David Sweeney took an automotive approach to building his own custom camper trailer.

This is how you make your own custom camper.

Long-time camping fanatic David Sweeney knows a thing or two about welding. The Tamworth-based tradesman has taught panel beating apprentices and trainees for more than 25 years, so when he decided to build a camper trailer he knew exactly how it ought to be done. The camper had to be suitable for fishing trips, coastal holidays and desert adventures with his wife Kaye and their three sons.

"I wanted something strong enough to support a tinnie but light enough to tow offroad." said David.

The plan was to build a steel space frame and incorporate welded and bonded sheet metal panels to increase the structural strength of the trailer, similar to what you would find in a current model car.

"The steel used in the main supporting structure of modern motor vehicles is often less than 1mm thick. Granted, we're talking about specialised high-strength steels, but the way box sections
are welded together helps give the main structure its strength."



David chose 100x50x2.5mm Supagal for the drawbar, 50x50x2mm Supagal for the space frame, 1.6mm galvanised sheet for the floor and 1.6mm zinc annealed steel for the side panels, and set about designing the trailer around the gear.

"I bought the running gear and components first. I wanted the camper to follow the tracks of my 4WD, and the wheel rims and tyres to match my tow vehicle so that I always have two spares for the entire rig.

"I needed to find the right axle before I could figure out the width of the trailer base and the location of the drawbar."

David settled on a solid axle fitted with seven leaf rebound spring suspension and electric brakes over 16in rims. Initially, he could do without power, but a water supply was essential so he purchased an 85L water tank with plumbing for two outlets: one for the kitchen and another  for outside.

"I also had camping gear that wanted to include like my 110L EvaKool icebox, which fits in the front box."

David marked out the dimensions on the garage floor with masking tape to check that the frame and body was square throughout the build and laid out the gear to determine where it would go.

"I paid a great deal of attention to where the OzTrail kitchen would sit, and made sure the tailgate would swing out without a problem."

David researched bedbases and camper trailer tents to identify the optimal size and drop from the bed to the floor, which helped cement the width and the height of the frame.

"Most camper trailer bedbases are designed to suit a 1.2x2.1m box trailer."

As the body frame dimensions took shape, David carefully measured each piece of 50mm RHS square, cut it and placed it out on the floor like a jigsaw. He then tack welded it until he was confident that all the dimensions were correct.

David cut and folded the steel to create the box sections in his brother Peter's workshop.

The next step was to attach the floor of the trailer and toolbox using a high bond strength material which improved the camper's structural integrity and created a seal. The remaining sides of the trailer and toolbox were then fitted, with all the sections welded and bonded for extra strength.

The doors and lids were built, the compression locks and pinch weld seals fitted and the trailer was prepared for paint.

David made room for the spare tyre on the toolbox as well as the swing away spare wheel/bike rack to suit his requirements. He built the boat rack for the 3.5m tinnie and allocated space on the drawbar for the motor. David fitted a removable checkerplate box at the front for storing firewood or extra gear and fitted 4.5kg gas cylinders and a 20L jerry can holder on the trailer's left side.



Although a great deal of effort and forethought had gone into the trailer, many canvas producers met David's request for a quote with some trepidation.

"A lot of tent manufacturers weren't interested in seeing their tents on an untested trailer - for fear of damaging their name - until I showed them the photos of the trailer, that is."

With so much thought and effort going into the build, David wasn't compromising on the tent.

"I went with Explorer Campers & Canvas in Gosford.

"They insisted on fitting the tent to the trailer - which is what I preferred."

David liked the quality of the locally made and sewn canvas, the high canvas roof and the fact that all the windows open and close from the inside during inclement weather. The zip-on annexe walls were also supplied in three separate sections rather than as one giant full annexe wall.

"I like the elastic straps on the tie downs on the canvas; the tent is always under tension but is flexible in windy weather."

David estimates that the project cost him $13,000 - not bad considering the trailer has been used on every holiday except bar one since late 2009.

"I am pretty happy with the overall result."

Since completing the camper in 2009, the Sweeneys have toured Kinchega National Park near the Menindee Lakes, Sturt National Park, Warrumbungles and visited the coast about half a dozen times.  David reckons the pinch weld seals easily handled a deep crossing on the way to Tilpa from Wilcannia.

Modifications include adjustments to the boat rack, longer storage drawers in the kitchen and a new 12V LED lighting and power system, which includes five internal 12V outlets and a 100Ah deep cycle battery.

"The biggest difference would have to be the 12V system. We used 12V as well as a new hot water system on our last bush camping trip to the Flinders Ranges."


Originally published in Camper Trailer Australia magazine #62, February/March 2013