Battery and Battery Holddown

We've had the battery for some time, but its installation has just been completed. After the tongue box and spare tire added significant weight to the front of the trailer, we decided to move the battery to the galley. This required running a 10ga wire down through the bottom of the trailer and along the frame to the tongue box. I'm still not happy about that, but it should be fine. The battery itself is 55 lbs. and it would be catastrophic if it started bouncing around without restraint. It is held in place by two massive pieces of purpleheart epoxied to the galley floor. The vertical piece above the battery is a cam with a turnbuckle to tighten. It is connected to a structural beam above. The flat plywood is to distribute the load and not crack the battery case. The leads from the battery go to the terminal block on one of the purpleheart cleats. The ground goes straight to the tongue box, while the positive goes through a 30A circuit breaker first.

Tongue Box Painting and Hardware

 The tongue box was painted with the same paint as the exterior of the trailer. The interior was given three coats of spar urethane to protect if from contents banging around inside and any UV. The hinge is a 30" brass piano hinge held down by 30 8-32 brass machine screws through bolted to the lid and the box itself. The seal around the edge is neoprene, and the lip of the box overlaps it by about 1" to protect it. The lid is held down by two elastic pull latches. They are at a bit of a strange angle but appear to hold quite well. The lock is on center and catches a piece of aluminum angle iron on the interior of the front of the box. To minimize any water coming through the hinge, it was laid over a strip of waterproof fabric. Lastly, I installed a small strip of aluminum to protect the rather delicate thermistor on the front of the charge controller.

Tongue Box Waterproofing

The tongue box has been attached! The edges adjacent to the trailer have thickened epoxy fillets to bare the load of the weight of the tongue box and its contents. The outer faces have 2-3 coats of epoxy, depending on the location. The interior has 2 coats of epoxy and several coats of spar urethane. The spare tire is also temporarily mounted on the side to figure out the bolt pattern and length. The tongue box is also proving itself to be pretty strong as well, it essentially hovers over the tongue so this is important if anything heavy is to be put in it. On this subject, the battery has been relocated to the galley to decrease the tongue weight a bit and make the trailer easier to handle. Also visible in the photo is the wires to the solar panel. I would have liked to internalize this but unfortunately this turned out to not be an option due to the size of the conduit. The wiring is marine grade and UV-stabilized so I don't predict any issues with it, it is just a bit of an eye-sore.

 

Roughing Out Tongue Box

 With the warm weather, I've been able to pull out the sheet of plywood for the tongue box and get busy. It was pretty hard to get the whole thing scribed to fit the front of the trailer because of the way the tongue box hangs off of the front and is not supported underneath. In the two pictures you can also see where I'm planning on putting the spare tire, although right now its just resting on some 4x4s. The tongue box has three drains/vent in the floor, one of which is visible in the second photo. The tongue box is also very structural: the plywood is 1/2" ACX, the joints have 1 1/2" cleats and the shape is very resistance to torsion from uneven loading, for example.

Hatch Prop

After reading several stories of gas struts failing pretty miserably, I elected to keep it simple and have a single strut to hold up the hatch. The bottom fits into a sort of mortise socket and the top has a pin that slides into a hole in a block of cherry. I decided to get creative and did some chamfered edges and carved a requested otter on one side and a duck on the other. I'm pretty happy with the results, although the duck does look a bit strange on its side. Oh well, functionality before aesthetics and all that.

Door and Window Trim Complete

 With the trailer outside, the race is on to get the door and windows sealed up in case of rain or snow. The door took some work to get the hinge side of the trim trimmed back so that it would hit the edge as the door opened, but it worked out in the end. For the door trim I was able to clamp it, but the windows presented more of a challenge. I ended up holding it down with drywall screws until the epoxy cured, then removing the screws and drilling out the hole with a counter sink bit. This allowed me to epoxy in teak bungs and then chisel them off flush. It makes for a very yacht-esque look and I'm very happy with how it turned out. The joint between the trim and the glass also got some silicone sealant to minimize water seeping into the joint. This just leaves the access hatch at the front and then the trailer will be completely weatherproof!  

Wheel Upgrade

The original wheels provided with the trailer were pretty dismal and did not include a spare, so it was decided that the wheels would be upgraded to a larger size and better quality. The old wheels had 8" rims, so we went with 12", which gives just over 20" diameter with the tire and increases the ground clearance to about 9". Larger wheels also improve handling and decrease the wear on the hub bearings at highway speeds. The current plan is the mount the spare on the side of the tongue box, although we are planning on rearranging heavy items such as the spare to get the tongue weight ideal.

Moving Out and Solar Panel Installation

We hit a big milestone when we got the trailer moved out of the garage and bolted down to the frame. We lifted it pretty comfortably with four people, so current estimated weight is about 300-400 lbs. It took most of the day to get it aligned, mark bolt holes, lift the trailer off of the frame and moved the frame over, drill the holes, lower the trailer back onto the frame and get it realigned, and finally install the bolts. The trailer is held in place with 7 1/2" by 4" stainless screws, with nylocks and some threadlock just in case. First install in the open air is the solar panel, a 120W Kyocera module. It had been previously installed, but I removed it to keep the trailer as light as possible until it was on the frame. There are four L-aluminum brackets, one for each corner, made by bending rectangular 1/4" stock in a hydraulic brake. The frame of the panel is mounted to each of these with two 10-24 stainless machine screws with nylocks. To mount the brackets to the trailer, I drilled out a hole for each one into a structural member under the plywood. I then epoxied in a fiberglass tube and tapped it for a 1/4" bolt and used it to bolt the bracket on. It turned out very solid; you can shake the trailer by that panel without any worry.

Door Trim Continued

 After epoxying the pieces of the door trim together using the door as a guide, I added a 1/8" rabbet around the outline of the door. Given that if you slam the door hard enough it compresses the seal enough to go a bit past the frame, I didn't want the teak to take any of the impact. I also have constructed the trim around the door window. Unlike the trim around the door itself which I can clamp while the epoxy cures, the trim around the windows has to be screwed in to hold it. I used 8 drywall screws, then took them out after the epoxy cured. To cover the holes, I drilled them out with a countersink bit and put some bungs in them. I'm quite happy with the results, although some of the bungs twisted as I pounded them in and aren't perfectly aligned with the grain. I also added a second silicone seal around the window to keep water from pooling in the edges

Windows Arrive and Trim Work

The windows finally arrived in the mail today. They are both laminated 1/4" safety glass to minimize the risk of breaking them as well as avoid any shards if that does happen. The door window is 11" square and the wall window is 19" equilateral triangle. They both arrived undamaged and fit nicely into the insets for them. While the seal around the door window was curing, I also started to fit the teak trim around the door frame. Teak is incredibly nice wood and I've been taking my time to get it right since it will not be finished. While the oil in teak makes it very difficult to glue or paint, it also makes it pretty much impervious to insect damage or rot. It just needs a coat of oil every year or so to stay healthy.

Beginning Electrical

 Now that all the conduit has been sealed inside the ceiling, it's time to make sure everything electrical is functioning. The control panel inside to cabin is the most complex electrical portion, and that is up and running now. It has the cabin light switch with a dimmer, the toggle for the ventilation fan, and a toggled 12V outlet with an analog ammeter to show current drain. Everything inside is shrink-wrapped, so I'm hoping there won't be any issues although it is pretty accessible if anything goes wrong. The other electrical portion I've installed in the fuse block. It is located on the front of the trailer and will be enclosed in the tongue box. It has six fuses and a ground bar , although I'm only using 4 of them; cabin light, galley light, ventilation fan, and the 12V socket in the cabin. The wiring is all 18 gauge, except for the socket which is 10 gauge. I'm thinking of doing a 1A fuse on the lights and fan, and a 15A fuse on the socket. Right now, I'm running everything off of a 12V 7Ah battery that I found until we have the actual battery for the trailer.

Painting and Beginning to Install Hardwear

After sanding the fiberglass, it is time to paint. The paint is pretty standard latex which has been chosen for several reasons. First, the only practical purpose is to protect the fiberglass and prevent the epoxy from UV degrading. Second, The latex is flexible and won't crack from the trailer flexing. Last, glossy finishes make it incredibly obvious if there is any defect in the surface.  No issues with painting whatsoever. Also worth noting, the bottom has been painted with roofing paint, around 5-6 coats. The bottom ply really isn't structural at all, but it protects the insulation and interior framing so it is worth a few coats of paint to help it last. The galley hinge has been added, too. Teardrop use a special kind of hinge called a "hurricane hinge" which is rumored to be completely waterproof. It is made out of two pieces of extruded aluminum which sort of nest inside on another, making it removable by sliding the hatch laterally. To prevent this when not intented, I drilled and tapped a hole on each overlapping end and put a stainless machine screw through. I've been scared to death that I'd bend the thing and make it useless, but it seems to have survived. The outer portion sticks out about 3/4" on each side when installed to prevent any water from coming in the side and going between the two pieces. Also it is the door striker, which is a peice of 3/16" 316 stainless through-bolted to a beefy stainless backing plate.

Standoff Blocks

 Due to the design of the frame, there are several bolt heads sticking above the longitudinal members and the lateral members are inset about a quarter of an inch. To compensate, I cut out some purpleheart standoff blocks for the trailer to sit on. There are two full width pieces, on the rear rail and on the second from the front. These each have 4 3/8" stainless machine screws going through them to attach the trailer. The other two rails each have two small blocks with are positioned under the floor beams to help distribute the weight.

Galley Cabinets

 Storage in the galley is a little inconvenient due to the shape of the available area. I put a couple of cabinets in, with a sliding door compartment and a little shelf above it. The area is trimmed in cherry and there is a nice thick trim piece for the counter edge to stiffen it and protect the edge grain. To keep the cabinet doors closed, I put in a small S-shaped piece that can rotate and hold them both.

Hatch Skin

 The galley skin is 1/4" ACX ply with the grain oriented horizontally. I originally had some doubts as to whether the plywood would conform to the bend or distort the frames enough to affect the seals on the edge. Happily, there were no complications of any sort. The outer face is fiberglassed and the inner face is painted, although I've left the ribs bare for now.

Finishing Fiberglassing

 Not really much to say here, just finished fiberglassing the front/top and the door.