Perseverance

[tomhawk]

Hopefully someone more in the know can elaborate on the preshrink process, and offer some tips.

I would think a trip to the washing machine and dryer would suffice? A question might be whether a fabric softener would hurt subsequent glueing. I would expect it might reduce wrinkles. Maybe not enough to risk it.

While waiting for the caulk to set on the hatch foam, work could continue on the canvas wrapping of the cabin.
I used a reciprocating tool fitted with the knife edge to trim overhanging foam bits. This is a very desirable tool for this and for cutting foam in general. I wish I had discovered its many uses earlier in the build.

From the chaos, as the fabric edges were trimmed and glued, a camper-trailer began to emerge.

Some lumps and bumps could be minimized by smoothing out with a clothes iron. Once the canvas edges were all trimmed and glued, my wife painted the outside with exterior latex paint. This greatly improved the appearance! Many cosmetic embarrassments became nearly imperceptible. The 10 foot rule almost hides them all.


Tom

[GPW]

Tom , it looks great !!! The Foamie' idea was never about glass smooth and shiny , but Light, affordable and easily constructed ( and long lasting ).

[tomhawk]

I made some rear stabilizers from scrap items. This allowed me to once again use my welder. The adjustments in height are made by placing a metal rod through holes in a nested piece of PVC pipe attached to the trailer chassis in front of the rear lights.

Note the "drip edge" of the canvas wall extending slightly below the chassis on the left.


The outside PVC pipe segment is clamped to a bracket that attaches to the chassis. It is composed of a 4.5" piece of 1" angle with welded nuts and a screw to secure to the 1" angle onto the rear lights holder bracket of the chassis. Spot welding nuts makes a solid screw attachment point. I don't have a tap & dye set. Since they are small enough and ventilation was present, I did not worry about the galvanized nuts emitting toxic zinc vapors.


With the tongue resting slightly downward on the tongue wheel, the nested tube is moved to rest on the ground and the pin is inserted. The tension produced by raising the tongue a few inches then stabilizes the trailer and prevents rocking back and forth of the parked trailer.


It is easy enough to attach and detach; I can store all the parts in the galley while on the road.
Once the cabin is assembled, there remain many details before it is ready for camping.

Tom

[tony.latham]

I am thinking that shrinking is not a factor in fiber glass? Unlike cotton fabrics where water can alter its properties, glass is an inert matrix?

As Jake says, glass in the plate form or cloth form doesn't shrink, and water doesn't affect it.



It stays put and doesn't move.

Tony

[jakejakejake]

I would avoid the softener at all cost as its likely to leave a residue on the fabric and affect the glue bond.

Love the stabilizers, any excuse to weld is a good one!

The painted exterior walls look great to me, after all we are building these things to camp in, I doubt the wilderness cares about a few finish imperfections.

[GPW]

Ahem !!! " Unlike cotton fabrics where water can alter its properties " My cotton fabric was well glued , and painted and has lasted 10+ years sitting Outside , through the local deluges and Hurricanes...
As we found out (the hard way) most commercial trailers barely last out their short warranties ...

[tomhawk]

Ahem !!!

I was talking about the canvas before it has been properly glued and painted. Getting unwashed new canvas wet will likely shrink it.
I agree this would certainly not be the case after it was glued and painted.

I mounted the spare under the tongue. I used a scrap piece of 1.5" angle, two 1/2" bolts with some old bicycle inner tube segments for pads to secure the wheel. This increased the tongue weight to nearly 100 lb. This exceeds the recommended 15% total weight but is well below the maximum weight for my tow vehicle. It seemed, if anything, to improve the trailer tracking on the freeway probably since it boosted the trailer weight.


The hatch is attached with an ordinary stainless piano type hinge.
To deal with water flowing through the piano hinge supporting the hatch I made a flap to cover the hinge area from the overhanging edge of the canvas covering the rear roof foam segment. Note the hole where the drainage from the under hinge gutter can exit.


Once the canvas paint dried, the fenders were bolted on and the side running lights were installed.
With no further excuses, we went on our first camping trip!!!
It had been nearly 5 years after starting this project.

From 10 feet it looked OK. From further away it looks a bit better.

Far away, even better!


Needless to say, work on the trailer was not finished.

Tom

[jakejakejake]

As we found out (the hard way) most commercial trailers barely last out their short warranties

Thats no joke! I had a 40' toy hauler in a previous life that I lived in full time traveling for work. The best it ever looked was the day I bought it, and over the course of a couple of years it slowly degraded into a hot pile of garbage. I spent 6 months doing repairs to sell it and get out from underneath it. Now I just feel bad for people with commercial RV's.

With no further excuses, we went on our first camping trip!!!
It had been nearly 5 years after starting this project.

WOOOOOO! Congrats Tom! I am green with envy this morning. I long for the day that my project is complete enough to be able to use it in between finishing all the details.

Spring is just around the corner!

[ghcoe]

The gravity issue is certainly aggravating for me when you are trying to glue canvas to underside of an object. It keeps getting unglued. My solution was to use lots of thumbtacks. Flipping over would be a big help. I think my bigger problem was due to canvas shrinkage.
I can imagine if canvas is glued to a convex surface when the canvas shrinks it just compresses itself onto the foam. Others have described this as tightening up the structure. This seems like a desirable feature. On the other hand, when applying canvas to a concave surface, the shrinking canvas is induced to lift off the canvas producing bubbles. I am thinking that shrinking is not a factor in fiber glass? Unlike cotton fabrics where water can alter its properties, glass is an inert matrix?


Tom

I had a bit of that problem too with #1. Once everything is dry I use a syring needle and poke a hole on each side of the delaminated area. Then I inject some 50/50 TBII/water into the bubble through one of the holes. Then I work the solution into the void till it starts to come out the other hole. Might have to work it a few times over a couple hours. The 50/50 mix softens the canvas and makes it flexible again so it can reform to the curve. On my current builds I pre-canvas the interior walls and ceiling panels. Makes things a lot easier.

You build looks great! George.

[tomhawk]

On my current builds I pre-canvas the interior walls and ceiling panels. Makes things a lot easier.

I agree this is an important technique to use wherever possible. Applying canvas onto a horizontal surface, with good lighting, makes it easily possible to do a perfect job. When adding to the surfaces on the assembled trailer it can be very awkward. It may be hard to see properly and a ladder or step stool might be needed.

I grew up in an urban area. I had a few possessions walk away. I learned that the nicer something looked, the quicker someone would take it. I have since learned that rural places are no better.

Years ago we visited Amsterdam where bicycle theft is rampant. I noticed people would never consider parking a nice looking bicycle outside. Everyone competed to have the junkiest looking (albeit properly maintained) bike; they last longer. Maybe this trailer is safe?

I am glad I resisted adding more windows. The windows in the doors are plenty for our needs and climate. We don't spend time in the trailer during the day. The plexiglass window panes can be removed for better air flow and stowed between the wall and the cabin mattress.

We bought a rechargeable fan to provide ventilation during warm weather that can be hung on the window space. We have used it only once but it ran all night and still had enough charge for more nights. It has a USB port for charging that allows topping up with electrons en route.



Although the window screens work perfectly to exclude biting bugs, I noticed at the height of summer bug season, there are plenty of very small bugs that can still get through.

To paraphrase JBS Haldane:

"God must have an inordinate fondness for insects. He created so many varieties!"

To weigh the trailer, I lifted each wheel over an ordinary bathroom scale. There will be a small error(2-3%) if the opposite wheel is not raised by the same height to keep the trailer level. The sum of these two weights plus the tongue weight is the total trailer weight. The weight on each wheel was well within the capacity of the scale.

The final total weight of the empty trailer is 510 lb. The weight minus the tongue is 410 lb. Since nearly 60 lb are the wheels, this means the weight supported by the axle is only 350 lb. I can haul plenty of stuff without exceeding the axle rating (800 lb). I am concerned that I should have derated the axle even more. I suspect this axle is still a bit too stiff for the weight of my cabin.

If you have ever noticed an empty boat trailer bouncing down the road behind its tow vehicle, that is what is to be avoided.

A major benefit of low weight is the ease of setting up a camp site. Either my wife or I can lift the tongue and maneuver the trailer as needed by hand to the optimal parking location.

Our current vehicle is a 2011 Toyota Sienna with a towing capacity of 1500 lb. On our first few trips I was very apprehensive as we drove faster and thus avoided interstates. In time, fears were overcome and I discovered that the trailer tows nicely at speeds over 70 MPH. On our trip to the Grand Tetons in late summer 2022, we got over 18 MPG (about 10% reduction). We had no trouble passing slower vehicles over 9,000' mountain passes. I am feeling confidant that when we downsize to a new vehicle we will have many choices in models that will be able to tow such a light trailer.

Getting ready for this trip, I discovered another feature about the Dexter axle. I have repacked many a bicycle hub with grease. Lubing the trailer hubs was much easier. No dissembling needed. You just squirt some grease into the grease fitting. That alone already justified much of the extra cost of the chassis.

I am noticing some damage to the fender paint job from road grit and pebbles. I am happy with my choice of "jeep" style fenders. The flat surface comes in handy when you least expect it. After a three day journey from Iowa, when we rolled into our camp site in the Tetons, the license plate fell off. Other than that, this trailer is holding up perfectly.

The canvas-foam composite structure is remarkable. It is really sturdy. However, I hope we don't test a deer impact.
That clearly replaces the frozen turkey at 60mph as a menace.

The temps dropped into the high 20s F some nights in Jackson Hole. This was not unexpected as I had experienced snow there in August. We were very comfortable, surrounded by 2 inches of foam insulation. Each person at rest produces 100 watts of heat. It is a bit shocking to open the door in the morning to feel the temperature difference between inside and out and see ice in the water jugs left on the picnic table.

Tom

[GPW]

[tomhawk]

As noted elsewhere these trailers are never "done". They are works in progress.

Gas Struts
Initially I used some sticks to prop the galley hatch. Gas struts seemed like a great improvement. I tried to figure out a way to determine what was needed for this. I think this involves some vector and torsion geometry calculations that are beyond my ability or patience to solve. There are web sites that claim to provide calculators for strut selection that were beyond my comprehension. It ended up being almost trial and error.

Oversimplifying, I reasoned the lifting power of the gas strut needs to be enough to raise the hatch by overcoming the torque at the point of its hatch attachment. The weight on the edge of the hatch extended parallel to the ground was 11 lb. The distance of this edge from the hinge was 54". To provide the torque necessary to overcome gravity, if I placed the strut attachment at 12" from the hinge it would need at least 54/12 x 11 lb = 50 lb of capacity or something like that. The angle of the strut from vertical is probably an important part of this calculation, but I chose to neglect that significant factor.

The distances from that point to the lower attachment point when the the hatch was opened or closed needed to be within the compressed and extended lengths of the strut. I ordered a gas strut with these length and weight properties.

By making small adjustments on the strut attachment spots I found a combination to make the hatch open and close appropriately. The hatch would remain closed when shut, slowly rise when I initiated opening, and remain elevated when opened. In the end, this was yet another example where perseverance overcame incompetence.

The strut attachment point on the upper hatch was part of the hatch plywood skeleton.



The lower attachment point ended up being the wooden galley counter top. Attaching to a wood insert in the foam wall was not robust enough (I tried. See repaired damage in upper left of picture).



My next job was to think more about an electrical system. This is something I should have been more serious about earlier.

Tom

[twisted lines]

So I m borrowing this one A little bit

A foam fragment attached under the hinge forms a gutter to channel any water off to the the exterior

[tomhawk]

The foam gutter is the idea from ghcoe's #1.

I am thinking of trying this as alternative to the foam gutter. Or maybe even as an addition (think belt plus suspenders). This would be a bicycle inner tube sliced open so it would become a 5 foot long band of rubber. It would be attached under the the length of the hinge spanning the gap between the wood cross pieces. It would channel water leaking past the hinge from above to the exit hole on the side of the hatch top.

Here is a cross section view of my plan:



Has anyone tried something like this?

Tom

[tony.latham]

Struts...I think this involves some vector and torsion geometry calculations that are beyond my ability or patience to solve.

Easy-peasy, thanks to Dan Lott:

https://www.tnttt.com/viewtopic.php?f=21&t=58263&hilit=gas+strut+calculator

Tony