Outside In: Cutting and Drilling Into Metal

1. Prep the Van

Once you have your van, bus, or trailer and you have a layout in mind, you’re ready to get started! The first thing you want to do, especially if you’re buying used, is to inspect and clean the body; make sure the skeleton is in good shape before adding the meat.

If you encounter rust, it’s imperative to remove it all before moving forward. Use an abrasive wheel, sand paper, or a grinding wheel with a wire brush to remove the rust and paint until clean metal is visible. If it’s so bad that there are holes, cut the rotten parts out and patch it up by welding a piece in or replacing the part. Another option would be to spray any rust with a treatment that transforms it into a non-rusting, paintable surface (link).

Any exposed metal where the paint has been removed should be covered in rust preventative paint or spray paint (link).

2. Cutting and Drilling Holes

When removing rust and cutting or drilling into metal, use the appropriate safety protection, like safety goggles (link), ear plugs (link), a facemask (link), or work gloves (link).

The tools most commonly used for cutting and drilling holes in vehicle walls, and for other aspects of a conversion, are a jigsaw (link) and power drill (link).

For cutting large holes for a vent fan or window, a jigsaw with a metal cutting blade is ideal. To get started with cutting, you’ll need to drill holes that are large enough for the blade to fit inside, either at the corners or along a radius if a curved cut is required. After the holes are drilled, the dots can be connected with a jigsaw until the metal can be removed. Use a rasp or file (link) to smooth out any rough edges.

3. Installing a Vent Fan

I bought a Fan-Tastic Fan (link) which is built to only blow in one direction, so I installed a DPDT switch that allows the flow to be reversed (see the Electrical Installation page). There are nicer fans with a thermostat, built in reversible flow option, and built in rain cover, like the Maxxair 05100K (link). There are also cheaper ones that may not provide ideal air flow, but get the job done, like Heng’s 71112-C vent fan (link).

A vent fan is essential for providing ventilation to air out condensation, fumes and carbon monoxide from propane use, and food or body odors. To get started on the installation, find an appropriate location for a 14” x 14” square (or however large the vent is) that wouldn’t affect the structural integrity of the vehicle and would be over where you cook, sleep, and/or lounge. Drill holes at each corner and cut out the piece with a jigsaw.

After the edges are smoothed down, spray them with rust preventative paint and allow it to dry.  Place butyl tape (link) along the edges of the hole, place the fan on top, and screw the fan into the roof with the provided screws.

Sealant is needed to cover the butyl tape and to make sure the edges are completely sealed. Sikaflex 221 (link) is designed to be weatherproof and resist the shock and vibrations of driving, so they’re ideal for vehicle conversions.

There are smaller vent fans that can be used as a dedicated exhaust point for a propane appliance, like the Ventline VP-543 (link). This vent requires a circular hole using drilled holes along the circle, rather than making straight cuts.

There are smaller vent fans that can be used as a dedicated exhaust point for a propane appliance, like the Ventline VP-543 (link). This vent requires a circular hole using drilled holes along the circle, rather than making straight cuts.

4. Installing a Window

If you plan to install a window, there are ones that can be bought specifically for a vehicle model for certain locations on the vehicle and there are aftermarket RV windows that can fit on any flat wall (large window link, smaller window link).

A vehicle window typically comes in two parts: the inner trim (‘beauty ring’) and the outer window. First, create a template of the portion of the outer window that would extend into the van by tracing it onto cardboard and cutting it out. Before installing the window, you may have to remove a nonessential vertical support with a chisel.

Then drill holes at the ends of the curves at the corners, trace the template on the outside, and cut along the line with a jigsaw. Painters tape around the outer edge of the line can be added to avoid having the base of the jigsaw scratch the vehicle surface.

Your window may be made for a wall that is much thicker than the wan metal thickness. This would require a spacer frame made of 4 pieces of thin lumber so that the inner trim can be firmly fastened to the outer window. Glue the spacer frame to the inner van wall around the large hole using clamps (link).

Once the glue sets, apply butyl tape to the inside of the outer window, overlapping the ends by ½”. Then place the outer window on the outside of the van, placed the inner trim onto the spacer frame, and start installing the screws into the trim to clamp it to the outer window. Finally, cut the excess sealant tape along the outer edge of the window and seal it with Sikaflex 221.

5. Installing Solar Panels and Wiring

There are flexible solar panels that can stick directly to a vehicle roof for stealth, however, they’re pricier and are more prone to issues with internal connections, so they may not last as long.  Rigid solar panels require space between itself and a vehicle roof for airflow. Mounting brackets (link) can be used at each corner of a solar panel.

If you have a large solar panel, have the front of the panel rest on the van roof, and keep the back suspended a few inches off the roof. This required spacers underneath 4 mounting brackets (2 on both sides at the center and 2 on both sides at the back) and two 6” aluminum angle bars on both sides at the front. Drill holes in the angle bars and solar panel where they would attach, and connect them with nuts and bolts.

A cable entry housing (link) is used to transfer the solar panel wires from the roof to the inside of the vehicle, so the wiring is protected from sharp metal edges and the connection is waterproof. Solar wire extension cables (link) are typically needed for the wiring to reach the solar charge controller; connecting the wires requires MC4 tools (link).