A Brit builds a cedar stripped teardrop

[MikeG2]

I joined here many years ago when I first thought about building a teardrop. I have finally started. I am an architect nearing retirement, and a lifelong woodworker.

In fact, I have nearly finished building the teardrop, but haven't posted here about it until now. I am going to post the whole build thread as fast as I can...but it's not real time. This is what I am planning on building:

This isn't met with unbridled enthusiasm by my wife, but she understands that the alternative was a boat. She used up her veto on that idea, so, a teardrop it is..........This is the lesser of two evils for her, and our motivation is that we can use it to cycle, walk and paddle in new areas at short notice.

The strategy is to build everything from scratch, including the chassis......but the chassis will be delegated to a local fabricator. Everything else will be by me. One of the deeply frustrating things in the design process has been the lack of accurate information. I have been ordering stuff "blind". There are a couple of critical dimensions I need for the chassis design, and one of those was the space needed for the bikes to sit on the tongue. So, I bought a couple of roofrack bike stands from Facebook Market-place, and rigged up something temporary to check on the minimum spacing:

A friend printed me some plastic knobs for those stands. I took the necessary measurements and adjusted the tongue length to suit. The far bigger frustration was not knowing the ride height of the chassis with my chosen wheels, tyres and suspension units. In the end, I just had to buy the stuff and measure it for myself.

So, decision one.......15" wheels. I came to this not only from looking at my drawing, but also from measuring a friend's teardrop which I've had here for a week or two for some repairs and alterations. After liasing carefully with the company supplying all the trailer bits-and-pieces (suspension units, hitch, jockey wheel, corner stands, lights etc), this package turned up:

.........and was then fitted with a pair of 215/65 R15s (it turns out that's a standard size for vans such as Transits, so these are 8 ply tyres):

I then went to order all the stuff I just mentioned, and found out that the only hubs which would fit my wheels either had to be specially made, or had to be braked, which I don't need. For the sake of speed, I opted for the braked hubs, but empty of all brake components. A package of goodies turned up a couple of weeks later:

The guy at the trailer parts supplier had estimated the clearance between the inside wall of a tyre to the plate of the suspension unit at 35mm, and I could now measure to find out the accurate figure. Luckily, he was close, as it came to 39 or 40mm. This is a critical figure because the side walls of my caravan come down outside the chassis, and I need to organise for there to be enough clearance.

Now, to measure the chassis ride-height, I decided on an experiment. I decided to bolt the suspension units and wheels onto a board, and load it up. It was actually pretty straight-forward. I coach-screwed the units onto a pair of scaffold boards:

At this point I took a baseline measurement (mark on a stick). I then loaded up the planks with 50 bricks:

The design weight of my trailer is 650kgs, so, after I weighed a brick (I actually weighed 5 different bricks and took the average) I was able to do some calculations.

I've hit the image limit here, and this is an image-heavy thread. So, I'll be back in a minute.

 

[MikeG2]

I measured the deflection:

I was able to do some simple arithmatic and come up an estimate of the chassis height under a full load:

The design height of the teardrop is really important to me. I've seen some US builds where the kitchen worktop is near chest level. My wife is 5'-2", so I'm aiming for a worktop at an orthodox 900mm above ground level.....and that is determined by how high the chassis sits under a load I can only estimate. Hence the experiment. I can now complete my drawings for the fabricator, relatively confident in the ride height of the finished teardrop.

I won't be producing the detailed drawings for this build. There are quite a number of innovations in my design which will just be stolen/ copied immediately by others. However, I can let you see a plan of the 2.7 x 1.5m chassis:

You can see the bike rack on the front, and the framing for a "well" above the axle location. This is for a water tank and battery compartment. The big innovation in that drawing, though, are the plates with multiple holes, giving 4 locations for the independant suspension units. As I have never built one of these campers before, I can't be certain where the balance point should ideally be. The front compartment is just a bed, so is very light. The rear holds a kitchen, stacked with fridge, cooker, food, cooking stuff etc, so is comparatively heavy despite being small. Having the ability to move the axles backwards or forwards, in addition to being able to move the battery/ ies in the big well, gives me the best possible chance of getting this thing properly balanced.

I sent the drawing off to the fabricator, and began work on the walls.

I picked up a couple of sheets of 3mm hardboard from which to make a template of the inner skin. Note this, because this is a fundamental difference from any teardrop you can find on Youtube, who all make the OUTER shape first. I think this leads to some very poor detailing. My shape is therefore going to be the shape of the interior. Unusually, again, It's bigger than a single sheet of ply:

I spent a couple of hours on my hands and knees, doing a form of lofting. The join is like this because it will be hidden behind the partition between the sleeping area and the galley (kitchen):

I had to put some off-cuts under the main sheets because it was too thin for the nails to get enough grip to resist the forces of a spline. Unfortunately, I couldn't find a scrap long enough to make a spline long enough to do the whole curve in one go:

I had to keep reminding myself that reproducing exactly what I had drawn would be nice, but not critical. More important was making a fair curve. Luckily, my drawing was pretty much spot on. I cut it out mainly with a hand-saw, but also using a jigsaw.

Note the strategic deployment of the bin! This board is very floppy. It's also pretty weak, so I couldn't do the entire door cut-out, and had to leave a reinforcing strip connecting the bottom:

A couple of things to note. Firstly, the door is huge. It's 900mm wide. Believe it or not, I measured how I get into bed, and as I am making the door and not relying on what is commercially available, I've ended up with something I'll be able to easily climb in to in the dark without folding myself up too much. Secondly, the bottom of this template sits quite a long way above the chassis and the floor of the finished camper. You'll see a very unorthodox build-up below the bottom edge, mainly to gain height inside and prevent claustrophobia without resorting to over-sized sheets of ply, which are extortionate.

This is a template, and I'll use a router with a bearing guided trimming cutter to cut out the two sides

It's worth saying at this point that I am a traditional furniture maker, and will be building the entire teardrop using traditional joinery (ie half-lap joints, mortice and tenon joints, bridle joints, and so on. There are going to no butt joints anywhere on the entire job, and, my pet hate, the roof will sit on something, rather than being fixed through the walls into end-grain.

 

[gearsoup]

Oh this looks like it's going to be interesting, tagged to follow along

 

[MikeG2]

I bought some beautiful pieces of Douglas fir for the framing, and some western red cedar for the cladding:

I have a 30sq. metre workshop, and typically for this country, don't have a table saw. All my stock preparation is by bandsaw and planer thicknesser (British terms will be used throughout!! ).

Whilst awaiting the arrival of the chassis, I took the opportunity to do stock preparation. Preparing long bits of wood in my workshop isn't completely straightforward. I decided to start with the framing material, which is Douglas fir (6x2). I opened my hatch:

.....and put a face and edge on all of the boards using my planer:

Unfortunately, with a short infeed table, this does nothing to straighten or flatten, so I set about doing that by hand. I use a long straight edge of aluminium, which I rub backwards and forward on the wood. This leaves a grey smudge from the oxidation on the high spots:

....which are then easy to plane off by hand:

However, the boards are way longer than my bench, and this was just going to be so slow and cumbersome. I came up with a new plan to get a reference edge. I would rip a straight edge through the middle of the boards with a circular saw:

After passing this over the planer I had a decent edge from which to rip strips on the bandsaw:

It took careful positioning of the bandsaw (my only moveable piece of machinery), to be able to fit the wood through the machine. I ripped it all into strips, and then carefully set up the thicknesser to produce the exact same thickness (25mm....not an inch) as the insulation boards I'll be using:

 

[MikeG2]

The roof members will be used on edge, rather than flat, and the couple of pieces which came up a bit thinner than I'd hoped were marked up for use in the roof:

I need a few 4x1s, as well as all those 2x1s, so I edge-joined some 2x1s:

With the thicknesser set I then brought everything to its final thickness:

That's the framing stock prepared. Now for the Cedar strips for the outer skin. I had selected some wonderful straight quarter-sawn stock at the woodyard:

This is all going to be ripped down into strips finishing about 22mm x 6mm. To get theose to end up quarter sawn, I needed to first cut into 23/ 24mm strip parallel with the end grain, but before doing that I needed reference face and edges. Quickly through the planer on adjoining faces:

Then, because there is no chance of squaring this up through my small machine, I brought everything square with a hand-plane:

Finally, I could start bandsawing. Saw-plane-saw-plane-saw-plane.........

...............would be the story of the next 2 or 3 days. I don't use my hatch often, but when I need it it's invaluable:

 

[MikeG2]

Eventually, I had a pile of 24-ishmm wide planks, planed all round (bar one edge):

In addition to having western red cedar in the outer skin, I want to have some contrasting strips. Up in one of my wood-stores (the workshop loft) I knew I had some ash:

I cleaned it up and ripped and planed it to the same thickness as the cedar:

Saw-plane-saw-plane-saw..........ad nauseum. It was really nice to see the contrasting colours emerge. Cedar is soft and light, but can be beautiful.

In the middle of all that work, my plywood arrived. It is a mixture of 3mm, 6mm, and 12mm poplar ply (plus some phenolic ply for the floors). I was surprised by how pale it was, and by how light it was, and my first impression is that it looks decent quality (flat, true, and lacking in visible voids):

Eventually, days later, I had a pile of strips, and lots of bags of shavings:

Just as an experiment, and to show you the wall build-up, I prepared some ply, some Celotex, and some cedar:

 

[MikeG2]

I glued one of the wall mock-up bundles together using PU:

.......and when it had dried overnight did an experiment to show the difference between unglued and glued panels. I hung weights on the glued and the un-glued wall sections:

The far one is glued, and the near one isn't.

That's the reason I will be using PU glue on this build, and why the insulation will be glued in place both sides. I've never seen anyone do that, in the hundreds of videos on the subject on Youtube.

 

[S. Heisley]

Thank you for posting all the pictures and descriptions of what you are doing. This is wonderful! I look forward to watching your build.

 

[Tony Latham]

This is a great build thread.

Of note, have you figured out if your vehicle will engage the bikes in a turn while backing?

I mounted this removable bike rack over the tongue box to get the bikes away from the truck fenders.

It folds down so we can access the tongue box.

I've got a bike rack build thread on here somewhere, if you're interested.

But PLEASE keep the photos coming.

Tony

 

[MikeG2]

This is a great build thread.

Of note, have you figured out if your vehicle will engage the bikes in a turn while backing?

I mounted this removable bike rack over the tongue box to get the bikes away from the truck fenders.

It folds down so we can access the tongue box.

I've got a bike rack build thread on here somewhere, if you're interested.

But PLEASE keep the photos coming.

Tony

Unfortunately, your images show as "content not available in your region".

But yes, I considered the reversing/ turning angles:

It's obviously something I've got to watch, but it is only the height of the handlebar of the forwardmost bike I've got to watch, otherwise there is no contact possible at any angle.

 

[MikeG2]

Time to do some proper woodwork.

I had never seen a teardrop in my entire life until a few weeks before. They're a real rarity here in the UK. But someone on Facebook had asked if there was anyone who could do some repairs, and I volunteered, mainly to see how they're made commercially. It was an absolute disaster, and very revealing. The frame had butt-and-staple joints. That's not my way. I am going to make this as though it were a boat, or a piece of furniture. I started by cutting up all the Douglas fir stock and laying it against the pattern:

I do stuff by hand where I can, of course:

I've a frame drawing I won't bore you with showing the location of all the timber in the walls. Much of the location boils down to where I'll need to fix into the walls, so it's been carefully thought through. The most solid point of the frame is the door surround. With all those loose pieces following the curve of the roof, I thought I would start construction with something solid and fixed, to which I could then attach other components. So I began with the door frames. Marking out and joints are as per usual: knife, square, chisel, saw.......but then I used a router (screaming monster) rather than a router (plane) to get the depth of the half-laps right:

Shoulders:

I quickly hacked off the bulk of the waste without much marking:

Screaming monster (with a bearing guided trim cutter):

The housings were again marked with a knife, then sawn, chiseled and routed. I'll see if I can remember why I chose to do blind joints...........

After a quick clean up in the corners of the housings it was time to glue. I have bought myself a new toy for this job, because of the cedar strips on the outside. I thought that rather than clamp I would try the air pinner out:

I made two of those, as I did of everything else. There are a lot of lap joints in my immediate future.

 

[MikeG2]

Here's the first of the door frames:

The doors are going to have radiused corners. To achieve that, I needed to add something into each of the corners of the door frames. In preparation, I made a cardboard template, and glued up some scrap Douglas fir:

I thought I'd got it right, but I could only fit 7 of the eight I needed:

So, I cut off four of them so that I could get on, and glued on another offcut. That will be ready tomorrow. Here are the shapes cut out:

It's worth saying at this point that everything other than the joints are being made slightly over-sized at the moment. When the frame is complete and the ply inner skin fixed in place, I'll place the big template over the whole thing and go around with a flush trim cutter in the router, and bring everything to it's final size. So, these little corner pieces just had their sides squared up on the linisher (well, you know....belt sander-in-a-jig). The curve will be done when the whole wall is trimmed.

I pared for the corner pieces:

And glued them in place:

 

[MikeG2]

I half-lapped various pieces of the out frame together, starting at the front where it's straight:

This enabled me to mark carefully for the sockets for the half laps securing the door frame into position:

With a dab of helt-melt glue under the bottom ends of the doorframe, I finally had some solidity about the whole frame, and something to reference all the other pieces from.

I don't want to bore you with endless photos of half-lap joints, so here is one group showing how I am doing them all:

I then worked my way aft, marking and cutting, and gluing up as I went. I have to say the little second-fix air pinner is brilliant. It's going to save a lot of time and clamping later on (but it's not like I'm in any particular sort of rush).

I must say I am thoroughly enjoying myself.

 

[MikeG2]

I worked my way around from front to aft doing all the joints in sequence, and eventually I had all the top done, all the verticals done, and the intermediate horizontal timbers which are for fixings for cupboards etc.

As you can see in the above photo, the next thing was to fit a horizontal along the bottom of the frames. More half-laps:

That was soon glued and pinned:

Those joints are blind, deliberately, because I don't want end grain exposed externally, and the under-edge of the frame is going to be exposed to water splashing up from the road. Well, almost. It will have a cover strip over it, fibreglassed, but should any water penetrate I wouldn't want it to find end-grain. It was a big moment detaching the frame from the pattern, involving a few goes through a mental checklist.

Time for some ply. As I said, I have bought poplar ply for this job, and I have been very impressed. However, there are some quirks. Firstly, it is 6.2mm x 1220 x 2500 in size. So, 1/4" x 4 feet by 2.5 meters......a weird (and typically British) mix of metric and imperial. Secondly, it's not square!

Ho hum. That just means careful checking on the bits where right angles are required. I clamped 2 sheets of 6mm together, and clamped the pattern on top:

After marking out, I found my most rarely used tool, the jigsaw, and cut out roughly:

The off cuts show the quality of the ply:

Yeah, it's not prime birch ply, but it weighs about half as much as birch, and is definitely not too shabby. I then cut out the back ends.

Next, I did some very careful setting out, with the straight edge at the bottom being the reference from which everything is set out. I then glued and pinned it in place:

 

[Tony Latham]

Unfortunately, your images show as "content not available in your region".

Weird.

Your brain has been cranking on this project.



Tony

 

[MikeG2]

Weird.

I suspect your images may be being hosted on Imgur. They have stopped allowing access to their services in the UK.

 

[MikeG2]

But Mike, I hear you all cry, the ply doesn't reach the bottom of the frame!

Patience. All will become clear. Once the glue was dry, I went around with a flush trimmer, and produced the final shape for most of the wall:

My half-laps had worked OK:

The trimming went pretty well, but it's not my favourite thing. One slip of the screaming monster and you ruin both your template and the workpiece. I stood it out of the way to get on with the next thing:

I took some 150x19 nominal PAR (145 x 14) and thicknessed it down to 12mm thick. Out came the router again, this time with a winged cutter to do a rebate on the edge of the boards. Honestly, I hate the router, and have used it more in the last week than in the whole of the last year:

That rebate is the same depth as the ply:

Given the option of getting another cutter out for the router to do a round-over, or having a few peaceful minutes with a block plane, I set the bloody thing aside and walked the length of the boards a few times:

That rebate cover the bottom edge of the ply:

Before fixing it in place, I made very certain that the bottom edge was straight:

 

[MikeG2]

With the board clamped in it's final position, I took an offcut of the framing material, and marked out for the bottom edge of a joint on each of the vertical frame members:

The router didn't get to rest for too long. I fitted a guided trimming cutter, again, using the edge of the PAR as a guide, I formed the top edge of the joints:

With a tenon saw I then cut the other edge (after the board was removed), as well as cutting a couple of vertical cuts on the same:

This was as a result of being awake at 3.00 last night. You have to think about something.

The piece which will fit in that housing is going to be doing a lot of work, structurally, so removing any chance of it twisting or otherwise moving just seemed like a good idea. Next up, I fitted the edge of that board (4x1) into the housing, and marked it up:

Before housing out to those lines:

Two 9mm housings gave me 18mm of lap, and a really strong junction:

After rough-cutting the bottom of the door opening in the pine, it was time to glue that lot up:

I decided to use the 502 (non PU) for the top edge, where the board is rebated over the bottom edge of the ply, because I didn't want to be dealing with a heap of glue oozing out of the joint, which may or may not be on show in the finished item. The glue up went well:

I went off and did other things for a couple of hours, then came back and de-clamped. I pinned on the template for the lower edge of the door, and trimmed the PAR to shape. It MOSTLY went well:

 

[MikeG2]

One bit will need some hand-work:

So, barring a couple of small jobs, that's the woodwork of one side finished for now:

Here's a fun little detail, which you'll have to remember for later, when this lot is fixed to the chassis:

Talking of the chassis, it's coming soon. Exciting!

 

[MikeG2]

I sneaked an hour or so in the workshop, and got it insulated:

The fly battens were to prevent the expanding foam of the PU glue from pushing the insulation upwards. It's critical that it stays flush with the timberwork. In some areas I did a tight fit, much more often, I left gaps to fill with foam: