A double bullnose router bit is designed to create a small impression on the side of wood, stone or other building materials being used with a cutting machine. The double bullnose can be used to make two peaks (the bullnose pieces) at the same time, saving effort. If you use a double bullnose router bit, you can cut this shape into a stack of stone or wood without having to make the same pass more than once. The double bullnose bit is most often used by experts, as it can be a complex device, but if you already have the tool, it makes sense to use it rather than hire someone else to do the work. Learning how to use the double bullnose is worthwhile and can be done by following a few simple guidelines.
Step 1 – Get Your Stack Into Place
The first step is to secure the stack you intend to cut. Before you place the router piece onto the machine, check that the stack of stone (or wood) you intend to cut is laid upon the table and is secured using the table belts, or ties, in order to prevent them from moving when you are using the tool. Some cutting tools will have a system which allows you to grip the stack in place while pulling the router along. Once the stack is secured, you are ready to use the router.
Step 2 – Place the Router on the Tool
Fit the router into the tool. As with most cutting blades, these will screw onto the bottom of the cutting tool. The router should have a long central screw onto which all the blades will be fitted. You may have to remove the blade you used previously, and then fit the bullnose onto it, turning it slowly until you have a small amount below the router. Secure the bullnose bit in place by fitting a nut onto the bottom of this long screw.
Step 3 – Make Your Cuts
You can now begin to cut the stack. If your tool is stationary, you should position the stack so the side you wish to impress is level with the router bit. Touch the stack to the router, and slide it through the cutting tool, as you would when cutting pieces on a jigsaw. If the cutting tool is manual, run this along the stack, keeping the cuts to the same depth.
Step 4 – Finishing
Before you finish the project you will have to smooth down the stack using sandpaper. You may wish to practice making the cuts on some waste pieces of stone or wood before you start cutting into pieces you plan to work with.