Time for the Bop-A-Tear

[KCStudly]

Very nice work.

[Hepcat]

Two more weekends, and i have made grrrrreat progress. The second side wall frame is done, they have been aligned and look identical, both side wall interiors are practically skinned with 4-5mm ply that was lying around being leftovers of dismantled furniture that my grandpa built 40 years ago.

first side wall on a stand, some bits of the second wall arleady on top

The darn glue wouldn´t cure outside, so I brought everything into the house (the workshop being too small for the wall once assembled)

This is how I applied pressure to the glue points since i could not lay down the whole wall and put weights on it

Both walls identicalized...or so. They are the same. But they both need some grating before I can put them up on the trailer bed, once I have the base plate stabilized.

[KCStudly]

What I have found when using clamp cauls like that is that you get good pressure under the clamps, but due to flex in the caul and a lack of backing in the work piece you might get uneven clamping, including little to no clamping in between clamps.

An improved... though more involved technique... would be to shim the caul up at either end so that there is say 1/4 inch gap (5mm), and then use wedge shims all along under the caul. That way you can control the amount of clamping force at each wedge and spread the backing force of the caul all along the joint. In your case where you are not backed up by a work bench, you would want to clamp a second caul on the back side of the work doubling up the front side caul. Otherwise the wedges could warp the work piece into a bow shape. I used this technique to glue my roof spars to my ceiling skin prior to installation and it worked well; http://www.tnttt.com/viewtopic.php?p=1085357#p1085357.

[Hepcat]

Interesting technique. I used some shims in between the large screw clamps where the skin would not directly adhere, but I am not worried about warping the wall. It´ll straighten itself when all the furniture and the wall to the kitchen is in place.
Next will be getting the base plate straightened with some aluminium U-profiles, then I can mount the walls testwise

[Hepcat]

It´s been a fairly quiet week on the western front, mainly due to the effin´cold over here which prevented me from doing more than just routing the door frame on sunday. There were some spots which needed improvement for the door to seal properly and get a flush alignment with the outer skin...

Like this, for example..ok, not quite finished as I had to beef up the frame a bit and now need to sand it down again

or here. The ply in the door cutout is from the other side wall which I stored just behind the passenger side wall

Now, I really need to get the trailer bed stabilized, but I won´t manage this until maybe April, as I have a trip to Africa coming up.

[Hepcat]

Allright, Y´all, time to get this project resurrected. It´s only been 4.5 years since the last entry, but divorce, moving home (twice) and other sh.t got in the way somehow...dunno why.

Anyways, I had the trailer squared away somewhere (mind, it still isn´t registered and therefore road legal) and have been scraping my pennies together to get it at least through the technical inspection. This involved getting new tires, painting the rims, re-doing the electrics and sticking reflector foil to some surfaces, bolting down the base plate necessitating a several weeks long search for just that one missing counter plate, installing the attachment points for the clamping screws and a million other things. Not even mentioning that the trailer currently sits in a multi-storey garage and all the wood needed to continue sits on it in a big heap and must be removed to do anything. My son is already cursing me big time...

So yesterday I went to the technical inspection, and as hoped the inspector was the same guy that gave me valuable advice 4 years ago. Even though sympathetic to my endeavors, the trailer didn´t pass. Well, that´s not quite correct, the inspection wasn´t really started BUT there are only a few minor things to be corrected before I can try again in January, such as:
- positioning lights on all 4 corners
- number plate mount with lights
- corner protectors for the rear end of the base plate
- most importantly, a kind of deflector grid at the front end of the base plate to prevent persons stepping in between tow vehicle and the (very low) trailer to have their knees cut in two when the whole thing moves forward

So that doesn´t look too bad. Picture will follow!

[NevadaBlue]

Excellent news to hear that the build is still in progress. Makes me feel better about my year old effort. Watching...

[Hepcat]

So, as could be kinda expected in these trying times, nothing goes quite as fast as hoped. DIY stores were closed for a long time, I had another move going on.. finally settling in a nice place with half of a double garage just about suitable for my purposes, even though this means I have to drag the trailer out every time I want to do some work...
So this is what the workspace looks like right now:
Even with a tool wall in its infancy

Back to the trailer. I needed some serious thinking to come up with solutions for the deficiencies pointed out by the German technical inspection. One was the possible excessive tongue weight, which must not exceed 75kg (about 165lb), since the axle is fairly far in the back of the trailer. I wasn#t worried, since with the box on top, the heavy kitchen was in the back, balancing the tongue, but I wasn#t going to tell that to the inspector, since I want the trailer registered as an empty flatbed. So since I thought about a drop floor beneath the kitchen anyway, I decided to make this an underslung storage compartment accessible through two side hatches. This is the compartment during assembly:

I had to cut out quite a bit of stuff since longitudinal frame beams run underneath the flatbed, and it took me three corrections to manage something that would indeed fit underneath, so here´s the result:

Now even in empty configuration the tongue weight is down to 55kg / 125 lb

[Hepcat]

So this summer has seen a MAAAJOR advance: I finally got the empty trailer through the technical inspection and had it registered! Yay! After all we did to it to satisfy the inspector's perceived shortcomings, it passed with flying colors.

Issue #1: excessive tongue weight. Solution: put more weight behind the axle with an underslung storage compartment.

This is what it looked like before mounting. Dreadfully complicated to build, as the underside of the bed is quite complex shaped. After mounting:

I had to find the correct position as I needed to screw through the bed and hit the 15mm (0.6in) walls with my screws, so I drew the positioning on the top side of the bed. Didn't work 100%, but so what.
Issue #2: deflector
The tech guy thinks that someone standing in front of the bed would have his knees crushed when the pulling vehilce takes off, and he couldn't properly see the low trailer bed, i.e. at night, so I manufactured and mounted an angled aluminium U-profile...


...which I immediately removed again after obtaining registration, as it is completely pointless with the cab on top of the flatbed. More progress coming to this theatre soon!

[Hepcat]

So issue #3 was the positioning lights. Those were easy to obtain, but the wiring was a whole other story...first of all, we needed to decide into which wire to branch into. I did not want to open the insulation of the main wire coming from the tongue plug, so my oldest son (master electronician) decided to open up the housing of the rear lights and disconnect the number plate lighting, use their connection to branch out to the positioning light on each side. This wiring had to run the length of the flatbed underneath the bed, so we put a flexible cable channel with multiple holders in pace, ran the wire through, and sealed it against vermin and splash water intrusion

This rear positioning light was very close to the connection within the rear lights. We still did a cable channel, of about 7in length

This is the rear of the trailer seen from underneath. On the upper hand of the picture is the rear cross member of the metal frame that holds the bed. A part of the auxiliary frame penetrating the rear wall of the underslung storage compartment can also be seen. One cable channel follows the auxiliary frame further to the front positioning lights. The cable channel extending to the right goes towards the number plate lights, which had to be fitted closer to the actual number plate (see below, but barely visible to the left of the number plate)

And here's said master electronician hard at work. A generational effort!

[Hepcat]

Now that the regulatory stuff is out of the way, I can finally get creative and start working on the cab to be put on the bed. The side walls that I had created 5 years ago have not fared well during intermittent storage and needed some serious restoration. I am currently reinforcing the bottom of the frame, since I have to accommodate for the sag of the not-so-flatbed at the rear edges, which are not supported by any frame (the trailer frame being from an ancient camper that had a self-supporting cab). Also I have been working on the dropped footwell.

This is the situation with the maximum size of the footwell already cut out of the bed, being limited by the longitudinal frame members extending into the tongue. One can immediately spot the major problem in the shape of the handbrake cable, which really is a massive 1/3 inch metal rod that cannot be rerouted to the side of the hole. So just assembling the footwell and sticking it to the bed from underneath is out of the question. Still, I have to assemble the footwell pieces on dry land beforehand to make sure everything fits:




This is what the hole looks like from underneath:

Here I have already put the bottom plate in place, with drilled holes and screws in place, then the front and back wall were squeezed in between the bed and the bottom plate and fixed. This also pushed the handbrake cable down a bit, and I will be fitting metal protectors to the front and rear bottom edges of the footwell to make sure that the minimal fore-and-aft movement of the cable doesn't damage the wooden floor. Then the side walls were fitted and glue-screwed in place. And, whoopdee, done! Only took about three weeks...picture proof to follow.

[Hepcat]

So it#s been 4 months since the last post and here's what has happened:

Now that the trailer bed is ready I could finally concentrate on the side walls that i had already assembled about 5 years ago. Time has not been kind to them and a lot needed re-doing, mainly because only one skin side had been mounted and they were still fragile in this condition. So I reinforced the frame, especially at the bottom where it would sit on the trailer bed, and around the door opening, reglued some of the interior skin, then laid both walls on top of each other on several supports and sanded down the outer edge to have two completely identically sized and shaped walls (I wouldn't want to think what might happen to the roof skin if one side was higher than the other...). Then I bought 11 sheets of 4mm (1/8th inch) luan and shipped them back on my flatbed trailer (probably the last time I can use it for that purpose...)


This is what the wall looked like when I put it on supports. The wheel well shape wasn't yet fully defined. The rather strange positioning of the frame member at the very left of the pic is due to necessary support for the screws that will hold the eyeplate to hook up the clamping screw to hold the whole body down on the flatbed. Won't be seen once the outer skin is on, but rather useful, I dare say.

With this model I will shape the wheel well cut-out. Now for some explaining: the wheels are currently under a black plastic fender that reached out up to the side limits of the flatbed. It will stay in place once the trailer body is mounted. So the frame must accommodate the shape of the fender, but the outer skin will cover both the body frame and the fender (which has a downward-bent outer part). That's why the size of the wheel well cut-out has to be different for inner and outer skin, and here's the model for it.

Another thing I needed to prepare for was the connection to shore electricity. This trailer is not meant to be off-gridded, so I am only installing 230V electricity (with the help of my electrician son), and this is where the connector socket comes in, it is near the rear underneath the kitchen workbench on the driver's side. The fuse box will be mounted to the left from the inner wall, so there has to be an additional vertical member to receive the screws

Now for the fun part: Insulation!! I am a big fan of renewable building materials (having used them when I restored an early 20th century house), so I opted for sheets of woven hemp fibers. They come as a roll of 1 m width, 10m length and a thickness of 1cm (2/5th inch). Since the inner frame is 2 cm (4/5th inch) deep, I am cutting the mat twice and layer both bits on top of each other. This material is quite flexible and can be pushed and pried into shape no problem, and cutting with regular sharp scissors is quite easy.

Here the insulation is almost complete, and the outer skin parts can be glued down. One thing that was still missing is...#

...the subframe for the single window (porthole) that will be mounted on the driver's side wall. I got a 12" diameter porthole from a RV supplier here, which unfortunately came without mounting instructions. So I looked at the window seal profile and decided to add 1.5cm to the diameter of the wall hole, shaped the inner frame accordingly and glued that in. Right now with winter time, glue takes over night to set, so work is rather slow...

[Hepcat]

Compared to the first 5 years of build, this project is now moving at lightning speed! The driver side wall has been insulated, openings for shore electricity and bull's eye window cut out and all subframes assembled. Let´s get the outer skin on!

The trailer side is about 11' long and 4.5' high. So no way I can just use one panel for the whole side - I need to assemble the outer skin from various parts. The size and location of the individual panels is dependent on the positioning of the inner frame, since I need to glue down the outer rims of the panels to a frame member all around. I decided to use 4 panels in total, all could be oriented with the grain running horizontally.
The first skin fragment covers approximately the rear third of the box, i.e. the kitchen and half of the dinette inside. Clamping that one down already needed some innovative techniques with shims to achieve even contact to the frame.

Next is the front upper panel, whih is actually the largest panel used, with about 7' length and 3.5'height. Clamping is even more of a nightmare. I think I used 23 grips and clamps here...

Looking pretty good already with the third panel (bottom rear) being fixated. Where clamps wouldn't hold anymore, I used sheer weight to press down the skin. The whole side turned out fairly sturdy, not much sag in the center.

Now we're getting there. Last panel needs some fine-tuning, shapewise...

aaaand...done! Ready for THE MIX!

So I have been lacquering for the last week or so...One coat each of The Mix 25%, 50%, 75% and currently 2 coats of PU 100%, each coat sanded down with 240/320 grain sandpaper in between. The picture shows the drying process of the first coat of The Mix. Tomorrow I am going to put the trailer back in the garage for a week (due to business travel), then the interior wall will be painted in ivory and the window and socket fitted. BTW, this is what the interior looks like right now, and you'll understand the need for a coat of paint:

[Greg M]

Great to see your making progress again.

[Hepcat]

We are getting close to mounting the first wall! After a short break for business travel, I have painted the interior wall and mounted the eyeplate that will hold the upper end of the clamping screw and thus fix the cab to the bed. Furthermore, I routed the inner part of the wall of by about 1/2", so that the roof spars and inner lining will overlap into the side wall (should make it easier fixing the inner roof lining and not have sag)
a little helper to mark the limits of the routing

free-hand routing in progress...needed multiple parallel runs

ledge is looking pretty good already

my little helper to avoid the router going hogwild. This way I can slide the helper along the outer edge of the side wall and get a ledge of equal depth. This has to hold the spars (1") plus the roof lining (3/8"). In between the spars will be insulated with the same hemp mat used in the walls

sealing the underside of the removable cab against the bed with rubber band (self-adhesive plus screws)
Note to self: do not paint before using the router...