Drilling Deep Holes in End Grain
Is this even possible? I seem to always find a way to accommodate goofy architects but this one I am having a hard time with.
From contributor J:
The bit is likely to drift off course drilling a hole that deep in end grain. Some people use an air-cooled bit to help alleviate that problem.
From contributor R:
Ship auger bits are designed to do what you want. They are available in 18" lengths so you will still need an extension or two.
From contributor H:
Dado a groove in the back of the post and fill it with a glued wedge half the depth of the dado. Or put the wire in and then fill with the wedge.
From contributor D:
I have drilled out 7 foot reclaimed columns to be used for lamp bases by running a length of pipe up the hole around an electricians auger bit. The auger tip really pulls the bit, but the pipe seemed to steady it, and I was able to direct it fairly well. I drilled from both directions; not as accurate as the Chunnel but it worked.
From contributor C:
I once saw a man twisted into a knot while using a shipauger bit. That is the tool for the job in my opinion, but you had better be sure to extract it every few inches to clear the chips or it will bind up and if your drill is powerful enough it will twist you in a knot. We welded pencil rod to the end to bore really deep holes.
From contributor A:
This may sound weird, but it actually worked for me when I had to deep drill a precision hole. As the others suggested, we used a deep boring bit with an extension. What we did to ensure that the bore was truly vertical was to station two helpers 90 degrees apart.
Each person eyeballs a sight line ensuring that the drill bit and newel post are parallel. If you drift a little in any direction, your helpers tell you left or right, and you make the slight adjustment as needed.
From contributor S:
I recognize this is an extremely deep hole but you would be surprised at how well a simple jig with a drill bushing clamped to the post can work. Bushings are available in different diameters and different lengths. A longer bushing will obviously help you stay straight on a deeper hole. Bushings help remove any lateral movement of the drill. That is one reason they help keep holes accurate and bits sharp when drilling steel. If you have ever drilled steel on a press and then with a hand drill you will appreciate that drilling with a hand drill and a bushing is closer to drilling on a press than freehand. Also you can start with a smaller diameter hole (if the bit is available) and ream the hole to finished dimension after.
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