Advice Please on Canvass Sides

Tucson T4R

Expedition Leader
My KK trailer has the window flap design and it does work very well by allowing you have the windows open while it's raining. The flaps have corner grommets so you can stake them out at and angle to protect the window from the rain but still have great ventilation.

BTW, my window flaps are zippered on the sides and just Velcro at the bottom edge when closed if you want to consider that option.
 

JMPC

Observer
My KK trailer has the window flap design and it does work very well by allowing you have the windows open while it's raining. The flaps have corner grommets so you can stake them out at and angle to protect the window from the rain but still have great ventilation.

BTW, my window flaps are zippered on the sides and just Velcro at the bottom edge when closed if you want to consider that option.

Thanks Tuscan

Again, I hadn't thought about having windows open while raining, but obvious of course!


Have you any pictures?

All the best
JMPC
 

Lynn

Expedition Leader
Thanks for your reply, ultimatly, given a choice, which would you prefer, the benefits of canvass (lighter weight and able to create a much more open environment when camping) or hard walls?

Since you asked, I, personally, would rather have a hard-sided walls (better insulation, security) with largish windows set in really large opening panels.

Like what Bimobile does,

G_3.jpg


or what Rob Gray did with Wot I.
15721.jpg


I would strive to use the lightest construction possible, but it would certainly weigh more than a canvas approach.

I want to be comfortable in either very hot or very cold environments, and I don't believe it would be very difficult to get sufficient insulation with soft sides.
 

Tucson T4R

Expedition Leader
Thanks Tuscan

Again, I hadn't thought about having windows open while raining, but obvious of course!


Have you any pictures?

All the best
JMPC

This one shows the large end screened panel:

07GilaCamp19.jpg
[/IMG]

The canvas windows roll up when you just want the screen in good weather:

DSC02422.jpg
[/IMG]

Larger view with all the canvas sides on:

RichmondBasin07086.jpg
[/IMG]

Side window rolled up:

RichmondBasin07047-1.jpg
[/IMG]

Hope that helps.
 

JMPC

Observer
This one shows the large end screened panel:


The canvas windows roll up when you just want the screen in good weather:



Larger view with all the canvas sides on:



Side window rolled up:



Hope that helps.

Thanks Brad

AAAHHHH I´ve finally twigged - KK = Kimberly Kamper!

Very nice set up I see. Is that a ZODI I spy? You guys have all gear, Very nice!

Thanks for the pics, certainly give some good ideas

All the best
JMPC
 

JMPC

Observer
Since you asked, I, personally, would rather have a hard-sided walls (better insulation, security) with largish windows set in really large opening panels.

Like what Bimobile does,

G_3.jpg


or what Rob Gray did with Wot I.
15721.jpg


I would strive to use the lightest construction possible, but it would certainly weigh more than a canvas approach.

I want to be comfortable in either very hot or very cold environments, and I don't believe it would be very difficult to get sufficient insulation with soft sides.

Thanks again Lynn

great pics. I have seen the WOT 1 before, fantastic! (What On Earth Is That?, I think is the acranym, correct me if I´m wrong?)

I do agree with you, ultimatly one can´t expect insualtion to work as well with soft sides. And of course security, or perceived security is certainly not as good.

Thanks for the opinion

All the best
JMPC
 
Last edited:

Lynn

Expedition Leader
Sorry, but I just can't seem to stay away from this one. Possibly because I'm airing and evaluating my own thoughts on the idea :)

Anyway, I was thinking, how much weight are you going to save with double soft walls, insulation, and chicken wire versus a fiberglas/styrofoam sandwich w hard walls? I'm guessing not much. The heaviest part of either approach is the framing, and that might actually have to be heavier with canvas. Especially if you could build the sandwich walls as SIP (Structural Insulated Panels) and only reinforce where necessary.

That's my theory, and what I'm planning, so I'm hoping someone who has done the engineering analysis will chime in here and save me the trouble. :)
 

Lynn

Expedition Leader
Oh, and if you are building this as a trailer, I think you should pull it with a Velorex:

DSCF2463-01.jpg


velorex-2.gif
 

dsw4x4

Adventurer
Here is what my research of pop up slide in found. Here in Colorado the manufacturers use Aqualon or and equivilant. Rockwalon (rockford supply own name) also know as a spa material (hottub covers) sandwiched with 1/8 or 1/4 foam (think a big roll of packing foam is what they use) in between two layers, most between two layers of aqualon. Some use aqualon on the outside and a breathable fabric on the inside. I am guessing to eliminate encapsulating moister in with the foam. Aqualon or an equivilant will not breath no matter what, the plus is it will not leak no matter what! I use either single wall aqualon on our vans or double wall if the owner wants it built for four seasons. Currently my van (1st prototype) uses a pack cloth "breathable/ waterproof" material, yes it sweats and it leaks if you are constantly touching the inside on a rainy day. Sunbrella type fabrics will still leak and sweat (climb under a boat on a rainy day) after time. The big draw back is they take a long time to dry out. So if it rains on vacation chances are your fabric will be wet the whole time until you get a breeze sunny warm day. These fabrics also seem to not have very good abrasion resistance. If you pinch it closing your top and drive down a wash board road that area is now going to leak.
My advice would be use a water proof non breathable material for any surface that can hold water. If you really want breathable and not by opening a window than use breathable fabric for the walls and if you can design the wall so that it slightly tilts out ward and give it a overhang if possible. This keeps the rain off of it and allows it to drain outwards instead of absorbing it into the fabric.
Don't take this info to the bank! I just know how hard it is to find out any info on this stuff and how many choices there are out there. The only people that seem to know anything are the sales man and of course their material will rock your world stand up to a hurricane keep you dry and last 40 years!!! Riiiiight.
Good luck and hope this helps.
Derek
 

JMPC

Observer
Sorry, but I just can't seem to stay away from this one. Possibly because I'm airing and evaluating my own thoughts on the idea :)

Anyway, I was thinking, how much weight are you going to save with double soft walls, insulation, and chicken wire versus a fiberglas/styrofoam sandwich w hard walls? I'm guessing not much. The heaviest part of either approach is the framing, and that might actually have to be heavier with canvas. Especially if you could build the sandwich walls as SIP (Structural Insulated Panels) and only reinforce where necessary.

That's my theory, and what I'm planning, so I'm hoping someone who has done the engineering analysis will chime in here and save me the trouble. :)

Weight saving I guess will work out at about 200kg, after everything is taken into consideration, angle to knit walls and roof together, windows, etc.

For me, one of the main reasons for going for a canvass is ease of manufacture, just drop it over the top`and cost. It also allows me to have as many windows as I like, and of any size.

Complete 'off the shelf' window units with integral blinds and flyscreens run into appox. £500 or $700 per window, and that's not even getting the window size i want. So here, for what I wish to acheive, I´m looking at a bill of a £2000 or $3000 just for these alone. I have made windows myself before, and they worked out OK, but these are perhaps the most difficult component to make onself as margin for error is small.

Ridged hard walls that come perfabricated with a sandwich contruction, GRP exterior and interior with a styromoam middle, are certainly a good option, and you´re quite right they do need less framing, as they self support. It may still be the option I go for, but the cost here is about £80 or $130 per sqaure metre. So this quickly gets pricy too.

They do have other benefits too, however, that are worth considering, one of the main ones being that colour range is very good, so no need for any kind of spray painting. So that's another point in their favour.

The deliberation contunues! Thanks again for your thoughts, much appreciated.

All the best
JMPC
 

JMPC

Observer
Oh, and if you are building this as a trailer, I think you should pull it with a Velorex:

DSCF2463-01.jpg


velorex-2.gif

Lynn

This is my tow vehicle! How did you know? Although mine is in poor condition and needs much work, unlike the fine examples shown here:)

All the best
JMPC
 
Last edited:

JMPC

Observer
Here is what my research of pop up slide in found. Here in Colorado the manufacturers use Aqualon or and equivilant. Rockwalon (rockford supply own name) also know as a spa material (hottub covers) sandwiched with 1/8 or 1/4 foam (think a big roll of packing foam is what they use) in between two layers, most between two layers of aqualon. Some use aqualon on the outside and a breathable fabric on the inside. I am guessing to eliminate encapsulating moister in with the foam. Aqualon or an equivilant will not breath no matter what, the plus is it will not leak no matter what! I use either single wall aqualon on our vans or double wall if the owner wants it built for four seasons. Currently my van (1st prototype) uses a pack cloth "breathable/ waterproof" material, yes it sweats and it leaks if you are constantly touching the inside on a rainy day. Sunbrella type fabrics will still leak and sweat (climb under a boat on a rainy day) after time. The big draw back is they take a long time to dry out. So if it rains on vacation chances are your fabric will be wet the whole time until you get a breeze sunny warm day. These fabrics also seem to not have very good abrasion resistance. If you pinch it closing your top and drive down a wash board road that area is now going to leak.
My advice would be use a water proof non breathable material for any surface that can hold water. If you really want breathable and not by opening a window than use breathable fabric for the walls and if you can design the wall so that it slightly tilts out ward and give it a overhang if possible. This keeps the rain off of it and allows it to drain outwards instead of absorbing it into the fabric.
Don't take this info to the bank! I just know how hard it is to find out any info on this stuff and how many choices there are out there. The only people that seem to know anything are the sales man and of course their material will rock your world stand up to a hurricane keep you dry and last 40 years!!! Riiiiight.
Good luck and hope this helps.
Derek

Derek,

Valuable insight, clearly from experience, thanks. As they they say ' the devil's in the detail' and your points about breathability, abrasion resistance, fabric drying times, are very uselfull. The sort of things that one only finds out after the money and hard work is put in.

Thanks for the input,

All the best
JMPC
 

JMPC

Observer
I'm a bit confused...couple of questions -
these are fixed, non folding walls? Permanent fabric walls in effect?
what sort of windows are you building & how do you mount them in fabric?
the roof also might be fabric?

England...fabric walls, damp = interior mold I'd think. Even waterproof fabrics have enough texture to retain enough dirt, dust & crud to feed mold - and you can't clean them really well - certainly not as well as a hard surface. Mold for me would be a real deal killer...


That's a lot of weight savings for sure...but I wonder if you made hard walls only as strong as fabric walls what would they weigh? You don't have to jump from fabric to a strong rigid composite - there is a middle ground. Maybe even just uninsulated ply walls - given that you want lots of windows - unless they are $$$ double paned the heat will blow right through them (or the cold in the other direction...) so insulation in the walls won't help much...That approach might be cheaper, more comfortable, easier to build & certainly longer lasting. Good ply with epoxy coatings & paint is extremely weather durable. It would just need a good heater...Peter

Hi Peter,

I´ve was very interested in your recent build project and seeing the level of craftsmanship involved ( well ,well above my level) i take your opinion very seriously.

You suggest a good compromise, and of course in comparison to most other options ply is very inexpensive. And, since starting this thread, I have also managed to source re-fabricated RV windows for approx a 1/4 of the price of the standard ones available. So all that's working out well.

In answer to your questions, if I went for canvass walls and roof, the windows would also be of fabric, or clear pvc.

What you say about mould is relevant, and well thought through, becasue an offroad trailer will encounter much dirtier conditions than a boat, where the majoiry of this type of cavass is used.

Suggestions much appreceiated - looks like I am leaning away from canvass.

Al the best
JMPC
 

UK4X4

Expedition Leader
personally I would not go the fabric route for anything seeing road use, even a steel trailer after 1 gravel road shows grit blasting along the front edge, I think you'd wear through pretty dam quick using a fabric.

I will be recovering my RTT with some marine polycanvas- no there's no coating as such its in the weave and probably silicone on the fibers themselves, but was concidering a laminated PVC type roof for the top and all the sides in the breathable material.

The boat poly canvas is extremly tough for its thickness.

Lightweight - UK weather, I'd stick with 3mm ply with a fiberglass top coat and re-inforced joints and webs, foam the inside if required.

I think my next trailer will be a pop top fold out type design as the babe is now a child and the dog refuses to move out of the RTT

Now if you look at old aircraft they used fabric over wood frame and then varnished it.........

maybe a neat solution would be to use a modern fabric and a resin top coat, I bet you could built a beautiful curved and ridgid structure and very light weight.

mmmmm I like that idea
 

ntsqd

Heretic Car Camper
snip.....

Now if you look at old aircraft they used fabric over wood frame and then varnished it.........

maybe a neat solution would be to use a modern fabric and a resin top coat, I bet you could built a beautiful curved and ridgid structure and very light weight.

mmmmm I like that idea
Just exactly what I was about to suggest. Light frame, stretch the fabric over it tightly, apply resin of choice.
 

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