Building the camper box

Posted 28 January 2020 by Vegard

After some research we decided to make our camper box out of GRP sandwich panels. We searched the Internet and found that the ideal and most common thickness for such panels is between 50-70 millimeters. Most sandwich panels are made up by a relatively thin layer of fiber glass on both sides, with a closed-cell type foam in between, possibly with reinforcements casted into places exposed to additional loads or stress. The combination of these materials makes a super sturdy construction with excellent isolation properties, while still having a low total weight.

After deciding on the size and positioning of windows, hatches and doors, we made a 3D model of the camper box, and started looking for manufacturers of GRP panels. We quickly realized that the marked for this type of panels is almost non-existing in Norway. Luckily, at the same time the marked was booming in Germany with several companies offering custom made panels. We eagerly e-mailed a couple of them asking for offers. Although we did get several replies, they were all way higher than what our budget allowed, thus we were left massively disappointed.

Shortly after all the negative feedback, it was time for the annual “Abenteuer Allrad” fair in Bad Kissingen, Germany. We thought it might be a good place to search for a supplier, and we thus made sure to bring multiple copies of the construction drawings we had made for our camper box. Then we put on the big smile and went out searching for the perfect deal. This turned out to be a great idea, as there were several companies represented, producing either complete camper boxes or just the separate panels. We ended up with a small, but serious company called Paneel-Tech GMBH. They were helpful and engaging, and at the same time one of the best when it came to price and estimated delivery time.

The type of panels we ended up with was consisted of a 1.5mm thick outer layer of fiberglass reinforced with a 3.5 mm thick layer of honeycomb extruded fiberglass. This was again covered with white gel coat in color RAL 9016. Then followed by a 49.3 mm thick layer of insulating foam (“closed-cell” type), reinforced with wooden beams and plywood sheets on specific places for added strength and stiffness. Finally, the inside was covered with a 1.2 mm thick layer of fiberglass, thus resulting in a total thickness of 55.5 mm.

After doing some minor adjustments to our drawings, to simplify the production, the guys at Paneel-Tech set to work. The panels were casted in a large vacuum press, to ensure perfect bonding and super finish. They also cut out the big openings for the storage hatches, doors and windows. Eight weeks later, the panels were ready for pick up at their factory in Thüringen, Germany. Due to expensive shipping costs for the lightweight, but bulky panels, we decided to go and pick them up ourselves.

When we got back home to Norway and it was time for the assembly. The panels came with corner profiles, glue, and a detailed instruction on how to assemble them into a box. At this time, it was autumn the temperatures were already dropping below freezing point at nighttime. The cold weather made the process painstakingly slow, as the glue took almost a week to cure. Since we could only glue one panel at the time, the whole assembly process took almost two months!

Finishing the box was a big milestone to accomplish, and we weren’t disappointed with the result. With the help of two large overhead travelling cranes the completed box was assembled onto the Unimog support frame in no time at all, and we suddenly had ourselves a camper truck!