Some chalk lines can be used as plumb-bobs. This is a useful feature if you need to create accurate vertical guidelines or transfer points from ceiling to floor. It will also eliminate the need for you to purchase a separate plumb bob tool.
It is helpful if your chalk line has a tapered point on the bottom of its body. This will promote accuracy when using it as a plumb bob (particularly if you are transferring points).
To use your chalk line as a plumb-bob is fairly simple. Follow the steps below to do so:
Step 1 – Pull out string line
Firstly, you will need to pull out a length of the string line. This should be equal to or just shorter than the length of the object or surface you want to make or mark as plumb.
Step 2 – Attach hook
Attach the hook to the top of your object (or on to a nail if necessary).
Make sure the string line runs directly from the bottom of the hook because if it is askew or tied to the side, it may give an inaccurate line.
Step 3 – Suspend chalk box
Now that you have attached the hook, the chalk box should hang from it and, because gravity will always pull the object directly downwards, the string line will give an accurate vertical (plumb) reference line.
Step 4 – Impart plumb line (optional)
You can use the string line as a reference or impart a chalk line onto the surface.
If you want to impart a line onto the surface, hold the box and secure the string line with a finger so that it is taut. Pinch the middle of the string line between your index finger and thumb and lift it 10-15cm (4-6 inches) off the surface, then release. By releasing the string line you will cause it to “snap” back down to the surface and impart a chalk line.