How To Fasten Cabinet Fillers
Image illustrates how to fasten a cabinet filler to the cupboard side by using clamps and screws. All fillers must be pre-drilled with a three sixteenths inch (3/16″) drill bit before fastening them with screws. As you can see in the photo, the side scribe is carefully clamped perfectly flush with the face of the boxes front edge. IT is not required to have additional help to do this if you have enough clamps to hold the wood in place.
Some cabinet installers like to fasten the pieces on from the inside of the kitchen cabinet rather than from the outside. Every situation will be different depending upon the size of the wood filer piece that you are installing.
For more information you can visit here:How To Attach Fillers On To Cabinets