Rear spoilers on cars provide numerous advantages, some of which include increased downdraft and hence greater ability to stick to the road, better aesthetics and more equal weight distribution on the frame of the car. However, some stock or aftermarket rear spoilers are not tall enough to fulfil their purpose for one reason or another and therefore require the use of risers. Risers are pieces of body putty or fibreglass that are moulded to resemble the foot of car spoilers and provide an extra height advantage when installed between the boot lid and the spoiler itself. It is possible to buy spoiler risers, however they can just as easily be made yourself with a little ingenuity and a bit of time. Follow these steps to make your own.
Begin by removing your rear spoiler from your boot lid. Lay the spoiler feet down on the cardboard and use the marker to trace around the feet. This will become your pattern for the spoiler risers. Mix up some Bondo putty and let it harden.
Spread a layer of putty onto the cardboard pattern when the Bondo is the consistency of peanut butter. Build a layer 2 to 3 inches deep of putty and use the putty knifes to shape the riser to resemble the foot of your rear spoiler. This does not have to be exact as you will shape it later, but try to get it close.
Allow the putty to dry until tacky and then spread another 2- to 3-inch layer of putty on top of it. Continue this process until the desired height has been reached. Allow the putty to dry until completely hard (24 to 48 hours). Using the band saw, shape the sides of the putty to more closely resemble your spoiler foot. Fine tune the design with the razor blade knife and sandpaper. After thoroughly cleaning the riser of any dust or dirt, paint with the appropriate colour of car paint, drill holes for the spoiler mounting bolts to go through, and mount the rear spoiler on top of the risers.
If you build your risers and they are too tall, use the band saw to cut a section crosswise from the bottom of the riser. This allows you to remove height, but not start from square one all over again.
When painting and using the putty, be sure to wear eye protection and gloves, as the chemicals associated with these substances can be harmful.