Boring a hole in a stump ????

Dan Mosley

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Palm Springs, Ca
I received a email from a relative asking me if I could think of a way to bore 3-4" holes in a tree stump. First question is why do you want to do that ? He stated he had someone turn the stump round more or less on a large lathe leaving some inclusions etc......the wood pattern he said it very nice and will finish nicely but he wants the holes bored into it so he can put it in his office as a holder for blueprints of some sort............

Well, oooooook.........without buying a expensive machine and then a auger bit I would have no idea so I thought I would ask the people on here about how he could do that..........................buying the bit is one thing but a machine to drill it out is another........not sure..........thoughts??
 
well i am not sure if yu can get forstner bits that large dan but if its possible then a floor model drill press will do it with extension rods to make the bit longer..just watch your speed and take it easy your taking alot of wood out at a time and the torque is gonna be high..
 
Suppose you could use a hole saw and chip out the waste when you hit the bottom of the bit. It'll take forever though.
 
Forstners do come that big, I have a 3 1/2 incher.
But, to keep costs down, I believe I would get out my biggest bit and drill a series of holes to dimensions wanted. Then I would use a chisel, whatever kind is available, flat or a carvers gouge, and clean up the sides. Lotsa elbow grease and armpit sweat would be involved but it would do the job.
 
ok a couple questions for you first. How big diameter stump, how many holes, how deep the holes will be or if they go all the way through and will these holes be through the end grain or cross grain in the stump
 
the diameter is about 18+ or bigger - boring the stump in at a slight angle and going to approx the center or there abouts - it does not have to be exact as far as depth -
 
FWIW, I found some German made large Forstner's on line for sale.
Prices are quite expensive.
A 3" is about $200.00; 3 1/2" $300.00 and a 4" is $400.00.
But, if this guy wants to do something in a commercial way he will have to pay for professional level tools.
 
FWIW, I found some German made large Forstner's on line for sale.
Prices are quite expensive.
A 3" is about $200.00; 3 1/2" $300.00 and a 4" is $400.00.
But, if this guy wants to do something in a commercial way he will have to pay for professional level tools.

Both lee valley and grizzly have 3 inch forstner bits. I wouldnt worry to much about the bit as long as you dont overheat it, any bit should have no problems drilling a couple holes. I'd be more worried about what your going to use to spin this hugh bit. Your gonna have problems drilling at an angle unless you use a drill press
 
Since you don't care about the quality of the holes, and since even a 3" spade bit would be a bear to work with freehand, I'm going with Frank and Larry's idea. Drill, chisel, drill, chisel.

I had to make a 6" hole in the back wall for a dryer vent. First through concrete block, then through brick. Drilled around it with a good sized bit, then chiseled out. Then drilled some more. It took most of a day, and my biggest drill. You can get extra long bits even at home depot.

Buy several... ;)

Thanks,

Bill
 
You could use the hole saw to get a nice clean side. You can buy the cutter for about $20-25 if you have an arbor already. Every couple inches would need to drill/chisel the waste out but it would work and leave nice round holes.
 
Sounds like a perfect job for boring.


Drill the largest hole you can then take a hardwood dowel or steel rod that fits well but turns freely. Cross drill it and insert a 1/8 inch lathe tool with a set screw drill at 90 degrees. Set the bit out a tad and insert the dowel or rod in your drill Drill down 1 inch or so. Bring it back up and move the tool bit out some more. When you have used up all your tool bit add a longer one and start the process over. When you have full diameter turn a disc and insert it over you dowel or rod and start back to the small diameter. Now repeat what you did earlier until you are about 1 inch from the bottom. Keep steeping the diameter up till you are as big as needed. Leave the bottom plugged or remove the last inch or so however you chose, Sounds complicated but really goes pretty quickly in wood. Drill needs some power and low rpms.

The disc in the top and the material left in the bottom act as the bearing for you boring bar.

The larger hole and dowel or rod you start with the less work there is of course...
Garry
 
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ok I figured it out, Just go to the gun range, see what type of round makes a hole closest to 3 inch and fire away :thumb:

The idea for a 3 inch hole saw sounds better than a forstner, and Im thinking if you buy a hole saw set and drill 3" then use the same center point to drill 2 smaller sized hole saws in the waste of the 3" you should be able to pry the waste part out and drill the 3 inch deeper, probably will need an drill extension though.
 
I received a email from a relative asking me if I could think of a way to bore 3-4" holes in a tree stump. First question is why do you want to do that ? He stated he had someone turn the stump round more or less on a large lathe leaving some inclusions etc......

Put it back in the lathe and have whoever turned it round make the hole, they should be able to make it any size he wants.
 
There has been some curiosity about my big bit.
It is big. Pics attached.
BTW, it has a 1/2" shaft and fits in my Griz drill press.
 

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