A Papier Mâché Electronic Enclosure
January 22, 2011 15 Comments
A few years ago my wife attended a Papier Mâché (paper pulp) art class. She taught the rest of us one technique called layering. In this technique you glue small pieces of paper inside or outside a mold in layers. You can glue a few layers at a time, let it dry, and add more layers. At the end you can leave it as is, paint it, and/or lacquer it. Once you have more than about 7 layers, the object becomes quite stiff and strong. At that time I made a nice pen holder using a food container as a mold using this technique, and that was it. But I kept wondering whether the technique could be used to make enclosures for electronic projects. A few weeks ago I decided to give it a try and to build an enclosure for the Softrock Ensemble II RX. You can see the result in the picture above.
I did not have a plastic box with the correct dimensions to serve as a mold, so I decided to start with a skeleton box made out of thin corrugated cardboard. I cut the skeleton out of a packaging box, which you can see in the picture on the right. I designed the size to fit the receiver and glued the sides using flaps that I left on the sides of the box. I left the top open. On the sides, I glued rectangles of the same material that extend below the bottom of the box, to serve as feet. I left the top open and made a lid our of two rectangles of cardboard, one to fit over the box and a smaller one that would fit into the box, so that the lid does not move. You can see the cardboard that I used for the skeleton on the right, along with some pieces of magazine paper that I used later in the layering process. I didn’t count the number of layers I glued on the skeleton. I just kept going, letting the box dry once in a while, until it felt stiff enough. The corrugated cardboard skeleton is pretty soft, so it took quite a few layers to get the box to be stiff. I used regular PVA glue (white glue), diluted with water.
In the picture on the right you can see the box and lid almost ready. I used pages out of a magazine for the layering. At that point, I switched to white printer paper, to get a white box. When the white paper covered the box, I made the holes for the mounting screws and for the connectors. I started with small holes made with a hand drilled, and then enlarged them as necessary with larger drills, a hobby knife, and a round file. The strength of the material is similar to that of soft wood, so it’s not hard to shape the holes. Once the holes were made, I glued thin strips of paper through them (part of the strip on the outside of the box and part on the inside) to stiffen them. I then glued another sheet of paper on the front.
That’s it. It took many hours to make the box. As you can see in the pictures below, the enclosure does not look mass produced (indeed it was hand made). Whether you think that this is a good thing or a bad thing is a matter of taste. I like it.
Here it is with the lid open.
I didn’t find a good way to make the lid latch closed. I can always glue a piece of paper covering both the lid and the bottom part, but as long as I want to tinker with the receiver, I’ll keep the lid separate. Even once glued, it should be easy to separate the top with a hobby knife if I need to.