front of the trailer I will build something for better aerodynamics and it will house the spare tire for car and trailer, battery and probably the showering unit. A cubby near the axle only accessible from the outside and airtight to the inside for storing the propane and a gerry can of gas. I want to weld some kind of jacks to the back of the trailer for leveling so it doesn't rock much while sleeping at night. I planned to frame it with 2x2's and use probably 1/4in plywood on the outside. Then glue 1/16th thick plastic to the outside for protection and waterproofing. I can get 4x8 sheets for $15 I think.
I havent figured out to well what I will do on the back of the trailer. For aerodynamics you kind of extend the sides past the actual back of the trailer, reduces drag a lot. I can do that then attach some type of screen or canvas tent-like stuff to the inside of it to extend our bug and rain free trailer useage area. I also need to bring our bikes somehow, thought of attaching the bike rack to a receiver i could build in the back of the trailer, then moving it to another receiver on the side of the trailer when parked but then if its raining when we stop thats a pain to move. I really dont know where to put the bikes yet.

Inside the trailer we need to store all our cooking gear, stove, utensils, pots, toaster and all that. We need at least 2 coolers to store food, one if not both will be powered. Water for drinking as well as jugs to hold shower water. Diapers for the kids Clothes for all of us, enough for a week including warm clothes, raingear... (temperatures can range from 32f to 105f, snow, rain, sun wind and bugs over these 3 months where we are travelling). Inflatable boat, motor, lifejackets and paddles. 25 pound Propane, 20 litre gerry can of gasoline. Air matress, sheets, matress topper, pillows, kids matresses, electric air pump. Folding chairs, kids toys, towels and soap for showering. Thats a fair bit of stuff...

I am planning to run wires with dc power from my car battery to the battery in the trailer. Then have some dc outlets in the trailer for chargers, electric air pump, powered coolers and stuff. I will keep all the lights in the trailer 12volts. I will also run 120v ac power from the inverter in the car to the trailer and probably just have one outlet for whatever we might need in there.

I weighed a whole bunch of stuff, and that plan for the trailer build came to about 970 pounds, then everything I want to put in it is about 900 pounds. I need to keep the trailer to 1700 pounds max so I was trying to come up with what I could all take out when I found out about foam trailers. Building this with foam should allow the trailer build to be lighter and be more convenient than my canvas idea.

On the front I want to do something to connect the car to the trailer and get rid of the car-trailer gap. Havent figured that out yet.

I have no idea how I will do the rear door since this thing splits in half.

Old trailer plan:






Profile of back of Tow vehicle


Uhaul


New trailer I am using for the build


I want to test out this type of design on the rear and see what it does


Then between the car and trailer I want to block the gap something like this and do something similar on the wheel wells.







Anyhow, that was my plan. Now for the new plan. The trailer i bought is supposed to be 700 pounds. I haven't weighed the axles yet. The wood decking is 360 pounds if you calculate the weight of treated lumber for 50 square feet. Take 40 pounds off that for gaps and just to be safe and we have 320 pounds. I am cutting the ramp off for sure and probably the sides and I guess them to total 70 pounds. That leaves me with a 310 pound trailer. I was thinking exterior plywood on the floor, the wood glue and canvas over styrofoam for the sides and roof. A wood frame in it especially on the bottom to attach the dividers to and to have something to rest the top half on that is supportive enough. Then a front aero panel that will house the tires and stuff. The deck hight of the trailer is 14 inches, so that leaves me with 3ft 6in to work with for hight on the trailer. I do not know what I am doing for the door on the back. I will manually raise and lower the top section. I calculated the water we would need to bring for cooking, cleaning and drinking for 3 days. Its a lot. Also want to be able to fill another tank and go shower. Looking into water tanks for under the trailer. This is on a tighter budget.
I have a bunch of questions. I am reading as much as I can on this site, but need to get started real quick and hate to do things without a solid plan. If there are other builds I should read through or articles that answer my questions please attach them in this thread, I would appreciate it very much! I will start another thread about our trip plans if there is interest in that later.
So, my questions are:
-Will the foam be strong enough and will the trailer last 30,000km and 3 months of continuous use? I see people saying these trailers are strong but then are happy with how long they lasted when they leak after 5 years...
-Is foam and canvas optimal for what I want to do? That being light, cheap, durable enough. I have some equipment at work I will picture below that I can use to laminate other stuff.
-how do I seal the top part to the lower half to be bug proof when it is raised and we are sleeping?
-should I rest the top part on the trailer deck when its down or on the top of the lower half?
- Is there a completely different style of trailer that would work better for what I want?
- I want to close the car-trailer gap but have an aero front in case that breaks or fails. Suggestions? That spandex and velcro does not stretch enough to turn sharp. I saw thin plastic attached to the TV and on recessed spring rollers on the trailer suggested. My idea was spandex/canvas/tarp attached with velcro to the rear hatch of the TV and either good quality bungee cords keeping it taut to the trailer or spring rollers and cables. Any other suggestions?
-I am going to start looking through the section of the forum entitled 'skinning secrets', but is there one particular article that explains it well? like I said, I found this site 2 days ago...
-I am wide open to any design modification suggestions! As long as it fits in with this trip- 30,000km in 3 months behind a 63hp car with 2 adults, a 4yr old and a 2yr old.
-How strong does just plywood with minimal framing get when your do the glue and canvass? is that better?
Thanks!



At where I work we have a CNC router table. It is 7ftx12ft. The spoilboard on there now is just bigger than 4x8. Materiel is held down by that huge vaccum pump on the floor on the left. We cut a lot of custom sized shower floors with it. Quite similar to this actually. Cut the floor to any shape, size, slope you want and then cover each side with fibreglass so its strong enough to drive a truck over, drop it in and tile your shower.

Router


Also We do a bunch of vaccum forming.
Vaccum


I started doing a drawing then realized I have way more reserch to do, I dont know enough about foam trailers to make a drawing yet. Please help! :p
This is just of the lower half. Do I need a verticle in the middle of the 10ft length? The middle horizontal framing at the 2ft hight is to attach the dividers inside to.
Going to do some more reading now.

[loaderman]

With a festiva as a tow vehichle you need really light, and really aerodynamic, and as low as possible. For 4 people and all your gear that is a tall order.

Ok for aerodynamics keep it as low as possible, rounded front tapered to the back. This is considered the optimum shape.


The narrower the better perhaps you could go 4'6" wide? a double bed. Narrow and long is better then wide and shorter.
Also use torsion axles to save weight. and an aluminum alloy frame for the trailer, not straight aluminum as it is considered to soft from my reading. There are also other special considerations in using aluminum so talk to a reputable welder/ trailer maker.
A possibility is a pico light frame design http://www.tnttt.com/viewtopic.php?t=34755



Look at motorcycle camping trailers. they have small weight. To stay in your weight restrictions you will need some sort of tent type trailer. Maybe even a trailer that you put a tent on! So you store your stuff in trailer when traveling, then put it in the car while you sleep in the trailer. Yes I know it is a little work but with your weight constraints....

Here is a roof top design that is good you could adapt the principles for your size.

[loaderman]

Use as little wood as possible as it is really heavy. foam and canvas is much lighter. GPW will hopefully tell you the numbers.

Do not haul water it is 10lbs per gallon. so only get it as you need it. say 1 day supply not 3 days and cuts the weight by 2/3rds!!!!

Your trailer is way to heavy to start, like I said above aluminum and pico light are what I would look at.

[lthomas987]

For your door thoughts and some design ideas look at the Army Goose build. Foam is really tough. Look at the fate of the first Penguino! You need very little wood framing. Mostly just around doors and windows.


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[dancam]

With a festiva as a tow vehichle you need really light, and really aerodynamic, and as low as possible. For 4 people and all your gear that is a tall order.

Ok for aerodynamics keep it as low as possible, rounded front tapered to the back. This is considered the optimum shape.


The narrower the better perhaps you could go 4'6" wide? a double bed. Narrow and long is better then wide and shorter.
Also use torsion axles to save weight. and an aluminum alloy frame for the trailer, not straight aluminum as it is considered to soft from my reading. There are also other special considerations in using aluminum so talk to a reputable welder/ trailer maker.
A possibility is a pico light frame design http://www.tnttt.com/viewtopic.php?t=34755



Look at motorcycle camping trailers. they have small weight. To stay in your weight restrictions you will need some sort of tent type trailer. Maybe even a trailer that you put a tent on! So you store your stuff in trailer when traveling, then put it in the car while you sleep in the trailer. Yes I know it is a little work but with your weight constraints....

Here is a roof top design that is good you could adapt the principles for your size.

Hey, Thanks for the Ideas, I don't think 4ft 6 would work well with my floor plan as far as fitting stuff in there. Wouldn't be enough room to walk through with the way I am imagining it and making the storage area narrower would mean stuff not fitting. It would be better for aerodynamics though for sure. I saw some trailers with torsion axles but I was not able to locate brakes for the torsion axles I saw. Braked axles that just bolt straight to the trailer I bought are easy to find.

As far as trailer materials and designs I saw a galvanized steel one that looked alright but everything was rivited and it was pricy and had a torsion axle. Aluminum trailers I found were double the money of steel ones. I think $2700 was the cheapest 5x10 I found which is crazy. Also looking at some of the trailers used and made on this site and others in the usa blows me away. A trailer here has to be inspected and have a vin to get registered to pull and a lot of stuff I am seeing wouldn't pass. I don't think 310 pounds is too bad for a sturdy trailer base. I would think a boat trailer or homemade thing would want to twist a lot while driving and living in it and place a lot of stress on your walls and foam frame wouldn't it?

I looked at the tent trailer stuff and did consider it. However a large (for4) rooftop tent is like $2000 and a homemade system would take a lot of time. This isn't like regular camping where you go somewhere, set up then leave it for a few days. We will be setting everything up and taking everything down every day for 90 days in all kids of weather. Hauling everything back and forth while its pouring or setting up a tent would take a lot of fun out of it.
As far as water we will be travelling through some fairly remote areas. When we are in highly populated areas we can refill the water every day or 2 days and carry less, but I want to have storage capacity for 3 days if we feel we need it.

Shouldn't be too hard to stay within my weight constraints with foam. Even with my wood frame detailed above it was only 170 pounds over at 1870 pounds. If I Take off the bikes and bike rack its 1720 pounds (-150). Take off the bikes, the boat, its motor and the spare battery and its 1630 pounds. So it was achievable even with the plywood build.
However some weights change. Water is heavy, We plan to take 3 days worth of water which is 87 litres or 190 pounds. As we use it up that gets less. A full 20L gerry can is 35 pounds but in more populated areas I don't need it, in moderately populated areas it could be half full. Propane bottle is 38 pounds full, gets lighter as we use it. I planned on 100 pounds of food, That may be high, but I prefer to guess high and have the result low rather than guess low and end up stuck later. So thats 360 pounds of stuff that varies regularly. Once were low on water, empty gerry can, half full propane bottle were down to 45 pounds instead of 360.

Then technically this trailer is lighter being aerodynamic than a u-haul of less weight. Wind blowing on something actually increases its mass quite a bit. Think of holding a sheet of plywood in a strong wind. Your weight doesn't change but the force of the wind on the plywood becomes a large mass that given enough wind you cannot support. Say you put a 10ftx10ft garden shed on a trailer and pull it with a truck. The trailer and shed only weigh 5000 pounds lets say but the force of the wind on that shed could perhaps triple the mass you are pulling and the force on the ball from the trailer. Whereas the same trailer with a bunch of flat steel on it would still be 5000 pounds rather than 15,000 like with the shed. I am just guessing with these numbers by the way, But when you think about it it makes sense. When I pulled the u-haul thats 5th gear floored or 4th gear half throttle to pull a 900 pound trailer that sticks 2ft above the cars roofline. The same 900 pounds in a trailer that fits nicely behind the car is no different at cruising speed than driving with no trailer. So making a trailer that is aerodynamic and fits well behind the car reduces the pulling force on the hitch and how hard the car has to work considerably. For braking when you have trailer brakes they take a lot of the force off the hitch while stopping.

[dancam]

For your door thoughts and some design ideas look at the Army Goose build. Foam is really tough. Look at the fate of the first Penguino! You need very little wood framing. Mostly just around doors and windows.


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Thanks for those! I like that army goose one, I didn't realize that velcro wouldn't leak. I like the way he attached the floor to the wall too. That penguino held up well, I am surprised and impressed! Did a lot of reading today, Its a lot to take in and a lot of different options :/

[loaderman]

I looked up recommended towing capacity for the festiva, it is about 500lbs! by going over 1500lbs you are risking blowing the transmission.
Driving 90km/h (about 55mph) will help a lot.

A 5'" wide trailer (outside measurements) , abuot 7' long, and about 16"' high with a flip lid (another 6" to the height) for a total of 24" max height. The lid flips open to the side, that pulls the tent top up as you open it. So very quick set up. The lid becomes the parents bed. the bed also is the Bench for sitting at a couple of tV trays that is why the 16" height to the main trailer body.

A 16" shelf across the front, gives you lots of storage. 16" by 4'6" under the shelf then stuff on the shelf when parked. So 9' of storage space
2 mats about 27" by 4'6" for the kids bed side by side on the floor or you could put one on the floor crosswise and 1 above with legs under a "shelf" bed for them. This would give you more open floor space at the back inside the door. These can be rolled up or put on the parents bed so not being walked on.

Take a look at the pico light frame link I gave above. Use your axle if you must and then that triangular frame.
do a sandwich floor construction. painted canvas,1/4" plywood, 2" styrofoam, 1/4" plywood, light and strong.

An awning for the entry door would be nice, cause in 3 months you will get rain, shade is also nice.

This could be well under 1000lbs and probably more like 500lbs.

I could do up a 3d drawing if you are interested?

If you do a trip through canada and alaska I would love to meet you. I am Canadian and have lived in 5 provinces, my wife has lived in 6! We are near Dawson Creek B.C. which is the start of the Alaska Highway.

[loaderman]

Aerodynamics doesnot affect braking and those little brakes are going to be working hard in the mountains! LOL

[GPW]

Dan, Like that Trailer , and we always wanted to see a cabin built on one of those ...

[KCStudly]

I would think a boat trailer or homemade thing would want to twist a lot while driving and living in it and place a lot of stress on your walls and foam frame wouldn't it?

Absolutely not! (With caveats.) A relatively flat trailer frame does not stiffen the cabin a whole lot. Think of it this way instead, the 3-dimensional structure of a light but sturdy cabin stiffens the trailer! The strength comes from the sum of all of the light weight parts, not from any single part or element of the build. Think Bird Cage Maserati (a race car built with no major frame work, just a bunch of little tubes), not Sherman Tank (a heavily armored vehicle).

Over building (and over accessorizing) is a slippery slope; the heavier you go and the more features you add, the stronger the structure needs to be in order to support itself. With regard to storage for "stuff", I'm reminded of George Carlin's bit.

The caveats are that you need to build with nice tight sound joints, and in a purposeful manner. So do dry fit tests of your joints before you glue and make corrections to fit as needed; clamp, biscuit join, screw or otherwise reinforce your glue ups; don't use rickety hardware store brackets and rough cut lumber w/o any glue; use your bulkheads and cabinet frames as integral structure, or add stiffening ribs (ala GPW's foam arch concept); and secure the cabin through the floor around the perimeter using several modest sized bolts or TEK screws rather than just a few large ones.

The strength comes from the depth of section (mostly wall height and bulkhead width, but also separation of the inner and outer skins on any given member) and the strength of the outer fibers (skins). The advantage of foam over wood is that it is so much lighter, yet relatively non-compressible over large areas; it holds the stronger outer fibers, the canvas, thin ply, or FG skins, where they need to be to do the most good. Think of an 'I'-beam: the flanges do the work while the center web keeps the flanges separated. The deeper the section (taller beam) the stiffer the beam. Now look at the typical cabin box. The walls are very tall compared to the height of the trailer frame tubing or channel. Despite being made from weaker materials, the depth of section is so much larger that the outer fibers have more leverage, in effect, and end up being so very much stiffer. That's also why a 1-1/2 inch thick canvas coated piece of light weight foam is as strong (dare I say stronger) in bending than a heavy piece of 3/4 inch plywood.

Special consideration may have to be given to a Goose style build that has a relatively large opening, but that, too, is doable.

You will be amazed at how rigid a lightly built structure becomes when it all comes together. The trailer is not the foundation to a house, it is merely a bracket that connects the tongue and axle to the cabin.

How many times have you read a builder comment that as soon as they put the roof skins on their cabin stiffened up remarkably? My trailer, made out of 2x2 steel tube, is still out in the yard. If I sit on the back xmbr it flexes about the suspension points just a little bit before the jack lifts off the ground. With the roof on my cabin I can nudge any corner of the floor or walls, or start to lift it and the whole thing moves as one; no flex. None. Solid as a rock, but light enough for me to push around. (Okay, I admit that my build is not going to set any records for being the lightest foamie out there, but the point is the benefits of unit construction work.) So what do you think is going to happen when I bolt it to the trailer frame? That's right, the trailer will be held rigidly by the cabin. (This is also why it is so important to have a sturdy tongue and integrated connection to the trailer frame proper; because the point of flexure now becomes the joint between tongue and front xmbr.)

Trailer frame: Flex.
Cabin Floor: Flex.
Walls up: Flex.
Bulkhead in: Okay, now we are getting somewhere.
Cabinet face frames in: That made a difference, too.
Front wall on: Hey this thing is starting to get pretty rigid.
Roof on: Granite baby! This thing is solid as a rock and isn't going anywhere.

[GPW]

The beauty of foam is , if you want something stronger , just add more Foam , Like the old saying “ twice as thick is Eight times as strong! “ ... and foam is the lightest component so feel free to add as much as you want ... (within reason ... )

[dancam]

I looked up recommended towing capacity for the festiva, it is about 500lbs! by going over 1500lbs you are risking blowing the transmission.
Driving 90km/h (about 55mph) will help a lot.

A 5'" wide trailer (outside measurements) , abuot 7' long, and about 16"' high with a flip lid (another 6" to the height) for a total of 24" max height. The lid flips open to the side, that pulls the tent top up as you open it. So very quick set up. The lid becomes the parents bed. the bed also is the Bench for sitting at a couple of tV trays that is why the 16" height to the main trailer body.

A 16" shelf across the front, gives you lots of storage. 16" by 4'6" under the shelf then stuff on the shelf when parked. So 9' of storage space
2 mats about 27" by 4'6" for the kids bed side by side on the floor or you could put one on the floor crosswise and 1 above with legs under a "shelf" bed for them. This would give you more open floor space at the back inside the door. These can be rolled up or put on the parents bed so not being walked on.

Take a look at the pico light frame link I gave above. Use your axle if you must and then that triangular frame.
do a sandwich floor construction. painted canvas,1/4" plywood, 2" styrofoam, 1/4" plywood, light and strong.

An awning for the entry door would be nice, cause in 3 months you will get rain, shade is also nice.

This could be well under 1000lbs and probably more like 500lbs.

I could do up a 3d drawing if you are interested?

If you do a trip through canada and alaska I would love to meet you. I am Canadian and have lived in 5 provinces, my wife has lived in 6! We are near Dawson Creek B.C. which is the start of the Alaska Highway.

Aerodynamics doesnot affect braking and those little brakes are going to be working hard in the mountains! LOL

Fair enough, that's probably what it is in this country. I could start a thread about the car in the towing section later. Starting on that in a thread about trailers always seems to derail things... But the car will be able to tow whatever trailer I make safely for the 30,000km. I have a plan for getting the car ready for a trailer under 1700 pounds.
I looked into those tent trailer types, it was originally what I wanted to do, but we decided against them for a few reasons. I have never seen one in person so here is why we decided against it and please tell me if I am wrong about anything on them.
Pros:
-Smaller
-lighter and easier to tow
-much Larger sleeping area!

Cons:
-The tents that are meant for it are very expensive. what I saw was upwards of $2000
-I could buy my own tent and fasten the tent peg hooks to the plywood. It would have to have to be all internally supported with no ropes for the fly or exterior poles. Less expensive then the 2k ones, but still not a cheap tent.
-The tent would be folded up wet almost every day. Either from the dew or if there was rain. I don't see it drying out very well while driving if it is sealed well enough to prevent it from being in a lake if it rains while your driving. The tent would eventually stink, get mildewy/moldy and always be damp
-I think it will rain a lot, were setting up and taking down every day and we will get wet setting it up, once the tent is set up everything like air mattresses, air pump, sheets, pillows, food, lights, books... has to be hauled into the tent from the trailer and then put back in the morning. That not only takes extra time, but when its raining your stuff and you get soaked. One thing about me- I absolutely hate getting wet unless its a shower in a house... :p swimming pools, water fights, rain is all a big no for me, lol.

Am I wrong on any of that?
So on the trailer I will build I want to make some awning so that if it is raining a little sideways we can still cook.

I would love to visit people! We do not have our route confirmed yet. Our rough plan is to leave the Edmonton area and head west out to the queen charlottes, then up to Alaska on hy 37 from Kitwanga. On our way back at the very end we were going to come up from the Vancouver island area up hy 97 to prince george. Then if we were running behind we could head on hy16 straight home, but if we still have time as planned we were going to head up 97 which goes straight into dawson creek! I asked on other forums if people want to meet us and I probably will here before we get our route planned out but I am pretty new here yet I am making a list of people to try and visit and I will add your name to it and get back to you once we are farther along that part of the planning.

Aerodynamics doesn't affect braking, but trailer brakes sure do! And this car stops a 900 pound trailer surprisingly fast.

With the 3d drawing-that does sound interesting! Just let me figure out a bit more what my plans are and then I will send you a pm about it ok? Thanks

[dancam]

I would think a boat trailer or homemade thing would want to twist a lot while driving and living in it and place a lot of stress on your walls and foam frame wouldn't it?

Absolutely not! (With caveats.) A relatively flat trailer frame does not stiffen the cabin a whole lot. Think of it this way instead, the 3-dimensional structure of a light but sturdy cabin stiffens the trailer! The strength comes from the sum of all of the light weight parts, not from any single part or element of the build. Think Bird Cage Maserati (a race car built with no major frame work, just a bunch of little tubes), not Sherman Tank (a heavily armored vehicle).

Over building (and over accessorizing) is a slippery slope; the heavier you go and the more features you add, the stronger the structure needs to be in order to support itself. With regard to storage for "stuff", I'm reminded of George Carlin's bit.

The caveats are that you need to build with nice tight sound joints, and in a purposeful manner. So do dry fit tests of your joints before you glue and make corrections to fit as needed; clamp, biscuit join, screw or otherwise reinforce your glue ups; don't use rickety hardware store brackets and rough cut lumber w/o any glue; use your bulkheads and cabinet frames as integral structure, or add stiffening ribs (ala GPW's foam arch concept); and secure the cabin through the floor around the perimeter using several modest sized bolts or TEK screws rather than just a few large ones.

The strength comes from the depth of section (mostly wall height and bulkhead width, but also separation of the inner and outer skins on any given member) and the strength of the outer fibers (skins). The advantage of foam over wood is that it is so much lighter, yet relatively non-compressible over large areas; it holds the stronger outer fibers, the canvas, thin ply, or FG skins, where they need to be to do the most good. Think of an 'I'-beam: the flanges do the work while the center web keeps the flanges separated. The deeper the section (taller beam) the stiffer the beam. Now look at the typical cabin box. The walls are very tall compared to the height of the trailer frame tubing or channel. Despite being made from weaker materials, the depth of section is so much larger that the outer fibers have more leverage, in effect, and end up being so very much stiffer. That's also why a 1-1/2 inch thick canvas coated piece of light weight foam is as strong (dare I say stronger) in bending than a heavy piece of 3/4 inch plywood.

Special consideration may have to be given to a Goose style build that has a relatively large opening, but that, too, is doable.

You will be amazed at how rigid a lightly built structure becomes when it all comes together. The trailer is not the foundation to a house, it is merely a bracket that connects the tongue and axle to the cabin.

How many times have you read a builder comment that as soon as they put the roof skins on their cabin stiffened up remarkably? My trailer, made out of 2x2 steel tube, is still out in the yard. If I sit on the back xmbr it flexes about the suspension points just a little bit before the jack lifts off the ground. With the roof on my cabin I can nudge any corner of the floor or walls, or start to lift it and the whole thing moves as one; no flex. None. Solid as a rock, but light enough for me to push around. (Okay, I admit that my build is not going to set any records for being the lightest foamie out there, but the point is the benefits of unit construction work.) So what do you think is going to happen when I bolt it to the trailer frame? That's right, the trailer will be held rigidly by the cabin. (This is also why it is so important to have a sturdy tongue and integrated connection to the trailer frame proper; because the point of flexure now becomes the joint between tongue and front xmbr.)

Trailer frame: Flex.
Cabin Floor: Flex.
Walls up: Flex.
Bulkhead in: Okay, now we are getting somewhere.
Cabinet face frames in: That made a difference, too.
Front wall on: Hey this thing is starting to get pretty rigid.
Roof on: Granite baby! This thing is solid as a rock and isn't going anywhere.

Hey, Thanks for explaining that so well, and I apologize for not making myself more clear. I was not referring to solid, square builds, but mine in particular. I saw the penguina crash photos and I work with fibreglass-covered foam all the time when we make custom shower floors. Its very tough- you can drive a truck over it. There is even a company building houses and commercial buildings with foam and steel, no concrete. They are based about an hour from here.
I was referring to what I am considering building where it is not a solid box. The bottom part will have sides attached to the floor and have the interior dividers to stiffen them, but no roof. The top part has walls attached to a roof, but no floor. When closed I was thinking of 8 latching points but that does not provide strength. All the weight of our stuff will be along the perimeter. We only walk in the center, but when were sleeping weight is put all over. So I understand a complete box is very strong, But I would be concerned about the stress placed on the corners and walls with a minimal frame and what 30,000km of fatigue from rough roads would do. I have a feeling a lot of the roads we take will be gravel or older, I like to travel off the beaten bath And utility trailers move a ton when you hit large bumps or take a speedbump on an angle.

So am I wrong about any of that? Is it a cause for concern with a minimal frame or not? I was planning the build with 1.5in foam and 2x2 wood. I saw in the army goose build some interesting Ideas that I think I can use to have less wood framing.

With the steel frame I have there are a decent amount of crossbeams between the perimeter widthwise. I was thinking of using 1/2in plywood, doing canvass glue and paint on each side, laminating 1/16 plastic or something to the bottom side then gluing or double-sided taping it to everywhere it touches the frame. (They make good double sided tape now, its used to hold trailers together commercially). Then running a bunch of bolts through as well. That way the entire frame becomes part of the structure and should reduce flex or at least spread out the stress instead of concentrating it near where the bolt and pressure points are. Then making foam stiffeners underneath front to back like in the goldbrand trailer.

As for the stuff we bring, it has a lot to do with going with the kids... Our inflatable boat isn't small but I would really hate to not be able to go boating, I love exploring lakes. Then with food and water for 3 days- shopping every single day isn't possible and wastes so much time... :p
I am going to talk to much more experienced campers about packing lighter before we go though.

anyhow, I did not have time for much research today, I got home late. So tomorrow after I mow the lawn, run off some fat and change my water filter I will look at how to seal the seam in the style of trailer I am thinking of building. (Any suggestions?) Read a few more threads, see if I find any trailer designs I like more or are simply more feasible then come up with a basic sketch and a few plans and hopefully post it here and see what you guys think.

[KCStudly]

The theories all still apply. If you build your lower section to cabinet/counter top height, instead of just placing storage units, you can integrate them into the side walls. The walls become the beams and the cabinets become the gussets. Still build them light, but they will be strong if you integrate them into the structure.

Changing the water filter, that's something I need to do, too.

[loaderman]

Think of it more like building a really light cabinet then a house with studs and framing! LOL

You are thinking right that aerodynamics is a key thing in towing. wind drag is a big issue.
Rounded front and tapered to the back, that way the wind you displace actually pushes you forward as it goes over the taper to the back. (I Love physics )

AS stated before the whole unit is much stronger then the parts. Rounded roof with the teardrop shape makes it strong.
There is a thread where A guy used bent up metal flashing instead of wood to attach his door and window and such. It worked well and was much lighter then wood.

Driving 90km or 55mph is easier on things too.

Man I am excited for you a 3 month trip through canada and Alaska would be great.