Small caravan box by Tom

[clanga]

Great ideas and skills Tom.
How do you get the camper off the trailer now?

[pchast]

Great!

[dales133]

Realy like this trailer Tom.
You said your disappointed it's not "a real teardrop shape" but I love the shape.
It's got a 1970s nostalgic retro coolness about it.
Pleased to see you didn't loose heart with the misshap you had because it's way to cool to give up on

[ipy]

Hello my friends. Today I saw my caravan box in a harsh sun and I realized that there is no point in developing this project anymore. Both PVC and policarbonate melt and deform. Even worse, polycarbonate panels tear off MFP construction because they deform so bad that their dimensions inrease and create waves and tops of waves come off construction even though I used a very strong glue. I could not see similar effect on PVC panels but I can expect it would appear.

So I say bye bye to this box and start building another one. Similar in size and shape, but:
- made from plywood installed on thin pieces of wood;
- between internal and external shells of a plywood there will be a polystyrene foam;
- I will make only the part that goes above trailer boards;
- I will redesign the rigth wall so it would have a long table to be open down, full height towards rear, looking from a kitchen hatch;

If you could tell me please about your experiences with a plywood- does it change its dimensions as a result of a temperature change? Here in Poland we have temperatures down from -35 degrees Celsius (-31 Farhrenheit) up to 40 Celsius (104 Fahrenheit).

What kind of a plywood should I choose (coniferous/ deciduous wood)?

[noseoil]

Tom, sorry this one didn't work for you, but you learned a lot about materials & their use in builds! I have to say congratulations on a job well done & a great design concept, even if it didn't go as you wanted it. I think you are on the right track with the plywood.

I used 3/4" plywood (about 19mm) for my frame, the skeleton, and 3mm for the inside & outside skins on my build. It isn't finished yet, but this seems to be a good way to build and works for everyone who uses it, so I figured I was safe with this method. Here in Tucson I have similar concerns about the temperature. While in the winter it seldom gets to -6c, it does go up to 45c, which means the surface of something in the sun is much hotter, about a 50 degreec change during the year. Inside a car it can get up to 66c on a hot day in the summer. I'm not worried about the wood & expansion, as long as the glue is good there will be no problems with this type of build.

I know weight is a concern to you on your build, so you might consider using 3mm birch plywood on the inside, & just a thin aluminum skin on the outside. If the aluminum is glued in place with a marine adhesive on the framework, it will stay forever, look good & not have any problems with heat or moisture. In the states here we have access to 0.025" aluminum material (about 0.5mm) which would be strong enough & light enough for a small trailer. See if you can find something like that to use.

Best of luck & I really like your design concept!

[ipy]

Here in my city I can easily buy in a supermarket a 4mm plywood from deciduous wood (hardwood). Got a piece inside cabin on a side wall, around window and the plywood does not seem to be too heavy.

In all corners of a trailer there are slots about 2,5 x 2,5 cm of internal size, whole height of boards. I plan to put a wood inside and this wood will be a corner of a skeleton. Rest of skeleton will be made from the same type of wood.

At the picture: gray part with black border is a trailer corner with internal slot, orange is a wood, green is plywood outside and inside and red is a screw going through a hole in board (seen on a photo).

As I plan, there will be only upper part of the trailer. I will use trailer boards and floor at the moment. On autumn I can make internal floor with an insulation but now I do not want to waste my time on this.

I think I will paint external shell with an acrylic paint, as I know it is a good and reliable protection against moisture.

Places where walls touch trailer boards will be covered with aluminium profiles or something similar.

Please tell me what do you think about my plan and what are the weak points. Thank you.

[Sheddie]

Hi Tom, sad news. One good thing to say about it, is at least you had not started on the interior finishing. I used mostly the same construction method as Tim, with 19mm exterior grade construction ply, an inner lining of 4mm hardwood ply, but on the outside I used ACL (aluminium composite laminate). It is a plastic composite core with a thin skin of aluminum each side, and is mostly ready painted. It is used a lot by sign writers. The only changes I would make on another build, would be to cut more out of the 19mm sheets.
Looking at your plan. You should look at taking the outer skin down past the top of the trailer sides, to make sure that water can't seep through the gap. Also instead of using screws to hold the camper body to the trailer, have a look at over centre latches.
Good luck with your build.

[dales133]

Is there any reason you can't just re skin it in sam ply and cover it in painted canvas?
Be a shame to have to start again but at least if you do have to you've learned alot and will make you a far better builder

[ipy]

I had to start like new because while designing first version of a box I planned a heavy core and lightweight shells on it. If I removed PVC and polycarbonate panels and replaced them with a plywood then weight would increase too much. Besides that, I found it difficult to remove layers of PVC without cutting through the protective layer of MFP and it would take me very long. Creating a plywood shells on a skeleton made from wood is just a while. I will reuse impregnated wood from my first project and the rest of MFP that left as well.

I redesigned kitchen unit a bit because first time i bought water sink after I cut w hole in a wall of a box and then it turned out that it does not fit perfectly.

Now I have finished both walls. Just external skin and wooden skeleton. Slightly redesigned shape of the roof and the whole construction is a bit lower. Thereare holes for a lamp and vent on both sides of the kitchen unit.

[dales133]

I can already see how much you've learned from the first build in these photos.
Very very neat and tidy workmanship.
I'll be following build 2 just as closely.
Keep up the good work tom

[Sheddie]

Well Tom, you sure don't stuff around. Good on you for not loosing heart and getting straight back in to it. What you have done so far looks really good From my point of view, I am much more comfortable with the materials you are using this time. The MPF you were using for the main structure looks very much like what we know here in New Zealand as chip board. Basically small wood chips compressed together with some sort of resin. Problem is that although it looks good and solid (and used in the right application it is good and solid), but if any water gets to it, it swells up like a sponge and starts to disintegrate. Also it is very heavy compared to ply.
Good luck with version two
PS, Just as well you have the kitten to put all those screws in.

[noseoil]

Tom, I think this one will be very good! I like the material & your use of light weight techniques. Keep up the good work!

Oh, and I like the cat also. Unfortunately, our cats don't help much on my build, but they are very good at supervising the work while I do it.

[ipy]

I am very glad that there is such a website as TNTTT and that I could learn a lot about building lightweight yet strong constructions. It is great that other people share their experiences and that they are very helpful and supporting. Thank you friends.

Today I made external part of that small front wall on which there will be vents installed. Also applied insulation and internal plywood on both sides of the front part of the caravan, where my daughter will sleep.

I decided that between child bedroom and a 'living room', full length of a kitchen unit, there will be a storage space on both walls. Therefore I divided internal wall finishing into 3 pieces on each wall: child room, storage/ kitchen unit, living room.

Unfortunately, supermarket ran out of plywood and the crew managed only to cut small pieces for a child room. So I used them and wait for next delivery, which is expected in a couple of days.

[ipy]

While waiting for a plywood delivery to my supermarket I dismantled old version of the capsule. It was not too easy as I had to cut through walls, being unable to simply unscrew wood because of presence of PVC and polycarbonate layers.

Here is a picture of a cross section of top right edge. That was a solid thing but I must say new version is much lighter.

I placed walls of a new version on their working positions. Hope to start building today.

Could you please have a look at this foil:

http://www.easygrow.co.nz/reflective-fi ... -122m.html

Would it be good to cover side walls with?

[Breytie]

You are not slowing down for anything!
Congrats!
May this build go as quick, as beautiful and much more durable!
I am watching with great interest.