Attaching the walls

The walls are attached to the deck with liquid nails and 1 1/2" #14 screws. The deck was pulled out of the frame and put on a table so I could get underneath to run the screws up from the bottom. The sides are visible on the right side of this photo.

I cut a slot in the deck for where the tails come down to the deck. The slot will give any water that runs down the tails a place to go other then into the kitchen area. The wood here will be sealed with a good waterproof sealer so the water drains out rather than soaking in.

Here are several pictures of the sides after they were attached. A piece of bailing twine was used to tie the sides to the ceiling of the shop to hold them in place while everything set up. I'll build the rear bulkhead before moving anything. The bulkhead will provide shear strength so the walls will stay in place.

Laminating the walls

Here's a couple of pictures of laminating one of the sides. The process was the same as for the door in the previous post.

Grandson Jonathan decided to do a compression test on the sandwich construction.

Laminating the door

I haven't posted for awhile, but work has been continuing. Here I show how the door was laminated. The walls will be done the same way. Wood framing has already been added to the inside plywood. GreatStuff foam goes in the cavity.

Next, the 1" foam goes in and more GreatStuff foam.

Next, a bead of glue on the frame pieces, and then the outside plywood goes on top.

The outside foam is tacked down with small brads (sorry, this picture is sort-of out of order)

Finally, the whole thing gets vacuum packed.

Sides part 1

I had the side panels laser cut out of 1/4" Luan. The laser cutting should give me a perfect fit for all the parts and perfect profile. The cutting was done by http://bclaserworks.com

The pieces were cut in 4'x4' sections because that was the size of the laser table. This means one extra joint in the sides, but I think it will be worth it to get the precision cut pieces. These pictures show the panels and the pieces removed from the panels for the inner right side.

The next step is to glue a wooden frame around the perimeter, cut the 1" foam core, then laminate the inner and outer pieces with the foam.

The Floor

The floor is made of 2" foam with 1/2" plywood laminated on top. GreatStuff (tm) foam was used as the glue. The 2" foam fits down in the frame.

To do the laminating, I need to have everything wrapped in plastic, so I pulled the foam back out, laid plastic over the frame then dropped the foam back in. The plastic will keep the floor from sticking to the frame and will allow me to vacuum pack the whole thing.

Next squirt the GreatStuff on the foam (sorry, no pictures), then the plywood goes down. The perforated vacuum hose goes next, then the plastic is folded over and the seam is taped. Once the vacuum is switched on and the air gets sucked out, air pressure squeezes everything together.

I let the vacuum run for about 6 hours. The can said the foam took 8 hours to cure, but it was bed time and I didn't want the vacuum to run all night. The next day, I stood the frame up, popped the floor out of the frame, removed the plastic, put the floor back in, then drilled the bolt holes through the foam and plywood. I used the pre-drilled holes in the brackets to align the holes.

I now have a rigid, insulated floor. Time to build the walls.

If I had this step to do over, I would have placed a scrap of plywood over the plywood joints and temporarily screwed them together. This would have made it easier to get everything lined up and reduced the chance of things slipping while getting the vacuum pack going. The plywood shifted a little, so I had to trim things once it was all set up.

The Frame

The frame is mostly complete. I still need to touch up some of the welds, and I need to add the hangers for the axle. The frame is designed to be removable, so at this point, I plan to build the body then remove the body to paint both it and the frame. I can weld the axle hangers at that point.

The "tails" in the back provide a steel back to the trailer to minimize the damage should I ever back it into anything. I didn't include a solid back because the kitchen area will be set in from the back of the trailer. Without this, I'd either need a pull-out counter, or you'd have to reach across a ways to get to the counter.

The body will bolt to the frame through the floor. There are brackets at each corner and on the tails for the bolts. The brackets are on the bottom so the bolts will go through the plywood and the foam.

Howard's Hopper

About six months ago, I was tent camping with my wife. I've been thinking for awhile that we might do more camping if we had a trailer. In the campground there was a teardrop as well as a number of pop-ups. We looked at the ones in the campground and when we got home I looked for used pop-ups on Craigslist. After looking about, I decided on a teardrop for the following reasons:

1. Most pop-ups are still tents. Granted, they're nice tents, and they are off the ground, but the roof over the sleeping area is still fabric. The Chalet Alpine pop-ups are a notable exception to this rule, and there were a couple of these in the campground that we visited, but...
2. Pop-ups, even used, can be rather expensive.
3. I wanted something small and light, so I could tow it behind a small car.
4. I thought it would be fun to build one myself.

So, having decided to build a pop-up, I looked around for pop-up designs. There are lots of designs available on-line. You can find some of them available here. But being a doitmyselfer, I decided to invent my own design while I was at it. Here are some initial drawings of my idea.

The frame will be steel. The floor will be 1/2" plywood laminated on top of 2" foam for both stiffness and insulation. The sides will be a lamination of 1/4" plywood on the outside, 1" foam, and 1/8" plywood on the inside. The roof will be a lamination of 1/8" plywood, 1" foam, and 1/8" plywood. I haven't decided what the finish will be. I like the look of wood, but I'm not the best of woodworkers, and paint can hide a multitude of errors. Aluminum also looks nice - it's the "traditional" finish, but I don't know if I want to get than fancy.