Drill a straight hole 28" - Need advise

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Forum topic by becikeja posted 11-14-2018 12:52 PM 714 views 0 times favorited 12 replies Add to Favorites Watch
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1005 posts in 3266 days

11-14-2018 12:52 PM

I have a 16” diameter maple log that is 28” tall. I have carved a scene into the outside (will post when finished) and now need to drill a hole through the center to run a lamp cord. My plan is to use a 16” long, 1” diameter spade bit and drill from the top and bottom and hopefully connect in the middle. I will start with a forstner bit about 4” in that will hopefully serve as a guide, im hoping to get this under my drill press so I can make sure to start straight. Does this sound like it will work? Any other suggestions? I am open to all ideas.

-- Don't outsmart your common sense

12 replies so far

View Fresch's profile


441 posts in 2374 days

#1 posted 11-14-2018 12:58 PM

I have a shopsmith so would put it into horizontal drill mode. I have drilled 8’ with it before. But then I have drilled from the attic to the basement laying on my stomach free hand, I have many heavy duty extension shafts made by Greenlee
I would start with a 1/4” bit as a pilot first and just eyeball it 1/2 way each end.

View John Smith's profile

John Smith

1924 posts in 616 days

#2 posted 11-14-2018 01:24 PM

the common bit extender comes to mind.
(connect two 12 inchers plus the drill bit to go all the way through in one pass).
[and I second the (1/2”) spade bit over the forstner for a long run.
a forstner “could” overheat and become lodged in the wood].
also: in a 16” diameter log, the through-hole does not have to be straight.
it can be crooked as a dog’s hind leg and still be usable – all you need is
a hole that you can pass a cord through – that’s all.
and then some way to hold a 2” long threaded nipple firmly in place.

EDIT: “assuming” you are going to use the standard lamp socket with the
threaded hollow rod ??? keep in mind that if you use the large 1” bit to start
the top hole, you need to have a plan as to how you are going to hold the
threaded nipple firmly in the wood. I think it is about 3/8” outside diameter.



-- I am a painter. That's what I do. I paint things --

View jonah's profile


2075 posts in 3752 days

#3 posted 11-14-2018 02:04 PM

Wouldn’t an augur bit be better than a spade? I can’t picture getting a spade bit through that much material in any kind of straight fashion.

View johnstoneb's profile


3123 posts in 2626 days

#4 posted 11-14-2018 02:16 PM

What ever method you use keep moving the bit in and out to keep the hole clear of chips. You do not want the bit heating up and seizing in the hole.

-- Bruce, Boise, ID

View Tony1212's profile


329 posts in 2188 days

#5 posted 11-14-2018 03:04 PM

Admittedly I know nothing about what you’re going for here, but you said you were open to all ideas!

Did you think about a 90 degree hole? Drill down through the top as deep as you want, then drill a hole from the back, parallel to the top, to meet the first hole? Or maybe even a diagonal hole that starts at the top and exits out the back?

This obviously won’t work if you want a 360 degree viewing with no other adornments.

-- Tony, SW Chicago Suburbs

View Lazyman's profile


3713 posts in 1840 days

#6 posted 11-14-2018 03:08 PM

+1 on using something other than a spade bit. It will be easier to get a straight hole with a twist or auger bit because the bit itself helps keep it heading in a straight line. The long flutes will also help clear the chips for a easier time at it. Also, as John mentioned, use the smallest bit you can. No point in removing any more wood than needed. I think that Home Depot sells an 18” drill bit extender by Milwaukee but it may require 1/4” hex bits. I am sure that you can find an extension to fit whatever bit you use if you look around.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View Phil32's profile


598 posts in 356 days

#7 posted 11-14-2018 04:55 PM

Since the centering of the hole at the bottom of the lamp is less critical, I’d suggest drilling the entire hole from the top end using more bit extenders and removing chips frequently.

-- Phil Allin - There are mountain climbers and people who talk about climbing mountains. The climbers have "selfies" at the summit!

View becikeja's profile


1005 posts in 3266 days

#8 posted 11-14-2018 11:50 PM

I looked for a long auger style bit but could not find one. Never considered an extender. That may just be a better approach. I did think about cutting a 90 degree hole through the back but I really want the cord not to be seed at all.

This is going to be a challenge.

-- Don't outsmart your common sense

View Eric's profile


79 posts in 326 days

#9 posted 11-15-2018 12:24 AM

I have been reading up on boat building. And from that the best way to drill a long hole is with a augar bit, used with a bit an brace. Once the hole is started switch to a barefoot augat, one that does not have a screw point on the tip.

Good luck with your project.

-- Eric, Upstate South Carolina

View John Smith's profile

John Smith

1924 posts in 616 days

#10 posted 11-15-2018 12:30 AM

you have 22 very impressive projects on your profile page.
I don’t know why this one has you so baffled.

when you get it all figured out, instead of drilling a hole in the bottom for the cord
to come out, cut a groove in the bottom of the log and glue the cord in the groove
with hot melt glue. then, glue a piece of felt or heavy material to the bottom of
the log (covering the cord) to protect the table that it sits on.
natural lamps are fun to build – once you do one, you get the “itch” to do more !!!
if you over-think it ~ it will surely be over-thunk !! and you are way over thinking this !!
(I lived in Key West, Florida for 6 years and one of my hobbies was making household items
out of driftwood. I can not remember how many driftwood table lamps I have made).


-- I am a painter. That's what I do. I paint things --

View runswithscissors's profile


3057 posts in 2478 days

#11 posted 11-15-2018 02:18 AM

As Eric says, the barefoot auger is your best bet. They are (or were) used to drill propellor shaft holes, sometimes through a long piece of deadwood timber. I believe they may be still available. Used, if not new. They not only lack the center screw but have only a single cutting edge or flute.

Alternatively, many lathes have a hollow tailstock through which you can run a drill bit. You spin the work, not the bit. Lacking a barefoot auger, you might try a bell hanger’s bit. My local hardware store has those.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View Fresch's profile


441 posts in 2374 days

#12 posted 11-15-2018 01:03 PM

IRWIN Industrial Tools 47416 1-Inch by 17-Inch Tubed Long Ship Auger Bit $25 Amazon

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