I’ve been silent on the Teardrop project for a while. After the mad rush to get it rolling, licensed and to California, it’s mostly been sitting. I’ve been back and forth to Texas to empty and rent our home there, not to mention dealing with other business. With everything going on, it’s been ignored while I work on other projects.

All that has changed because I now have a deadline… Adrian and I are hoping to take it on a Xmas – New Years camping trip this year. That means it’s time to start working through the punch list for real.

Adding Metal Skin

The last week’s activity was all about prepping for and starting to install the metal skin. San Diego has a great local metal supply shop – Industrial Metal Supply that was able to source what I needed (in stock no less) and deliver it. On a side note: they were SUPER PATIENT AND HELPFUL which is not what I expect from industrial material supply places.

The metal skin for this trailer is substantial. If I ever build version 2 I’m going to be more careful of a couple critical dimensions. The trailer sides are just under 5 feet tall, and just under 12 feet long. Luckily, I could get 12′ x 5′ mill finished sheets of aluminum. The thinnest I could get was .063 (1/16 inch). They are heavily than I would have liked, but that is probably for the best.

The roof is more of a problem. The trailer is 63″ wide to accommodate the queen sized mattress. A 12′ x 5′ sheet is 144″ x 60″, which means I can’t use one sheet wrapped from the front bottom to the rear hatch. I have to assemble the roof from smaller sections. If I had built the trailer narrower, I could have used a single 12′ x 5′ sheet as the front and roof. The linear distance is just under 12′ excluding the hatch.

As it stands now, I’m basically using three 4′ wide sections with seams. It isn’t ideal, but it should be fine since there are a couple “natural” seam locations. Strategic trim should handle the rest.

Installing Side One

I jumped right in and installed side one ASAP. I have nowhere to store the huge 12′ x 5′ sections of metal. They are to floppy to stand up and to huge for my garage. The best and safest place for them is on the trailer.

Moving them requires multiple people. Only my wife was available so we made it work with just 2 of us. 3 or 4 people would have been better. As a result, I was mostly scrambling to get the side up and on while the glue was still in it’s open time. I only took pictures at the end.

Choosing a Glue

I’m using outdoor carpet adhesive as my glue. I’ve seen a lot of different approaches including: contact cement, construction adhesive (polyurethane based), silicone (i.e. caulk) and mechanical fasteners.

Ultimately I decided to go with carpet adhesive because it has a reasonable open time (30 minutes to an hour),  is NOT instant bound and should not require any mechanical fasteners once dried. It should also remain flexible when fully cured allowing for the different rates of expansion between the aluminum and the wood.

Contact cement is great, but the idea of trying to position this huge sheet of aluminum without touching the trailer in the wrong spot was terrifying. Silicone caulk isn’t really an adhesive and I don’t know that I would trust it without mechanical fasteners. Construction adhesive might have worked, but the usability is low (the calk gun tubes aren’t quick for spreading over large areas) if I want 100% coverage. It is also way more expensive per sqft.

The Mad Procedure

Here is the basic process I used for side 1:

1. Clean the aluminum so it is oil free. I used some brake parts cleaner to do this.
2. Drill the hole for the porch light wiring.
3. Clean the side of the trailer and make sure it is smooth (i.e. sand and bumps or glue that was standing proud).
4. Place a ledger board under the edge of the trailer to support the bottom of the aluminum while it is clamped.
5. Spread the adhesive using a fine toothed trowel. The clock is now running!
6. Place the aluminum.
7. Clamp.
8. Wait and hope…

I went into this not knowing exactly what to expect and I had to quickly improvise clamping. The other side should go much smoother with some better prep and clamping plans.

Clamping

I wasn’t sure how much clamping would be needed. The answer was a lot more than I thought… Life would have been a lot easier if I could have set the trailer on its side. But, physics being what they are, that wasn’t an option.

I ended up pressing a full sheet of plywood along the front part of the wall. This wasn’t as helpful as it might seem without other clamping. Plywood isn’t perfectly flat and neither is the wall. It provided no pressure alone. Other clamping was required to press it into the wall everywhere.

The bottom edge is clamped against the frame rail firmly using standard clamps and boards. That was easy.

The rear hatch area was clamped buy drilling large holes in the aluminum in the waste area and clamping through it against a large board and the inside wall.

The top and front were a bigger problem. I ended up attacking it a couple of ways. For the other side, this is where I’m going to do things very different.

Lets start with what worked well, which I didn’t think of until the very end. I drilled a whole in the middle of the door opening, then used a 2×4 on both sides of the trailer and a ratchet strap to pull things snug. Next time, I’m going to use 3 of these, one high, middle and low each since it worked really well.

I’m also going to get some 8′ pipes for my pipe clamps so I can clamp the front edge all the way across the trailer instead of the strap and shim arrangement I used this time.

Failed Clamping Strategies…

I initially tried wedging 2×4’s against the garage wall to press the plywood into the aluminum and provide camping force. Unfortunately, the trailer is mobile. I almost pushed it off the jack-stands. Not doing that again…

To try to provide some clamping around the middle of the trailer I initially drilled some more holes along the top edge of the waste and ran straps over the trailer to the far frame rail. This provides limited clamping without a lot of blocking under the straps. Once the straps were in and snug, I wedged blocking under them. For wall 2, I’m going to pre-cut some wedges in case I need to do something similar.

I also had to install some pan head screws along the front top edge. The small holes above the screws are locating holes drilled from the reverse side to help with placement. I will remove the screws once the glue is dried. The holes should be under the edge trim and invisible. Regardless, I would rather not have done that. Longer pipe clamps will fix that problem next time.

Tl;DR – For Wall Two

For the other wall I will:

• Start with the door to door strap+2×4 clamping, one at the top, middle and bottom,
• Pre-drill the large holes for clamps along the top edge to save time,
•  Have 8′ pipe clamps available.
• Cut wedges for general use.

I had a lot of scrap wood lying around as well as a half dozen 2x4s and a couple of 2x6s which was a life saver. I also have a huge number of webbing straps, and lots of other small clamps. All that was good. A little more prep on the aluminum (the big holes for clamps) and a slightly different plan and things will go much smoother.