Norm's Trailer

[Honda03842]

Floor Weight Analysis.


The Sunlines original floor 12x7 (84 square feet) floor is estimated to have weighed 180 lbs. Most of the weight was in the OSB floor. A great aspect of this floor was the full length Aluminum pan that made up te bottom.. I never saw a spot where the aluminum leaked.


The new floor 20x 7' 4” (146 square feet) floor weighs 192 lbs. This is about 10% heavier than the original floor; not too bad considering it is about 70% larger. (By the way there's 12 pounds of adhesive in the floor.)


In addition this floor has an insulating value of about R-11. This is higher than most trailers. The walls will be R-10 and the roof R-15.


The floor also adds to the beam strength since it is all adhesively bonded together as a single unit. Though there are two layers of wood in the floor, thin ¼ inch plywood sheets, the plywood is designed for underlayment in moist areas. Most plywood surfaces have been paint or urethane sealed. The bottom sheet painted on both sides and edges. The top sheet was sealed with urethane, primarily to protect it from the rain and the workers (that's me) during the inside construction.


I did finish putting the top layer of plywood down today between the rain drops but did not manage any pictures before it really came down. Tomorrow is expected to be nice and pictures of the completed floor will be posted in the evening.


Tomorrow I plan to locate the inside structure with blue painter's tape and install the water pipes.


Update.


In the previous post where the foam is in place I neglected to mention the white streak that runs the length of the trailer. That is a 2” x1.5” x 20 foot homemade wooden beam with a steel spine sandwiched in the middle. The beam is glued to the bottom layer of plywood and screwed from underneath through all the cross members.

 

[Honda03842]

Floor top layer

Yesterday I completed the top layer of plywood on the floor. It rained so hard I didn't get to take pictures though I did get to urethane the surface. The rain just puddled on the fast drying urethane I used, looking like a freshly waxed car.

 

[Tweety]

Keep a the pictures coming Norm...looking good, and we're enjoying following along.

 

[Honda03842]

Family Weekend.

Didn't get a lot done other than putting down blue tape marking the positions of internal cabinets and other structures. Of course an approach to a trailer as wierd as ours continually results in a lot of changes and think time.

Today we sat around and considered the next phase, walls. We mocked up a little corner from some left over floor material. Our trailer seeks lightness and the walls are to made of 2 inch foam.

Once the foam goes up the inside and outside will be painted white, sort of like a primer.

When done the outside will be covered with colored vinyl. On our practice corner we put a small piece of teal and a piece of chrome.

We bought some vinyl for a test early in the year and mounted a piece of 'pink' foam on the front of Honda with vinyl on it. We drove some 3000 miles without any issues. Today I mocked up a corner, gluing two pieces of foam together. I then rounded the corner of the foam by hand sanding it. I than attached two pieces of vinyl to the foam.

This vinyl comes in a whole field of colors and seems to stay in place. They actually make some specifically for covering entire cars. We had originally thought we'd like the chrome until we drove behind a truck with a chrome rear door. It seemed to be too much. We'll probably end up buying lots of colors, for stripes and the like.

The inner surfaces will be colored, either with paint, with wall paper or paint and wallpaper borders. We're leaning towards light greens inside leaving the ceiling white.

 

[Honda03842]

I've received a number of comments about the use of foam for the walls, people concerned about the strength of the foam.

Two inch thick foam is relatively stiff but is really stiff when you recognize that every wall has floor and/or overhead cabinets that are effectively the source of reall stiffness. As well all overhead cabinets go directly to the floor or are supported off other cabinets that do go to the floor.

As well every piece of foam is bonded to the next at it's sides, at the floor and at the ceiling, it's essentially a one piece foam box. Each piece of foam fits into a metal groove at the floor. As well there are cross steel members in the ceiling; steel cross members are bonded to the side walls and the ceiling foam.

My major concern is applying the vinyl to the sides of the foam without ripples. Seams between rolls of vinyl will be locations of stripes reducing the need for perfection.

By the weekend I hope to have up the walls and ceiling.

 

[Honda03842]

Learning

Today I began repairing the original door.

When I removed it I could not believe how heavy it was. My wife always thought it had a steel core.

It turns out it had a foam core, that white foam you see at the box stores. It turns out that the white foam absorbs water. It was loaded with water, the source of most of the door's weight. The foam (pink or blue) I'm using to rebuild the door does not absorb water.

 

[Tweety]

Did you investigate how water was getting into the foam? When we open Tweety's door after a rain, some water always drips off at the bottom, and there's always a puddle on the sill plate. I wonder if we need to investigate this.

 

[Honda03842]

I didn't bother to look but the aluminum frame is not continuous and water could leak in. As well, though their is plenty of sealent around the window, their is none on the edges of the door frame and plastic top sheet.

Of course your drip could be just surface moisture. I was simply shocked by the weight of the door.

The door way is a weak area at least in our trailer. I've heard others talk about cracks around the door, some kind of indicator.

The outside frame of our doorway, welded aluminum, had cracks in the welds, indicating stresses at the doorway. Again ours is an older Sunline and hopefully it's something they picked up on over the years.

 

[pextron]

Your project is looking good and it's nice to see someone thinking outside the box as I frequently like to do myself.

I can see that you have done a lot of planning and have put careful thought into your design and find it interesting that you plan to use foam as structural wall panels, although I am not entirely certain how you are bonding the panels together at the seams and corners.

It's important to remember that the structural characteristics of foam panels are very simililar to those of concrete, which is strong when placed into compression but weak when placed into tension. If you can manage to keep the panels bonded tightly, you should have a relatively strong, yet lightweight design.

However, I am a little concerned about your use of aluminum for the framing members. In particular, the way in which it is bolted together. Over time, as the frame flexes (known as cyclic loading), which is amplified at the rear during travel, it is possible that fatigue cracks could start to develop at the bolt holes and propagate outwards until the structural framing member fails. As you mentioned earlier, galvanic corrosion is a potential problem which you addressed, although I believe galvanic corrosion is likely to be prevalent where the bolts penetrate the framing members and could potentially contribute to the formation of fatigue cracks in the framing members.

An example of fatigue failure is Aloha Flight 243, where cyclic loading combined with corrosion, caused a mid-flight failure of the aluminum fuselage, resulting in part of the outer skin being blown off while the plane was in flight.

In any case, and despite my concerns, I think you're doing a great job.

 

[pextron]

One way you could keep the foam panels in compression is by using small steel cables as cross bracing tied to metal corner plates. It would look something similar to the cube example below.

 

[Honda03842]

We had originally considered using pallet strapping to wrap the trailer when we were considering using two layers of foam, each 1" thick. When we went to 2" foam we abandonded the idea.

One thing I learned when I dismanteld our Sunline was the importance of the cabinets to the structure. The walls and floor were only an inch thick (speaking of insulation and I could rip the aluminum like paper, more difficult but easy to do.

The trailer walls wobbled like jello without the cabinets. In my trailer design the cabinets are structureally important. The foam hangs off the cabinets, not the other way around. Every inch of the wall/ceiling has a cabinet (might we say box beam, most of them overhead cabinets. All over head cabinets are grounded, never hanging off the wall or ceiling though bonded to both wall and ceiling.

The floor cabinets do not go all around but do go every where but the doorway and the sides of the walk around bed. The walk around bed is a box beam itself stiffening the rear section of the trailer. The pantry cabinet over the end of the bed goes floor to ceiling and also connects to the side walls.

As well the rear cabinets at the head of the bed are floor to ceiling in each corner and the overhead cabinet at the head of the bed hangs off the corner cabinets. Another stiffener is the kitchen counter is a little different from the typical trailer in that the ends of a counter are not fully open. The ends have a beam that runs floor to ceiling, either an end floor to ceiling cabinet or a simple floor to ceiling box beam. The rule is all overheads are grounded to the floor.

My design assumes that the cabenityry will stiffen the whole structure.

Foam panels are held together with polyurethane adhesive. The tongue and groove joints will not fail at the adhesive bonds. Failure occurs in the foam not in the adhesive.

While I'm at it the doorway was a real structural issue in our trailer. Actually the corner welds of the aluminum door fram had all failed causinvg the door to go out of square. I intend to restablish the frame reinforcing the corners with aluminum and running a 1" box beam of aluminum under the door. Beside the door I will have a 2x1 Floofr to ceiling bean on each side of the aluminum. On each side of this frame I will have a 5"x1" floor to ceilin" g to provide additional depth to the door. The 1x5 member on the kitchenside will become part of the kitchen counter. The 1x5 member on the living room side will be part of a chair rail height cabinet. It will capture one end of the overhead that runs to the front of the trailer.

The ceiling is 2" foam with a curved wood frame bonded to the top of the ceiling. A 1.5 inch piece of foam is bonded to the frame and 2 inch foam. As well wall board, 50 pound plastic spiral picture mounts are screwed into the 1.5 " foam into the 2" foam to hold the two pieces together. The roof is really stiff. Wiring runs between the two layers of foam. The curvature amounts to a 1" bend. The 1;5" pieces of foam are sesigned for wood lathes; I use this feature to over lap edges of the panels, putting adhesive on both surfaces. They do not leak; we've had plaenty of rain.

I believe that once the cabinets are installed, I'll be able to a carefully go onto the roof.

I view the side walls as being strong if they are not allowed to bend. Preventing bending is the function of the cabinets. In most cases the cabinets cut the span of the side wall, in many areas they reduce it to zero.

The front wall of the trailer is still undefined. Like Frank (of homebuilt trailer) I want to make the front if the trailer a smooth curve though I could do as he did and SUnline did and make it a linear approximation.

It will be one of my last steps because I intend to leave the front open until I get most of the cabinets built.

I agree with your thoughts on the frame extension and in my heart am wishing I had built the frame from the ground up. I am considering further strenthening it by increasing the thickness of the two side beams.

As to galvanic action I uncovered some in the dismantling of our trailer. The bottom of the floor was aluminum resting on steel. After 28 years their were a few spots where the aluminum had been eaten away. On the whole is was intact though it did leave a slight pattern from it's corragations on the steel. I should mention that there was no treatment to prevent the galvanic action possibly other than paint. If it lasts 28 years I'll be happy. I definitely will be checking it. I do an under trailer inspection (and painting) at least once a and will keep an eye on it year. (I am rust paranoid and just keep repainting . Many of our trips includ dirt roads and leading edge surfaces take a beating.)

I'm sure I've made mistakes. Everyday I sit there and see how it could be better, what I've done wrong but that is life. Two of my favorite movies are Blade Runner and Groundhog day. In Blade Runner the robots are upset that their lives are quickly terminated and life is short. Might we have the same complaint with our God(?). (I'm not trying to make anykind of religious statement, just a simple thought.) In building this trailer I bemoan that this is probably a one shot adventure; at 67 I doubt I'll do this again.

Ground Hog Day is marvelous because he get to live each day until he learns the lessons. The best of us considers our actions, past and immediate, using them to improve future actions. if life were longer we might be better human beings. Definitely I'd be capable of building a better trailer.

Though I haven't posted any pictures recently I have 80% of the walls and 50% of the roof and ceiling up. Each night I am dog tired but I do plan to write everything up.

By the way with respect to the frame I have one undescribed feature of this trialer intended to increase stability that should further stiffen the situation.

For years we had a cast foam canoe that used to be attached to the ceiling of our apartment (actually over the bed) for storage. This onepiece canoe was marvelously light and handled well. I wish I had been smart enought to cast the trailer. The canoe had one piece of wood emnedded in the casting for the keel protection.

The canoe was inspiration.

Wow I can be wordy,

 

[Honda03842]

Unfortunately I have not taken the time to write much but do promise to right an extensive document when I'm done. I'm soon to be 68 and admit though I feel stronger than when I started this project, I'm truly tired at night. I haven't been this tired since I worked on shade grown tobacco as a 15 year old some 53 years ago.

Except for the front, which we intend to leave mostly open until we near the end of cabinet construction, we have built the basic structure and are in the process of priming the outside and inside of the unit. Once primed we will give it a coat of white paint.

As we proceed we will give the inside a final coat of paint or wall paper where appropriate. The following picture shows the trailer box mostly primed. The two wooden members on either side of the door way are there to provide structure for the door and overhead cabinets that will be located above the doorway and on either side of the door way. All overhead cabinets are directly connected to the floor via floor to ceiling cabinets or wooden columns like these.

The next task is to install the windows followed by the building of the cabinets.

 

[pextron]

Looking good!

 

[Honda03842]

This is the last of the roof panels. It is held in place by our sidewalks granite paving stones until the adhesive dries. As well large diameter plastic screws connect it to the ceiling pane at the edges.

There is a curved wood frame between the 2 inch thick ceiling panel and the 1.5 inch roof panel. The roof panel curves about 1.5 inches thought the leading edge of the last panel is only about 3/4" above the ceiling panel to ease transistion to the front foam pieces.

The front will consist of two inches of foam. It will form a continuous curve from the floor to roof. The curved section will be two layers of 1" foam. To Hold the curve it will fit into a track top and bottom. The curve maximum extension the curve is about 12", a relatively easy bend for the foam.

Twelve inches is equivalent to the original front extension on our sunline though on our Sunline it was not a curve but rather a linear 3 step linear approximation like most Sunlines.

The upper portion of the front foam will be also supported by a full width overhead cabinet and the bottom portion of the foam by a full width chair rail "like" shelf.

The lower portion of the foam will be protected by decorative sheet aluminum.

 

[Honda03842]

Frank and friends,

I've begun building the cabinet frames using the Kreig Jig. Framk thank you so much for the suggestion. It is one of the neatest, easiest to use tools.

I began by making one side of the bed's frame, a 20 x 75".

Each side of the bed has four 14" wide x 18" deep by 7" high draws located in about the center of the frame - 2 over 2.

Each side has a clothes Hamper located where my hand is. The hamper is 12" wide x 12" deep x 16 inches high.

The opening in the frame at the other end is the location of a bedside cabinet. This cabinet has four draws and a hanging closet above it. I hope to build one of those cabinets tomorrow.

My young neice took this picture catching me after painting the primed outside with semi gloss white. It was 90 and very humid today and I really felt my age today.

 

[frank-SUN]

Norm,

I'm glad you like the jig. Honestly, I'd be lost without it on this build, and about a month behind too!

Keep the pics coming!

- Frank

 

[Honda03842]

Frank,

If I had known about the Kreig jjig I would have bought one 40 years ago, It's as valuable as a hammer. The best $30+ I have spent.

It;s amazing how rapidly I go thru screws and most amazingly how stiff everything comes out. I have built the frame pieces for the bed, bedside 4 drawer cabinets, and two hanging closets. I have also started the pantry. I suspect, weather permitting I'll finish all the cabinet frames this week. I really can't believe it.

I'll take some pictures tomorrow. We've decided not to install any of the cabinets until we paint the final coat of paint, so far primer and a top coat of white.

As to drawers, some 37, I'm considering using an automated drawer company.

Thanks again for the Kreig suggestion.

 

[Honda03842]

Bedroom

I've made most of the pieces for the bedroom. Tomorrow Ginny will give the walls their final coat of paint and I can begin installing the furniture.

The picture below gives you an idea of what we've done.

This is a traditional walk around bed with a four drawer cabinet on each side of the bed. Each side of the bed also has four drawers and a hamper. (I've never had a personal hamper before.) This all provides 16 draws in the bedroom.

Sitting on the 4 drawer is an 11 inch wide hanging closet. The hanging closet on the right is on top of its cabinet; the left hanging closet is sitting on the floor. They are rather small but the 5 foot wide window to be mounted in the rear of the trailer limits their width. Fortunately we don't carry a lot of hanging things and there's an additional 2 foot wide hanging closet in the living area.

Between the two hanging closets and over the window will be a full width overhead cabinet with two bays.

The frame on the end of the bed is our "over the bed counter and pantry" (It actually hangs over our feet. It has 4 overhead cabinets that open into the kitchen and two under counter drawers in the foot of the bed that pull out into the kitchen.

The counter and it's support is not yet in place ibut will be near standard counter height and provide four linear feet of counter space.

In addition to this counter the basic kitchen counter has another 6 feet of counter, 2 feet for the sink, 2 feet for the stove and 2 feet of open counter. The kitchen will be located to the left sode and the bathroom to the right.

We have become indecisive on the living area. Originally it was a couch with an easy chaair now we're leaning to an L shaped couch, across the front and along the side with each segment about 6 feet long.

The rear of the pantry will have a bedroom TV mounted on it.

 

[Honda03842]

Drawers.

We have some 40 + drawers to make. Today I ordered 40+ sets of travel lock drawer slides on line for about $3.30 a piece.

Originally I had thought about having the draws made bya third party but today my son dropped by with his table saw and we cut a bunch of 5 ply plywood up for the drawer sides, dadoing (sp) a 1/4 inch slot in all of it for the drawer bottoms. The bottoms are 1/4 inch plywood.

We built a first drawer (picture in the morning) and in the process decided we could use the same material to create the drawer front instead of the typical "false", non-structural drawer front. The downside is that when the edges of the drawer fronts are routed to provide a round edge you'll see 5 ply lines all the way around.

We can't decide if it will look arty. Ginny seems to accept the concept but we'll no better on Monday when we rout one.

We again used the Kreig jig and Kreig screws along with glue to mount the sides to the front, one more thank you to Frank for Kreig.

 

[Honda03842]

Drawer Picture

This is our first Drawer. This is a drawer for one of the four drawer bedside cabinets. The cabinet is 24 inches deep and the drawer is about 22 inches deep. The remaining 2 inches are available to run wires.

The picture clearly showes the elimination of a false front and the use of the front of the drawer box to from the front.


The front has yet to be routed; router will arrrive on Monday. As well the wood has not been urethaned.