Creating a van like this has been a dream of ours for years, and realizing this dream took a lot sacrifice. Sprinter's arent particularly cheap or easy to find, so acquiring just the right one meant cashing in most of our savings and a taking a trip to the east coast to pick one up. Sprinters are much more expensive on the west coast, particularly in the Portland area since there are so many like minded individuals competing for the same models. We really wanted this particular model of sprinter ('06), as it is the older body style which gets better gas mileage than it's newer counterparts. We also wanted the 140" wheel base version, which is essentially the medium size. This is as large as you can go while still fitting in a standard parking space. It is important to us to be able to stay nimble, and not be confined to staying in RV parks and large campsites.
The conversion process took about 6 months, and cost about $6k beyond the intitial cost of the bare bones van. It is still not 100% finished, as we still have a few finishing touches here and there, but we couldnt be happier with the way it turned out so far!
Step 1: CAD Design
Designing the van in CAD was key to our successful build. It allowed us to go through several design iterations, each one getting more and more detailed/fleshed out before we ever bought any materials. When we were satisfied with the design I was able to essentially "explode" all of the cabinets into individual parts and precisely figure out material yeilds. Most of the plywood elements were cut by my brothers over at OregonTrail'R (thanks guys!) which saved ton of time on my end. I cut out a few last minute/afterthought details on my own homemade CNC as well. After all the parts were cut, and cabinets assembled, the moment of truth came when I had to see if they all puzzled together and fit well in the van. They did! Without a 1/4" to spare, everything fit like a glove almost as if it was all painstakingly designed and engineered that way....
After a ton of research I determined that the best, easiest, and actually most affordable way to insulate the van was to pay a professional to spray foam th entire cargo area. I found a local professional to do it for about $200. The catch is that this did not include any prep work or finishing. I started by masking of the floor and cab area with painters plastic. I then masked off all of the ribbing and areas that I planned to attach my paneling to with blue painters tape. This proved to be a very good decision. Last but not least I masked off the rear door area to allow the foam guy access without overspraying all over the doors, also a good decision. The spray foam guy was great, and got the whole job done in about 15 minutes. To my surprise the foam was try to the touch almost instantly, and much more dense and heavier duty than the "Great stuff" you can buy in the cans at hardware stores. He was able to completely fill the cavities, keeping low and high spots to a minimum, which I could tell took some expertise. He praised me for my foresight in masking everything off, which was truley key to the whole operation, as it is a messy process involving a ton of overspray. This stuff really sticks too, so it would be a nightmare to try and carve all of the foam off of the ribbing if I had not masked them off. Luckily I did, so I was essentially able to break/peel the foam off of all the ribs relatively easily. The harder part was trimming off high spots in the foam to ensure that my paneling wouldn't have bulges here and there. Instead of grinding the foam with a sander or angle grinder and creating a huge mess/toxic hazard, I decided to just take my time with a very flexible utility knife (Tajima) and slice them down bit by bit. This took a while, but I didnt have to wear a respirator in the midsummer heat. Once that was Done I Filled in as much of the ribbing as a could with "Great stuff" and called it good. An important step to note was that I ran all primary wiring BEFORE any of this foam business.
As for paneling, I decided to go with a prefinished 1/8" baltic birch plywood. I found this to be the best option, as it is flexible enough to bend around all the gradual curves, it's thin profile doesn't eat into the living area at all, and its prefinished face looks great and repelled dirt and moisture. It was also came in 5'x5' panels, which was ideal for the Sprinters form factor. Luckily our van came with some plastic paneling still intact, so I was able to use them as templates to accurately cut around the wheel wells. This helped quite a bit, but after that it was just a lot of winging it and making it work. I did luckily have the forsight to glue some wood blocking in some key areas along some of the larger spans to help keep everything sturdy and aligned. I decided not to try to kerf and bend the plywood into the tight top corners, and instead screwed some full length 3/4" baltic birch plywood along the legnth of the van just inside the corner as an anchor point for cabinets later on. I then trimmed that runner with some more of the 1/8" prefinished ply.
Step 3: Cabinetry
This is the part of the build that I looked forward to the most. That is until I realized just how many parts I was going to have to sort through and store in my modestly sized garage woodshop. By the time I got all the parts accounted for and organized, I had no room to actually assemble. I probably spend just as much time during this step stacking and re-stacking piles of wood as I did actually assembling cabinets. This was very frustrating, but it got easier and easier as I finished each cabinet and loaded them into the van. I started with the upper cabinets, and installed them as I finished each one. I hung them with a combination of construction adhesive and pocket screws. The majority of the strength comes from pocket screwing each vertical section to the previously mentioned 3/4" stringer that I mounted to the inside corner of the ribbing along the full length of the van.
The cabinets all went together fairly easily, thanks to the fact that the parts were precision CNC machined out of 1/2" baltic birch which was prefinished on both sides. This eliminated having to finish each cabinet after assembly, and the factory finish is more durable and aesthetically pleasing anyway. All I had to do is wipe a little Watco oil on any exposed endgrain.
Step 4: Kitchen and Electrical
From the very begining of the design process we placed a lot of emphasis on the cooking situation. We knew that we would be living in the van for an extended period of time, and wanted to eat well without too much of a hastle everyday. This meant that we had to an oven, and range, a hood, and a sink with running water. To make this design challenge even more complicated, I decided that I wanted the propane and water tanks to inside the van as apposed to beneath. This decision was based on several factors. For the propane, I never liked the idea have having it mounted beneath because they always hang a bit low on Sprinters, and we plan to be hitting some heavier terrain. I dont want have to worry about denting or puncturing a propane tank on top of all of the other concerns in a situation like that. I also wanted to be able to easily swap and fill the propane tank without having to craw around at the base of the van. Another concern for me was that propane tanks have to be checked and recertified fairly often, and a smaller 20lb tank is always easier to deal with. My solution was to create a "propane locker" beneath the oven which has two vents to the outside of the van. One vent goes out of the side of the van, and one goes out the floor. The idea is that propane is heavier than air, so if there is a leak it will always sink out of the lower vent, drawing fresh air through the higher one. The locker has a gasketed door, essentially isolating the tank from the inside airspace.
As for the water tanks, I also wanted to keep them inside for multiple reasons. For one, they will be less prone to freezing in the winter, and getting too hot in the summer. Ideally we would keep the living space a mild temperature, which would in turn keep the water at a more manageable temperature as well. I also did not like the idea of having to find an appropriate water spigot/fillup station and getting out a hose everytime we wanted to refill our water, so I opted for four 5 gallon jerry cans stored under the sink instead. 3 for fresh water, (one painted black for solar showers), and 1 for grey water. This way if a can runs empty, we just swap to the next one via quick disconnect, and we can fill the empty one just about anywhere, including any drinking fountain, or a nearby stream via our Sawyer water filter. We chose a hand pump faucet coupled with an electic pump with foot pedal activated switch. When we are stealth camping we can simply use the hand pump to avoid the unnecessarily loud noise of the electric pump. When noise is not a concern, the foot pedal allows us to save water much more easily by only running the sink after a dish is soaped up, and not constantly having to turn the water on and off by hand.
Step 5: Custom Roof Pods
We knew that we would need some sort of roof pod situation to house our large zero gravity camp chairs, collapsible picnic table, and extra blankets and such, while also accommodating-2 large 100W solar panels. There is only so much real estate on top of the sprinter, so I decided to maximize space and usable flat surface area for the solar panels by creating our own custom form fit roof pods. Having worked at a sign shop creating crazy shapes out of flat cardboard and plastic all day, this seemed like an achievable mission. I decided to use a material called Choroplast, which is essentially the same thing as cardboard, only made out of a lightweight waterproof/UV resistant plastic. This material can easily be cut and creased to create all sorts of origami inspired shapes. I created the Dielines in Cad, mocked it up on regular old computer paper, and decided to give it a go. The Idea is that the rear two sections are large containers with flat tops for mounting the solar panels.
Both containers can be opened/hinged from either side of the van, allowing us to aim the solar panels in either direction to better catch the sunlight when necessary, as well as allow better access to their contents. The front portion of the pods is just a form fit air deflector to help keep wind resistance and gas mileage in check. The shape had to be fairly complicated to accommodate the fantastic fan that we previously installed. These shapes turned out to be surprisingly rigid and sturdy for being made out of 4mm thick mostly hollow plastic. Since Choroplast is relatively soft and could be punctured by low hanging branches, I clad every out-facing surface with 1/8" thick polymetal to act as armor plating. This material is also fairly lightweight, as it consists of a HDPE plastic core with thin aluminum faces. These "armor plates" also helped to make the whole system much more rigid than it already was.