Putting a cover on your radiator can serve two important functions. First, it prevents anyone in the family from touching the hot metal and getting scalded, and second, it camouflages the somewhat unattractive heating appliance. As a bonus, you'll get a little extra shelf space.
Radiators generate heat by circulation of steam or hot water. That means the maximum operating temperature is 212 degrees Fahrenheit, so there's no danger of your cover catching fire no matter what material you use to make it.
Designing a DIY Heater Cover
A radiator cover isn't much more than a box with grate-covered openings that allow air to circulate. The choice of materials is up to you. Hardwood, softwood, plywood and medium-density fiberboard, or MDF, are all good choices, although you'll probably want to stick with inexpensive and grain-free MDF if you plan to paint your project.
The cover is basically a three-sided box with a front panel. The front has a cutout for the grate, and to improve air circulation, the sides should also have cutouts. While it's important to make the front cutout as large as possible to maximize airflow, you can be creative with the sides. Make a single cutout or a series of holes on each side. The holes can be round, square, triangular or star shaped depending on your skill with a jigsaw.
An important feature to include is an access port for the bleed valve, which is on the top or the side of the radiator. Whether you cover the hole with a hinged panel or not, it should be big enough for your hand and positioned in such a way to allow steam to escape.
Cut Out the Pieces
You want the cover to extend about 4 inches past the front of the radiator and about 2 inches above it. If you have a table saw, you can rip the material for the sides and top to the proper width yourself, or you can buy predimensioned material. Cut the material to length with a circular saw.
It's easiest to make the front of the radiator cover if you use plywood or MDF. Cut a panel to the proper height and width, draw an opening on the panel that reveals as much of the radiator as possible and then cut out the opening with a jigsaw.
Assemble the Cover and Attach the Radiator Grate
Use the glue-and-screw method to assemble the cover or, if you prefer, use finish nails. If you choose to nail MDF, it's best to do it with a brad gun to avoid bent nails and chipped material.
Once you've assembled the unit, the last thing to do before setting it in place is to attach the radiator grate. Cut pieces of decorative wood or metal mesh that are about 2 inches wider and longer than the holes over which they go. Secure them from behind with staples or with screws and washers.
Finishing Your Radiator Cover Project
Just before setting the cover in place, improve heat circulation in the room by placing a piece of sheet metal between the radiator and the wall. This reflective material will amplify the heat generated by the radiator.
Place the radiator cover over the radiator and secure it to the wall using corner brackets. If you don't want the fasteners to show, you can also construct a frame on the wall using 1 x 2 material and screw the cover to the frame.
The project is finished unless you wish to trim out the radiator cover with decorative molding and paint it. That's up to you.