A door knocker installation that uses the through the door mounting method requires drilling holes through the door. Care must be taken when drilling these holes.
Depending on the size of the hardware being used these holes may be up to 3/8 inch in diameter. There are things to think about on both sides of the door before you drill.
Once their exact location is determined the holes must be drilled squarely through the door. The door knocker will lie flat on the outside surface of the door. The mounting lugs are machined into the back of the door knocker so that the hardware must enter at a perpendicular angle. If the holes through the door are not square the hardware will not screw into the door knocker casting.
It is a good practice to have the finished holes large enough so that the mounting hardware fits loosely into them. A very tight fit may do well on the day that the installation is made but if your climate is like ours, there is as much as a 100 degree temperature difference from summer to winter. Changes in temperature causes expansion and contraction. This could cause damage to your door or your door knocker over time if the fit is too tight.
The actual drilling of the holes can damage the door. It is a good practice to first drill holes at the precise mounting locations that are less than half to size of the finished hole. The smaller hole would be drilled all the way through the door. This smaller hole gives you the chance to check your work as well as provides a guide for the finished holes.
With the smaller holes drilled through the door at the exact mounting locations you can drill the finished larger holes. Do not drill the finished holes all the way through. This would have the potential of damaging the surface of the door where the drill exits.
Instead, drill the hole half way from one side and then drill the rest out from the other side of the door. This will provide clean entrance points on both sides of the door.
With a little planning and careful work your door knocker installation will be a pleasing addition to your home for years to come.
