G&M's 'Drop

[GarthB]

Hey Everyone,

My name is Garth and my wife and I have embarked on our first teardrop adventure - the build. I am a Civil Engineer by day and my wife is a nurse by night. We both love the outdoors and have been eyeing teardrops for a few months. The astronomical prices of factory teardrops were out of the question for us and I love to build things during my free time, so a build seemed like a good fit. However, my biggest apprehension was sourcing all of the material during a time when material prices are through the roof and things are hard to find.

One day while surfing Craigslist, I found a heap of teardrop parts that a gentleman was selling. He'd started a build but later decided to pursue other hobbies. The highlights of the heap included a 5x10 trailer built by a local trailer shop, two doors, aluminum sheets, trim, a hurricane hinge, inverter, lights, outlets, and a floor. After a little wheeling and dealing, I picked it all up for a steal of a deal. The build had begun.



The first thing I did was strip the trailer of the structure that the original owner had built. I wasn't a fan of the design philosophy that he had.



Next, I removed the floor (3/4" birch). The top side was polyurethaned and the underside was covered in roofing tar. I plan to use this, unless anyone has any roofing tar horror stories to share.



With the floor off, this allowed me to inspect the trailer wiring. I have never seen a factory built trailer with a wiring job built to last, and this was no exception. I went through all of the wiring and waterproofed all of the connections with liquid electrical tape.

With a clean slate to build off of, I turned my attention to designing. With my day job being as busy for me as it is right now, engineering both during the day and during the night really didn't sound all that appealing to me. That was around the time I stumbled across this forum. A few, very respectable, names seemed to repeatedly jump out with helpful replies under every thread that I read. I wound up reading Tony's build journal and his build strategy impressed me a lot. I liked the majority of the features that his teardrop had and decided that I would base my build off of his tried and true design, rather than spending precious shop time designing my own. A few tweaks will be made to suit our style and desires, but my wife and I both think that this basis of design will suit our needs well. Thank you Tony! Your book is well written. Our goal is to have this thing ready to camp in by mid July so that we still have a good chunk of Northern Michigan summer to enjoy it.

I started by making the template with some leftover 1/4" plywood from a different project:



Next came the skeletons. We decided to use 3/4" marine grade ply for these. I used a top bearing, flush cut router bit for the outside edges and the door cutouts. Both skeleton walls were screwed together along with the template on top.


The insulation voids, roof blocking, and floor were cut out while the skeletons were screwed together as well. I used a high quality up-cut jigsaw blade for the voids and a 1/4" spiral upcut bit with an offset router guide for both the roof blocking and the floor.



All the while, as I was working during these previous steps, I searched high and low for 1/8" birch plywood. The stuff is harder to find than just about anything right now. I called every lumber yard and specialty hardwood supplier that I could find a phone number for across multiple states and nobody could get it until mid-June. I was feeling pretty defeated. Then one day, I was on the phone with Frank Bear of Vintage Technologies to order a roof vent fan. I happened to mention that I was having a hard time finding Baltic Birch and he offered to let me buy some, if I was willing to make the 4 hour drive to his place. Having no other option, my wife and I took him up on his offer and made a road trip out of it.


At this point, we are in the process of gluing up the prized 1/8" birch to the interior sides of the skeletons, and as I was writing this post, I realized that I made my first (likely of many) unfortunate mistakes. Since I am using 1/8" birch on the interior sides of the walls and 1/4" birch on the outsides of the walls, I should have remembered to glue the 1/8" so that the two walls were opposites of each other. Instead, I completely forgot and now both walls have 1/8" glued on the same side. Luckily, I purchased 4 more sheets of 1/8" than I actually needed. As a fix, I will glue up one of the walls so that it now will have 1/8" on both sides. Both sides of this wall will be flush cut to the skeleton and have the dados cut. I will then proceed with gluing 1/4" with the overhangs for the floor and roof to the exterior sides of each wall as originally planned. All said and done, one wall will be 1/8" thicker than the other, but thankfully it is a mistake that I can recover from. When I first realized I did this, I thought I was going to need to rebuild the whole wall.

Here's a picture of the glue-up:



Thanks everyone in advance for the thoughtful replies and insight! My wife and I are excited to make this build a reality.

[QueticoBill]

I may be only one but can't see photos, just the image icon. We love photos!

[western traveler]

Looking forward to following your build.
The photos are viewable now.

[noseoil]

Tony's book is really good for a guide & having correct information on a build. It helps to have a well organized set of instructions to use as a reference when things are going on in the shop. A bit of browsing at night after the work, helps keep perspective & ideas in order!

The 1/8" skins are fine for both the inside & outside of the walls. That's what we used & our trailer is still going strong after a few years & over 20,000 miles of travels. The 1/4" outside ply is actually more than you need structurally, it adds weight & doesn't contribute to the box's strength (just my opinion, I'm not an engineer). If you run the numbers on them, I think you'll see that the forces are redirected within the 3/4" skeleton by the 1/8", just as well as the 1/4" skins, since the redistribution is more a function of the inside & outside combined with the sandwich, than the actual skin's thickness if fasteners are done well (glue, weights & small pins for alignment).

We used 1/8" skins for our floor system both top & bottom, with a 3/4" thick poplar frame for hard points. It's held up very well so far. 3/4" insulation supports the floor inset into the voids. I did "cheat" & double in the galley area to help hold the battery box weight (65# AGM deep cycle), along with an extra piece of 1/4" laid on top where the "backside" drops onto the mattress at the door at night.

Looks like a good start on the build, just remember to have the "moaning chair" handy when those little mistakes sneak up on you & bite your backside once in a while.

[swoody126]

GarthB, NICE BEGINNING !

you have discovered and bought into something many are not willing to

driving several hours to secure the right stuff

all too often folks end up scrimping on material quality for the sake of convenience

FOLLOWING

sw

[working on it]

...
you have discovered and bought into something many are not willing to

driving several hours to secure the right stuff

all too often folks end up scrimping on material quality for the sake of convenience....

* Trailer building: an idea becomes a plan, then enhanced by enthusiasm and desire, followed with the obsession and conviction/dedication to reach a satisfactory conclusion, no matter what. At least it was that way for my build, where I made about 5000 miles of trips to my remote build site, and further travel while seeking parts, and untold hours spent concocting new modifications to what I'd already planned or built. 22 months from start to finish (first iteration) of the build.

* While my build's true cost was a secret from the wife (she'd allowed a $500 max for the project, after my dragracing budget had been unregulated before), I bought what I felt would be necessary for durability and strength, no matter the cost, and simply disposed of receipts (all cash, no credit used). Eventually, at home in the garage, the trailer was evidence of $500+++ spent, and final purchases (A/C, windows, mattress, etc) were made in plain sight, with her grudging approval.

* You're lucky to have your wife excited about your trailer build...mine wasn't, hence the remote building site 50+ miles from home. Actually, the trailer was designed for her use alone, not mine, and only became mine when she had a claustrophobic episode while testing it in the garage. She never used it, nor ever camped again, so it is mine. Good luck with your adventures (building and camping, both)!

[GarthB]

Tony's book is really good for a guide & having correct information on a build. It helps to have a well organized set of instructions to use as a reference when things are going on in the shop. A bit of browsing at night after the work, helps keep perspective & ideas in order!

The 1/8" skins are fine for both the inside & outside of the walls. That's what we used & our trailer is still going strong after a few years & over 20,000 miles of travels. The 1/4" outside ply is actually more than you need structurally, it adds weight & doesn't contribute to the box's strength (just my opinion, I'm not an engineer). If you run the numbers on them, I think you'll see that the forces are redirected within the 3/4" skeleton by the 1/8", just as well as the 1/4" skins, since the redistribution is more a function of the inside & outside combined with the sandwich, than the actual skin's thickness if fasteners are done well (glue, weights & small pins for alignment).

We used 1/8" skins for our floor system both top & bottom, with a 3/4" thick poplar frame for hard points. It's held up very well so far. 3/4" insulation supports the floor inset into the voids. I did "cheat" & double in the galley area to help hold the battery box weight (65# AGM deep cycle), along with an extra piece of 1/4" laid on top where the "backside" drops onto the mattress at the door at night.

Looks like a good start on the build, just remember to have the "moaning chair" handy when those little mistakes sneak up on you & bite your backside once in a while.

Thank you to everyone for the replies thus far. In regards to the 1/8" exterior walls, I would probably agree, especially since we will be fiberglassing the walls with 4oz cloth. Unfortunately though, I pretrimmed the 1/8" plywood closer to the bottom edge of the skeleton than I need for the overhang of my exterior layer. Both 1/8" layers and the 3/4" skeleton layer will have to sit on top of the floor.

As for the floor, I am considering just adding a layer of 1/2" ply to the 3/4" that I already have in order to achieve the desired 1-1/4" thickness. I'm still debating this though, since it would likely require me to sand off all of the polyurethane that the previous owner applied in order for the glue to bond properly. I could just use screws, but that would leave more opportunity for water entrapment between layers.

[GarthB]

With 1/8" baltic glued to both walls, I flush cut all the edges and dados. While I was doing this, my wife cut 3/4" foam for all of the voids and we got them set. Now, just waiting on the wall with the additional layer of 1/8" to dry before we can move on to the 1/4" exterior skins.

[noseoil]

Don't forget the wire runs (reading lamps, switches, charging ports, running lights, etc.), just sayin'...

[GarthB]

Don't forget the wire runs (reading lamps, switches, charging ports, running lights, etc.), just sayin'...

Every helpful reminder is appreciated, no matter how obvious it may seem! We'll be installing porch lights and reading lights on the walls. For the wiring, I used a 1/4" router bit and cut 3/16" deep channels in the skeleton for the wires to run. They'll tie in to the rest of the wiring inside the roof.

[GarthB]

Finally seeing the light at the end of the wall construction tunnel, even though cutting out the hatch is still standing between us and the finish line. I cut 1/4" birch ply using the template for the exterior sides of both walls. Prior to glue up, I used a 1/4" router bit to make channels for the wiring for the porch lights and the interior reading lights. Using blocking on the bottom and leading edges to properly align the exterior skin worked well and made the glue-up easy.

While the glue was drying for the first wall, my wife and I daydreamed for a little while about finally getting to mount them on the trailer.



Before the floor and walls get mounted, I'll need to move the axle back 4" or so to account for the door clearing the fender.

Once the first wall was dry, we repeated the process with the second wall. It felt good to finally have the full-wall glue-ups behind us. Additional layers will still be added in the galley, but at least those won't require a second set of hands to complete. Here is a photo of the first wall completed, prior to cutting out the door:



We hope to lay fiberglass this coming weekend. The weather is forecasted to be around 50F all weekend and we will be laying it in an unheated garage, so I need to first make sure that it will be warm enough to cure the epoxy (Raka) in a reasonable amount of time. I'm still debating whether or not to wet out the wood with epoxy prior to laying the fiberglass. I'm leaning towards the idea that the cloth will be easier to align on a dry surface.

[GarthB]

Yesterday was a good day of teardrop building. The temperature was around 50F all day so we ended up taking over my parent's heated garage in order to get the walls fiberglassed. We opted for Raka's medium viscosity resin with the non-blushing hardener and 4oz standard woven fiberglass cloth. Prior to glassing, we cleaned up all of the edges of the walls and sanded any rough spots on the exterior skin. Thankfully, we had room to work on both walls at the same time in their garage, so we were able to work pretty efficiently.

We both really enjoyed this step. I had previously worked on a deep-pour epoxy project, but aside from that, neither of us had any epoxy or fiberglass experience. A couple "how-to" youtube videos steered us in the right direction. We look forward to doing the roof and hatch.





We ended up doing two coats of epoxy on each wall, spaced about 3 hours apart. The first coat went smoothly and we had no issues getting the fiberglass wetted out and any air pockets removed. A significant amount of this coat was absorbed into the plywood and we could feel the bumpiness of the fiberglass weave when we ran a scraper across the surface at the 3 hour mark. It had tacked up well, so that was when we completed our second coat.

The second coat left the walls feeling glossy smooth after 5 or 6 hours of cure time. There were still a couple small areas where we could feel minor bumpiness, but in my mind, not enough to justify a third coat. If it is still noticeable after we prime it, we will use some thickened epoxy to take care of it.

Next, we will be finishing the floor. I plan to add a half inch of marine grade plywood to the 3/4" floor that we already have. We'll join the two layers with some construction adhesive and screws. It'll be a very heavy end product, but weight isn't a major concern for us and it beats starting the floor from scratch and having to buy even more plywood.

Another issue that I am currently working through is in relation to the trailer. When we set our walls on it the other day, I noticed both ends had about 3/8" of a gap between the bottom of the wall and the top of the trailer frame. Both sides of the trailer have a slight positive camber bow. My best guess is that when the axle was welded on, they dumped a little too much heat on it all at once rather than staggering it out. I've debated trying to straighten the trailer, but I don't like any of the options for doing so. Instead, I think I will shim the undersides of the floor on either end with 2" aluminum flat bar stock. I won't have to worry about the aluminum rotting and I can bolt right through it when I fasten the floor to the frame.

Because of the bow in the frame, I am going to try to avoid moving the axle back. I don't want to make the curve even worse by adding more heat. We'll see how it all works out once we get some fenders and mock them up with the door.

Any creative ideas that I may not have considered would be appreciated. Thanks!

[Bezoar]

Looking good - you have made nice progress. I look forward to seeing what you do in the coming weeks!

[tony.latham]

Thank you Tony! Your book is well written.

Thanks a gazillion for saying that. It was a job to write.

Tony

[swoody126]

GB, pox is not compatible when applied over primer

the subsequent issues will knot be fun to deal with

any poxifying kneads to be done all at the same time BEFORE any primer is applied uness you intend to use primer compatable fairing materials then on to painting

if when sanding you begin to get a whitish cloth pattern you need another coat of pox to maintain the sealing effect and end up w/ a smooth surface

BON CHANCE

sw