A wood core bit is generally a form of the conventional drill bit. However, the significant difference lies in the waste product given off after cutting. It is similar to a hole saw but removes a core- a solid cylindrical piece gotten from the cut. Whereas, other forms of drill bit give off dust.
We have put together this article to provide insights on best practices when using a wood core bit. By the end of this read, you would have gotten few tricks up your sleeve on handling core bits.
Fig. 1: Close-up image of wood core bits.
Table of Contents
1.Keeping the bits sharp
While some wood core bits are self-sharpening, others require sharpening from time to time. You also need to bear in mind that “one sharp tool is better off than many blunt tools.” When your core bit needs sharpening, it seizes to perform as expected. You might want to conclude it’s a mechanical issue when your bit becomes dull, but it just needs sharpening.
To determine if your core bit is blunt, you would observe that the teeth are slightly rounded and difficult to cut. In extreme cases, the wood rips. Another act that can quickly dull your core bit or even break it is when you place too much pressure on the drill machine in a bid to quicken the drilling process.
If you finally decide to sharpen your wood core bit, you have the option of doing it yourself or sourcing the expertise of professionals. Should in case you choose to do it yourself then you can get it done using a fine triangular file. If you can bear the cost, then a universal sharpener is the way to go! You should start by using a permanent marker to mark your starting point to avoid a double revolution.
It is worthy of note that the triangular file is manual while the universal machine is automated.
Fig. 2: Image showing the sharpened teeth of the core bit.
2.Mind your speed and torque
The quest for the right RPM drilling wood can be quite tasking. High RPM might likely burn your wood. If you drill too slow, you might still ruin the job. For cases where the hole won’t be visible at all, a slow drill could still be allowed. For the record, finding the right speed is mostly dependent on your level of experience. The type of wood in question also plays a great part in deciding the speed to apply.
Following best practices, we recommend that you start slow and carefully increase your speed. It is no gainsaying that softwood will allow for a reasonably high speed compared to hardwood. It is obviously due to the ease of getting through the wood.
Maintaining a slow speed at first will help your core bit tip last longer and prevent damage to your wood. In a case where you have to bore through a wood completely, you should slow down your speed upon arriving close to the exit.
In general, high speed fits wood drilling. Most hand power drills have an adjustable speed via a knob that you can work with to achieve your aim.
Fig. 3: Hand power drill in operation with the core bit.
3.Stop Intermittently between drills.
While drilling, especially thick/hardwoods, the core bit would need rest at the interval. “This is also called the stop and cool technique ” -the purpose of resting is to avoid overheating of the core bit. When the core bit becomes very hot, it gets blunt faster and requiring you to spend more time or money to sharpen it frequently. You should keep a bowl of cold water close-by whenever you can intermittently dip in your core bit for a few seconds to cool it off. Stopping intermittently also eliminates the chances of burning your wood. This act also affects the overall life of the core bit.
In a situation where you are drilling a hole all through the wood, endeavor to do it in steps. Failure to do it in steps could leave the back of the wood looking rough and jagged. You would do yourself good by adhering to this factor to have a fine and smooth final cut.
Fig. 4: Picture showing a core cut out of wood.
4.Create an Indents before commencing
The need for an initial indent is pivotal to making a pilot hole. A center punch and hammer creates an indent at the desired center point to commence drilling. With an indent in place, you should never go wrong. This indent guides your entire drilling process; without it, great mistakes abound. The pilot hole is smaller in diameter than the required hole size, but it is important to create one initially.
With an indent and pilot hole, your job is of high precision and accuracy.
Fig.5: Picture showing center drill for creating a pilot hole.
When drilling, you would want to avoid a tear-out because it makes you feel less of a pro. Taping and the use of a sacrificial/ scrap board can save the day in situations such as this. Marking an X- shape with painter’s tape helps to prevent chipping or cracks in surrounding areas where drilling starts. Slowly progressing your core bit into the wood also eliminates the chances of a tear-out. In other cases, not properly securing your workpiece in place can lead to the tear-out of large chips.
The sacrificial board is, on the other hand, fastened to the back of the workpiece to support it from behind. In all, if you desire to avoid a tear-out watch out for your drill’s exit speed.
6.Clean the bit after use
For every tool or device, it is an established practice to always clean after use to ensure longevity and durability. Below are a few steps to be taken in cleaning your core bit after each job:
Dust off debris from the wood and your workpiece to avoid possible scratch every five to ten minutes when drilling.
Once your wood core bit cools off after an intense job. Get a clean, dry towel to wipe the outer and inner parts of the bit from top to bottom. You can hand-spin the core bit while the towel still wrapped around.
For the teeth, use a clean brush to remove any stuck wood material.
After carrying out steps 1-3, faintly apply a coat of machine oil around the core bits. If you have a handy case return them there. If otherwise, keep in a cool and dry place free of any natural elements that could deplete its quality.
Having satisfied all the procedures as mentioned earlier, be assured you got a durable and long-lasting core bit.
7.Have two sets of core bits
It is ultimately an optional tip in a bid to maintain accuracy. Most professionals trust a new set of core bit to start a hole. Then they switch to an older set to complete the task.
The reason for this is not far-fetched at all. This approach keeps your new bits sharper for a long time, thereby saving you from frequent sharpening to achieve a good cut.
Fig. 6: Picture showing sets of core bits in a handy case.
8.Observe all safety measures.
Keeping safe at all times is a must. You should not take it as a joke or trivial matter. Below are few precautionary measures to follow to ensure a safe working environment and condition both for yourself and drill:
Keep hands straight
Drilling is not all that difficult, but the slightest offset in the position of the core bit can ruin your job. It happens when you use a hand power drill. The indent and pilot hole, as well as another board placed on top of the workpiece, helps maintain squareness. If you own a drill press machine, you need not bother as the default configuration is perpendicular.
Do not realign once you start drilling
If, for any reason, you drift off the hole as you drill, do not attempt to exert pressure. Do not correct your mistake as by forcing your drill to one side as further mechanical complications could arise. These complications could lead to the breaking of your core bit and even the dulling of the teeth.
Store and keep bits in carrying case when not in use
Always keep away from heat, moisture, etc. when not in use. It gives your core bit a lustrous feel and appearance at all times.
Secure the workpiece in a clamp, vice or any fence
Regardless of whether you are using a drill press or hand power drill, you need to secure your workpiece properly. This singular act could reduce the rate of hazard by up to 50%.
Having digested this article, we believe you would have learned vital tips to help efficiently use wood core bits.NCCuttingtools is always ready to respond at the snap of your finger to render any help you need. In situations where you fall into distress or dilemma and need professional advice as regards all range of cutting tools.