30/01/2020
If you want to use a core drill or holesaw, here are a few tips that may help you. I will just refer to holesaw from here on in but the tips generally work for both.
• Firstly after marking out wherever you want your hole, drill a pilot hole using the pilot drill that comes with your core holesaw set. Do this before putting the hole saw onto the arbour, this way you have a guide for the holesaw, also a lot of the times you cannot see where you marked the hole once the holesaw is on the arbour as the hole saw covers your markings.
• Set your drill on the screw setting (if you have it) and set the number at a point you can cope with. If you set it at the midpoint to start with, if the clutch kicks in and the hole saw is not cutting you can increase it to a higher setting. I suggest this because if you use the holesaw with your drill set to drilling, a lot of the times the holesaw will stop but the drill itself will then rotate, this can hurt your wrist or worse.
• If struggling to drill a core drill hole in wood, start drilling the hole so that it at least scores the surface then you can drill relief holes just inside the score marks. This will reduce the pressure required to drill and help remove the dust.
• If you have drilled the wrong size hole. I can offer three options to get around this. First, drill a hole in a piece of ply to the new size that you want, then cover the old hole with this piece of ply and use the ply as a guide clamping it down if possible. Secondly, wrap masking tape around the plug that came out of your first hole until it is a snug fit, then push the plug into the hole (if you have time you can just glue this plug in) and then use the larger holesaw along with the pilot hole as a guide to drill the new hole. The third option is to put your new larger holesaw onto the arbour then screw the smaller holesaw onto the arbour and use the smaller holesaw as a guide for the bigger holesaw.
• If however you have drilled the hole in the wrong position or have an existing hole, mark where you want your new hole, then drill a hole in a piece of ply, place this over where you have marked where you want the new hole. Again if possible clamp the ply down. With this method, you do not need the pilot drill.
• To stop breakthrough, this is when you drill a hole with the holesaw and instead of a neat hole when the holesaw comes out the other side, a lot of the back falls off giving an unsightly hole. This is very easy, all you need do is dill your pilot hole first so that it comes out the other side of the piece of wood that you want a hole in. Then you drill one side with the holesaw for maybe 3-6mm then flip the job over and drill from the other side.
• Final tip, if you want to drill a hole with a holesaw that is deeper than the holesaw can manage, you can either apply the above technique of drilling one side then flipping it over and drilling from the other side, or drill as deep as you can then remove the plug from the hole saw and then drill again in the same hole.
When I made the video I showed another option but I would suggest you only do it this way if you are really confident.