Dometic Waeco CRX-50 Fridge

This seems to be a pretty popular fridge for conversions. It’s a simple compressor fridge, not a 3-way fridge that can also be powered by gas, so it works much like a fridge you’d have in a house – only it’s 12V, instead of 240/120V.

It’s  basic, but it does have a nifty removable ice-box, so you can take it out and give yourself more room for food, or put it in, and make ice for cold drinks or freeze some food for a short while.

12V fridges are stupidly expensive. I don’t know why, given that technically, it’s not much different to a mains-powered fridge 4 times the size and half the cost. I guess maybe it’s about economies of scale.

Anyway, it seems to work OK so far, though I can’t say we’ve stress-tested it. It’s quiet, and hasn’t woken us at night when we’ve been sleeping in the van in moderate temperatures.

£500 from Rainbow Conversions.

2017-10-19: Overhead shelf in the cab

One of the first jobs we did after we bought the van was to remove the bulkhead. We toyed with the idea of joining the cab area to the back of the van by installing swivel seats, but that’s an expensive conversion, and we liked the idea of having what amounts to a separate room in the cab. Our current plan is to have a ‘soft divide’ – likely some kind of insulating curtain, that we can draw across behind the seats, and otherwise leave the cab pretty much standard.

However, there’s a lot of vertical space above the seats that we wanted to make use of, so we fitted a shelf, faced with a wall at the back that forms a partial bulkhead above our heads.

Shelf as seen from the back of the van, with stuff holes for duvets and pillows

The shelf is made from 9mm hardwood ply, and it’s supported at the front and sides on oak battens, which are bolted onto existing attachment points on the cab body.

We used oak because these supporting battens have to take a significant weight, and softwood wouldn’t be up to the task. Also, we knew the frame would be visible, so we wanted something that looked good. Fortunately, the particular plywood we’re using here, while not the high-grade birch ply, does have one nice face, which matches the oak quite well.

Oak support frame underneath the shelf

The shelf is supported by the back by the partial bulkhead, made of 12mm birch ply, which itself hangs from bolts rivnutted to the frame of the van.

We intend to use this area to stuff in bedding when our bed is not in use, so the large cavernous space is idea. We don’t need to worry about things rolling about, and all we had to do to provide access was cut a couple of large stuff holes, with rounded edges (using a roundover bit on the router).

On the passenger side, we also mounted our MT-50 solar controller monitor, which gives us some live info on the state of the battery, power draw, and the performance of the panels.

Vega LED ceiling lights

We’ve got 4 of these mounted along the centreline of the roof, each controlled with its own switch (as well as a master switch for the whole ceiling light circuit).

They’re wired up, but hanging loose at the moment, as we don’t have the roof cladding in, but they look simple enough to fit, just using a silicon or rubber back section to provide a friction fit in the panel. Nice quality.

£13 each from 12V Planet.

Comet submersible water pump

This is the lowest flow rate water pump we could find, but still claims to be 8-10 litres per minute.

We don’t know exactly how water is going to work in the van yet – how much we’ll use stored water on tap. But we expect it to be minimal, and as the flow rate from these switched pumps can’t be adjusted, we want to use as little as possible at a time.

Even with this pump we could empty a 25 litre water container in 2–3 minutes.

So we’ll see how it goes. We might end up swapping it for a manual pump if this is overkill.

£12 from Rainbow Conversions

2017-10-12: Insulation woes

Fortunately, the fine particulates in this insulation board are all organic and GM-free

The last time I wrote about fitting insulation was back in May, and it feels like the job has been dragging on since then. When you look at the YouTube videos, you see time-lapses of people fitting insulation over the course of a weekend. Maybe we could have achieved that if we’d known exactly what we were doing before we started, but we didn’t, so … tough luck, I guess.

To be fair, we haven’t spent all the intervening time fitting insulation, but every weekend, pretty much, we’ve been doing part of the job, just enough to progress some other part of the job: fitting the bench bed, or the shelf above the cab.

But the main source of frustration has been the endless trips to Screwfix to buy more materials – and in particular, expanding foam. This van eats the stuff.  A quick check of my van expenditure spreadsheet reveals we have bought this many cans of expanding foam:

That’s 14 cans.

They’re 750ml each, and the packaging states the contents will expand to 35 times the original capacity. So – ignoring wastage, of which there has been a fair amount – I calculate we’ve sprayed over 26 litres of foam into the cracks and crevices of this van.

Anyway, we’re almost done.

Insulation is one of the most controversial topics on the van conversion forums, with many a certainty bandied around. Our original plan was to use rigid board for the bulk of the insulation, with expanding foam to fill the gaps. I still think that was a pretty solid plan, but I wish I’d known at the time we’d by spraying this much of the stuff.

Rivnuts

Rivnuts (AKA nutserts, and other names) are a type of ‘blind fastener’; that is, they can be fitted through a surface without access to the rear of that surface, unlike, say, a nut an bolt, where you need access to both sides to fit and tighten the nut. The van is full of such surfaces, in fact almost every metal part you’d want to attach something to has no access to the rear surface.

Rivnuts are installed by drilling a hole (e.g. 9mm for an M6 rivnut), inserting the nut with a rivnut tool, and using the tool to compress the rivnut around the hole.

That leaves you with a threaded hole securely mounted to your sheet metal surface, into which you can fit bolts to secure furniture, cladding, and other substantial stuff in the van.

You could say a self-tapping screw is a kind of blind fastener – you just screw it in from one side – but so far, my experience has been so-so. I find they can easily be overtightened, and shear the threads they’ve just cut.  Whereas rivnuts are satisfying to install, can tolerate endless removal and reinsertion of the bolt, and add a level of utility to sheet metal that is almost magical.

Disadvantages

I’ve found a couple of them, just things to be aware of (we’ve had 2 failures out of maybe  100 rivnuts we’ve used, and we’re new to this):

  • Installing: Spinning nuts. If you don’t tighten the install tool enough, the rivnut can be left a little loose, and then it tends to spin in the hole when you tighten a bolt. You can tighten up a rivnut that’s spinning, which seems to work fine.
  • Planning: Finding the hole. Unlike screws, you can’t just drill through the workpiece and the mounting surface in one go. You have to make a hole for the rivnut, install it, then offer up the workpiece, fit the bolt through a hole in the workpiece and hope that the hole in the workpiece lines up with hole in the rivnut. Because the rivnut is fitted perpendicular to the metal surface, and has a precise thread, there is no room for slop. You can drill through the workpiece with a bit sized to your bolt (e.g. 6mm for an M6), and carry on through the metal to create a pilot hole for the rivnut, but this still has to be widened out to take the nut (in this case, to 9mm).

Top tips for rivnut happiness

Steel, not aluminium. Aluminium is softer, so I guess they’re easier to install, but we have no problems wit the steel ones, and they’re more likely to retain their thread when using steel bolts. I use the plated carbon steel (CR3 or BZP) not the more expensive stainless steel rivnuts.

Cylindrical, not hexagonal. You can buy rivnuts with a hexagonal external profile. The hexagonal nuts give ‘high torque resistance‘ (i.e. they’re less likely to spin, but I found them impossible to install in round holes in the 1-2mm steel sheet of the van. The splines on the round rivnuts seem to provide plenty of resistance for our usage.

Standard head, not low-profile. The head protrudes above the surface of the sheet metal, which prevents a flush fitting of the workpiece. But I found that this could be easily overcome by countersinking the hole on the rear of the workpice to accomodate the head of the rivnut. The payoff is that the standard head makes for better load bearing.

Use a good tool. I bought a proper rivnut tool, which was not too expensive, and works fine for the M5 and M6 steel rivnuts we’re using – it should go up to M8.

We’ve bought from several sources, but I’d recommend these:

£3.60 for 50 x M6 rivnuts from Memfast.